Minimize ISS Utilization: JEM/Kibo-EF

ISS Utilization: JEM/Kibo-EF (Exposed Facility) experiments

Experiments in JEM/Kibo focus on space medicine, biology, Earth observations, material production, biotechnology and communications research. Kibo experiments and systems are operated from the Mission Control Room in the SSOF (Space Station Operations Facility) at the Tsukuba Space Center (TKSC) in Ibaraki Prefecture, Japan, just north of Tokyo.

For this presentation of “ISS Utilization: JEM/Kibo,” the emphasis is on Earth observation instruments, technology introduction, and observation of environmental effects. The Earth observation payloads are accommodated in the external JEM/Kibo-EF (Exposed Facility).

The JEM-EF is an external platform for conducting scientific observations, Earth observations, and experiments in an environment exposed to space. The JEM-EF/payload interface on the JEM-EF side is the EFU (Exposed Facility Unit). There are a total of 12 EFUs on the JEM-EF, nine of which are available for users. The other three EFUs are used for the JEM-experiment logistics module (ELM)-exposed section (ES) and for temporary storage. Figure 5 is a general view of the JEM/Kibo facility; Figure 6 is a block diagram of the EFU locations on the JEM-EF. In general, the JEM-EF services its EFU payloads with electrical power, data, and active thermal control. 1) 2) 3)

• Power: The layout is such that each EFU provides 3 kW of main power and 100 W of survival power on two separate buses.

• Communications: The JEM-EF provides eight high-data-rate channels, eight video data channels, and seven Ethernet channels.

Number of payload allocations

10 payloads (5 for JAXA, 5 for NASA)

Payload mass

500 kg max. for each port; (2,500 kg max. for special port)

Payload size

1.85 m x 1.0 m x 0.80 m (for standard payload)

Electric power consumption

3 kW max. for each port, 120 VDC


Low rate: 1 Mbit/s max. (MIL-STD 1553B)
Medium rate: 10 Mbit/s max. (Ethernet)
High rate: 100 Mbit/s max. (FDDI)

Exhaust heat

Cooling medium (16 to 24ºC)

Table 1: Overview of payload accommodations on the JEM/Kibo-EF 4)



Delivery of JEM/Kibo-EF Payloads on the HTV-1 (H-II Transfer Vehicle-1):

Launch: The HTV-1 resupply vehicle of JAXA was launched on Sept. 10, 2009 (UTC) from the TNSC (Tanegashima Space Center) in Japan, representing the maiden flight of HTV to the ISS. JAXA launched the HTV demonstration flight aboard the newly developed H-IIB launch vehicle. About 2 hours later, the HTV-1 reached its target orbit. 5) 6) 7)

• The flight profile had the unpiloted HTV-1 was taking seven days to reach the ISS so ground controllers could run various tests and demonstrations on its maiden voyage before rendezvousing with the space station.

• Unlike previous resupply ships that docked directly to the station, the HTV approached to within 10 m from the ISS on September 17, 2009 - from where it was grappled using the Canadarm2 robotic arm of the space station (also referred to as SSRMS). Then, astronaut Robert Thirsk (Canada) used Canadarm2 and moved the HTV spacecraft to the nadir port of the Harmony module. Shortly after 22:00 hours UTC on Sept. 17, 2009, the HTV-1 was mated to the ISS.
Actually, the scenario was more elaborate: In a true display of international cooperation, American flight engineer Nicole Stott, using Canada's Canadarm2, captured the Japanese HTV-1, with help from Belgium's Frank DeWinne and Canada's Robert Thirsk, under the direction of Russian ISS commander Gennady Padalka.

• On Sept. 23, 2009, Canadarm2 was again used to extract two science experiments from inside the cargo craft and placed them onto the JEM/Kibo module’s external platform.


Figure 1: Artist's rendition of the HTV-1 approach to the ISS and capture by Canadarm2 (JAXA)


Figure 2: Artist's view of the unloading of the Exposed Pallet from the HTV (image credit: JAXA)

• HTV-1 delivered about 4500 kg of cargo and resupplies (propellant and batteries) to the ISS. The two EF payload instruments on this flight were:

- SMILES (Superconducting Submillimeter-Wave Limb-Emission Sounder) of Japan (total mass of 475 kg). At launch, SMILES was fixed to the HTV EP (Exposed Pallet (EP) via a standard interface mechanism (TS-P).

- HREP (HICO-RAIDS Experiment Payload) which are two payloads of the USA (total mass of 381 kg). Both of these payloads will be mounted onto JEM/Kibo-EF (External Facility).

• On orbit, JEMRMS (JEM-Remote Manipulator System) catches EP and carries it to EFU (Exposed Facility Unit) of JEM-EF. - Then SMILES is carried by using the JEMRMS (after the SMILES temperature is raised using heaters), and connected to EFU-3 port. After its one-year operations support, SMILES will be loaded onto the HTV and disposed into the atmosphere.

• All the cargo transfer operation from the HTV PLC (Pressurized Logistics Carrier) to the ISS was completed on October 20, 2009.

• The HTV-1 remained docked to the Station until Oct. 31, 2009. After being loaded with waste, the HTV-1 undocked and departed from the ISS. The HTV reentered the atmosphere on November 2, 2009. The vehicle with its debris fell into the South Pacific Ocean. 8)

APBUS (Attached Payload BUS)

The APBUS was developed to service the Kibo Exposed Facility (EF) payloads. Each experiment/payload is mounted onto the Kibo Exposed Pallet, grasped by the Kibo RMS (Remote Manipulator System), transported to the predetermined position, and then installed at the predetermined port of the Kibo EF. 9)

The various handling logistic tasks - launch, onboard transportation, and installation - require the payloads to be equipped with special attachments: PAM-PU (Payload Attach Mechanism-Payload Unit), GF (Grapple Fixture), and/or PIU (Payload Interface Unit). All attachments are subject to accurate alignment/interface requirements for installation.

JAXA developed a “mission interface structure” to satisfy all interface requirements for the payloads to be handled. This resulted in two types of support structures: BStr (Box Structure), and PStr (Pallet Structure).





aluminum alloy

Size of container

760 mm (height), 800 mm (width),1,850 mm (depth)


230 kg

210 kg (including PIU, GF, PAM-PU)

Maximum exhaust heat capacity (passive)

300 W

180 W (Depends on exhaust heat area)

Equipment loading ability

500 kg

400 kg

Table 2: Main parameters of the mission interface structure


Figure 3: Illustration of the BStr (left) and PStr (right) transport containers (image credit: JAXA)

Subsystems needed for BStr and PStr service provision:

HCE (Heater Control Equipment): HCE detects experiment equipment temperature and keeps experiment equipment warm by providing electrical power to the heater in case the sensor detects a preset temperature. HCE has a mass of 2 kg, power: 330 mA (supply current), and a controllable temperature range of -44º to +1ºC

APRT (Attached Payload Remote Terminal): A specific communications protocol for Kibo is used on ISS and Kibo (MIL-STD-1553B). Signals of experiment equipment need to be converted to the Kibo specific communications protocol to perform experiments on the Kibo. APRT converts signals of experiment equipment to the Kibo-specific communications protocol. APRT has a mass of 6 kg.

PDAP (Power Distribution box for Attached Payload): A 120 V electrical power supply is provided on the Kibo EF. Additionally, experiment equipment must satisfy specific interface conditions (ex. load characteristics) to connect to the Kibo EF. PDAP can meet above conditions and transform electrical power to 28 V that is easy for experiment equipment to use. Besides, PDAP can distribute electrical power to multiple lines (12 channels max). PDAP has a mass of 7 kg.

EMA (Extension Mechanism Assembly): Some Kibo EF experiments need an extension from the main structure. EMA was developed for this purpose. EMA can extend up to 1 m with the experiment equipment on the tip of an extendable mast. Also, EMA can stow the extendable mast within the mission structure as required.

EMA is equipped with LLM (Launch Lock Mechanism) to positively fix the extendable mast during launch and landing (Shuttle requirement), and to release the extendable mast to perform experiments on the Kibo EF.


Figure 4: SEDA-AP extended configuration (image credit: JAXA)



JEM/SMILES (JEM / Superconducting Submillimeter-wave Limb-Emission Sounder):

JEM/SMILES is a joint instrument development of JAXA and NICT (National Institute of Information and Communications Technology). The overall objective of SMILES is to demonstrate a sensitive submillimeter-wave sounder implementation (limb emission sounding method) and to monitor global distributions of stratospheric trace gases. The principal investigator (PI) of JEM/SMILES is Harunobu Masuko. 10) 11) 12) 13)


Figure 5: Accommodation of the JEM/SMILES payload in the EF (Exposed Facility), image credit: JAXA


Figure 6: Overview of attachment positions of the JEM-EF payloads (image credit: JAXA) 14)


Figure 7: Cutaway view of the JEM/SMILES instrument (image credit: NICT, JAXA)


SMILES payload:

SMILES is the first instrument to use a superconductive low-noise receiver with a mechanical 4 K refrigerator in space. SMILES is an instrument concept designed to measure with exceptionally low noise stratospheric trace gases that have only weak spectroscopic signatures. Its unique feature is a SIS (Superconductor-Insulator-Superconductor) mixer (heterodyne detector technology), a device that has so far not been operated in space since it works only if cooled down to 4.5 K.

The performance of this state-of-the-art SIS receiver, with an estimated SSB (Single Side Band) receiver noise temperature of 500 K at 625–650 GHz, provides a large improvement in sensitivity compared to the conventional submillimeter-wave Schottky-diode receivers used by the SMR (Sub-Millimeter Radiometer) onboard the Odin satellite (3000 K, single side band, 485–580 GHz, cooled) and the MLS (Millimeterwave Limb Sounder) onboard the Aura spacecraft of NASA (12000 K, double side band, 625–650 GHz, uncooled). - Since the integration time reduces by the square of the system noise temperature (receiver noise plus atmospheric noise contribution), this performance is roughly equivalent to reducing by a factor of up to the integration time needed to reaching the same noise equivalent brightness temperatures. SMILES measurements thus have the potential to provide meaningful information on the global distribution of short-lived radical species, such as HO2, ClO, and HOCl. 15)

The SMILES bands have been selected to allow the measurement of various trace gases that are important for the understanding of stratospheric ozone chemistry, notably ozone itself including its isotopes, and several chlorine compounds. 16) 17) 18) 19) 20) 21) 22)

While the compact SIS receiver, operated by a mechanical 4 K cooler, is being regarded as the most critical technology introduction, there are in addition other key technologies needed, such as a high-precision antenna, submillimeter optics, a submillimeter signal source, a cryogenically cooled IF amplifier, and an acousto-optic spectrometer (Ref. 13).

Demonstration of high-quality data for atmospheric trace gases: The high sensitivity of the SMILES observation data will drastically reduce the errors in atmospheric volume mixing ratios retrieved for various molecular species. Figure 8 summarizes the result of simulation studies. With respect to ozone and HCl, the single-scan data, sampled at 53 s intervals, will be sufficient to retrieve their mixing ratios with errors significantly < 5% (ozone) or 10% (HCl) at any latitudes. As for ClO, which is the most important ozone destruction species, the retrieval error levels estimated with the single-scan data are less than 30% at low and middle latitudes, and less than 10% for the ClO enhancement in the lower stratosphere at high latitudes.

For other less abundant species such as CH3CN, HOCl, HO2, HNO3, and BrO, scource data will be obtained from a half-day zonal mean for a 5º width in latitude, which is produced with 30 pieces of single-scan data. The retrieval errors estimated with such zonal mean are less than 10% for CH3CN at low latitudes, and for HOCl globally. The error levels will be less than 30% for HO2 in equatorial regions and for HNO3 at middle and high latitudes. Those for BrO remain at 50% levels at any latitudes, which however will be improved with observation data that is averaged over a longer period.


Figure 8: Altitude coverage of the JEM/SMILES data estimated from preliminary results of simulation studies (image credit: JAXA)


Subsystem components

ANT (Submillimeter Antenna)

Antenna Reflectors (REF)
Antenna Mounting Structure (MNT)
Beam Transfer Section (TRN)
Cold-sky Terminator (CST)
Antenna Drive Electronics (ADE)
Calibration Hot Load (CHL)

SRX (Submillimeter Receiver)

Ambient Temperature Optics (AOPT)
Cryo-electronics Unit (CRE)
Ambient Temperature Amplifiers (AAMP)
Helium Gas Compressors (HECP)
Submillimeter LO Controller (SLOC)
CRE Control Electronics (CREC)
Stirling & JT Drive Electronics (SJTD)

IFA (IF Amplification Section)


AOS (Radio Spectrometer)

AOS Analyzer Unit (AU)
AOS Control & Video Unit (CVU)

STT (Star Tracker)

STT Camera Units (CAM)
STT Camera Controller (CAMC)

DPC (Data Processing and Control Section)


BUS (Payload Bus)

Electric Power System (EPS)
Mainframe Structure (MFS)
JEM Interface Mechanism (JIF)
Thermal Control System (TCS)

Table 3: Overview of the SMILES subsystems and components (Ref. 13)

The SMILES payload is composed of the following elements: Submillimeter Antenna (ANT), Submillimeter Receiver (SRX), IF Amplification Section (IFA), Radio Spectrometer (AOS), Star Tracker (STT), Data Processing and Control Section (DPC), and Payload Bus (BUS).

• The ANT is an offset Cassegrain antenna with an elliptical reflector of 40 cm x 20 cm, which provides an elliptical beam with a half-power beam-width (HPBW) of 0.08º in elevation and 0.17º in azimuth. The antenna scans in a vertical direction at the rate of 0.1125º s-1, the atmospheric signals are accumulated consecutively within the AOS every 0.5 s. This gives a sampling interval of 0.056º (corresponding to 2.1-4.1 km at the tangent point). The effective vertical resolution to the atmospheric layer is calculated as 0.096º (corresponding to 3.5-4.1 km), which includes the effects of the antenna running in 0.5 s and the broader horizontal response of the antenna. The surface accuracy of the main reflector is designed to be 15 µm, which gives the beam efficiency larger than 90 % for a 2.5-times HPBW area.

The ANT is set to face 45º away to the left from moving direction, which enables to observe from 65º north latitude to 38º south. The instrument scans in altitude (vertical direction) and gets spectrum at each altitude level from 0 km to 60 km. The observation signals received by antenna are transferred to SRX and down-converted to the IF (Intermediate Frequency) signal by a superconducting SIS (Superconductor-Insulator-Superconductor) mixer cooled down to 4 K by a mechanical cooler.

• The SRX is composed of the following elements: Ambient Temperature Optics (AOPT), Cryo-electronics Unit (CRE), Ambient Temperature Amplifiers (AAMP), Helium Gas Compressors (HECP), Submillimeter LO Controller (SLOC), CRE Control Electronics (CREC), and Stirling & JT Drive Electronics (SJTD). The AOPT combines quasi-optically the submillimeter signals from the antenna and local oscillator (LO), while terminating the image band to the 2.7 K cosmic microwave background. Sideband separation, higher than 20 dB, is made by a new-type of Martin-Puplett interferometer. The submillimeter LO is generated by a frequency tripler and doubler associated with a phase-locked Gunn-diode oscillator operated at 106.22 GHz. A quasi-optical circular polarizer, which is composed of a mirror and wire-grid, is integrated in the AOPT to reduce spectral baseline ripples due to standing waves.

• The CRE includes two SIS mixers and four IF amplifiers. The SIS mixers are based on Nb/AlOx/Nb devices and equipped with a corrugated feed horn. They are integrated into a block of submillimeter optics cooled at 4.5 K. Two SIS mixers, by detecting perpendicular polarizations each other, observe the upper sideband and lower sideband separately. Cryogenically cooled IF amplifiers are based on high-electron-mobility transistor (HEMT) devices. Two of them are put at the 20 K stage, and another two at the 100 K stage. They are operated at 11-13 GHz with a noise temperature of about 15 K (for amplifiers cooled to 20 K) and 40 K (for amplifiers cooled to 100 K). The noise temperature of the whole SMILES system is mainly determined by the performance of the SRX. The noise temperature of the SRX is estimated around 500 K for single sideband measurements.

A HEMT (High Electron Mobility Transistor) amplifier in SRX amplifies the IF signal, which is led to the IFA (IF Amplifier). In IFA, the signal is down-converted to the secondary IF signal. The IF signal is then detected in AOS (Acousto-Optic radio Spectrometer).

SMILES has two star tracker cameras (STTs) to determine its real time attitude. STT will determine the attitude of the SMILES mainframe structure with respect to the stellar inertia coordinate. It is then converted to the attitude with respect to the coordinate fixed to the Earth to calculate the position of the tangential point of the SMILES beam.


Figure 9: Block diagram of JEM/SMILES instrument package (image credit: NICT, JAXA)

• The SIS mixers and IF amplifiers are cooled by a 4 K mechanical cooler, which is composed of a two-stage Stirling cycle and Joule-Thomson (JT) cooler. The former has a cooling capacity of 1 W at 100 K, and 200 mW at 20 K. The latter has a capacity of 20 mW at 4.5 K. The total power consumption is about 300 W, including a conversion loss in the power supply. The total mass of the cooler is 90 kg, including the cryostat, helium gas compressors, and power supply. The cryostat, which includes three different temperature stages (4.5 K, 20 K, and 100 K), cold-head of the two-stage Stirling cycle, heat exchangers for the Joule-Thomson cooler, and sophisticated structures for thermal isolation, is designed to be about 500 mm long and 350 mm in diameter.

Observation method

Limb sounding

Observation latitude
Altitude range, altitude resolution

65º N to 38º S
0-120 km, 2 km (the lower limit for observation is ~8 km for water vapor observation)

RF frequency bands of SRX (Sub-mm Receiver)

624.32 - 626.32 GHz LSB (Lower Sideband)
649.12 - 650.32 GHz USB (Upper Sideband)

IF frequency of SRX

11.0-13.0 GHz (LSB)
11.8-13.0 GHz ( USB)

System noise temperature

< 700 K SSB (Single Sideband)

Integration time

0.5 s for each observation point

Input signal intensity

0-300 K in brightness temperature

Spectral resolution, spectral coverage

1.8 MHz (FWHM), 1,200 MHz x 2

Antenna type
Main reflector
Main beam size
Effective antenna beam width

Offset Cassegrain
400 mm (elevation) x 200 mm (azimuth)
0.055º in elevation, 0.117º in azimuth
0.096º (HPBW, elevation)

Instrument height resolution

3.5 - 4.1 km (nominal)

Instrumental error in tangent height

0.76 km (rms, bias)
0.34 km (rms, random)

Sensitivity in brightness temperature (for each scan)

~ 0.7 K (rms) for Tb < 20 K
~ 1.0 K (rms) for Tb > 20 K

Accuracy in brightness temperature (for each scan)

~ 1 K (rms) for Tb < 20 K
~ 3% (rms) for Tb > 20 K

Submillimeter mixer
1st IF amplifier

- 4K cooled, SIS mixer (SIS junction: Nb/AlOx/Nb)
- 20 K cooled, HEMT
- Stirling cycle + Joule-Thompson cooler

Spectrometer bandwidth, resolution

1.4 GHz, 1.4 MHz (3 dB)

System noise temperature; system sensitivity

500 K; 1 K, frequency resolution of 1.4 MHz

Instrument mass, power, size

475 kg, 800 W, 0.8 m (W) x 1 m (H) x 1.85 m (L)

Data rate

< 200 kbit/s

Table 4: SMILES main instrument parameters (Ref. 13)


Figure 10: SMILES observation geometry and simulated spectrum (image credit: NICT, JAXA)


Figure 11: Spectral bands of the SMILES receiver (image credit: University of Bremen)

The designed cooling capacity of the system is 20 mW at 4.5 K, 200 mW at 20 K, and 1000 mW at 100 K. The combination of a two-stage Stirling cooler and a Joule-Thomson cooler has demonstrated the capacity with a power consumption of less than 300 W, including losses of driver electronics. The cryostat has a thermal insulation structure of S2-GFRP straps to fasten its 100 K stage. The 20 K stage of the cryostat is held with GFRP pipes on the 100 K stage, while the 4 K stage is supported with CFRP pipes on the 20 K stage. The cooling system accommodates two SIS mixers at 4.5 K, two IF amplifiers at 20 K, and two more IF amplifiers at 100 K. The mass of the cooling system is 40 kg for the mechanical cooler, 26 kg for the cryostat, and 24 kg for the driver electronics.

Two-stage Stirling cycle cooler and Joule-Thomson cooler are combined to build a 4 K cooler, which accommodates two SIS mixers at 4 K stage, two HEMT amplifiers at 20 K stage, and another two HEMT amplifiers at 100 K stage.


Figure 12: Schematic of the 4 K cooler system for SMILES submillimeter receiver (image credit: NICT, JAXA)


Figure 13: Illustration of SMILES receiver cryostat components (image credit: JAXA)


Figure 14: Photo of the SMILES cryocooler (image credit: JAXA)


Figure 15: Photo of the SMILES payload (image credit: JAXA)


Mission status of SMILES:

• On March 5, 2012, a press release of JAXA and NICT announced the availability of the SMILES observation data to the public. The data released to the public are the altitude distribution of 11 types of atmospheric minor constituents including ozone and chlorine compounds, retrieved from brightness temperature of 625-650 GHz electromagnetic emission measured by SMILES instrument. These data explain chemical phenomena of atmospheric minor constituents in the stratosphere and lower mesosphere; therefore, they contribute to the comprehensive analysis of Earth’s climate change including stratospheric ozone variation (such as the “ozone hole problem”) and global warming issues. 23) 24)

SMILES acquired 6 months of observation data of Earth’s atmosphere till its malfunction of the oscillator component inside the instrument in April 2010.

• Although SMILES was planned for an operational period of 1 year, the SMILES assembly is not working anymore due to a glitch on the part of submillimeter receiver subsystem (Ref. 42).

SMILES collected high-quality observation data for six months until the instrument encountered a failure. These data indicate the excellent performance of the SMILES instrument as the data analysis progressed, and the data are expected to produce a mine of new scientific information. 25)


Figure 16: SMILES observations of ozone, ClO and HCl distributions (image credit: JAXA)

On April 21, 2010, the atmospheric observation of SMILES was halted due to the failure of the submillimeter-wave local oscillator (SLO). The SLO consists of phase-locked Gunn oscillator at 106.22 GHz and multipliers. It is believed the Gunn diode failed by some reason. A possibility of the replacement of the SLO is under discussion. 26) 27)

- SMILES has a unique potential for observation of minor chemical constituents from lower stratosphere to mesosphere. Its low noise performance make it possible to observe daily global distribution of ClO. Thanks to the sun-asynchronous orbit of the ISS the diurnal variations can be derived by compiling the data measured in a few months.

- The initial verification of the performance of the SMILES submillimeter receiver was satisfactory and virtually consistent with the estimation from the measurements on the ground. The SMILES observations were made from October 2009 to April 2010. 28)

- The failure of the local oscillator, a critical component, on April 21, 2010 made further SMILES observation impossible. The possibility of the repair is unknown.

• In early 2010, SMILES started atmospheric observations, and has been functioning very well so far. In-orbit performances of JEM/SMILES instruments were verified in the initial checkout phase. All subsystems satisfied their specifications. 29)

• The first observation data from SMILES has been obtained in October 2009. Figure 17 shows the global distribution of ozone concentrations observed by SMILES at the altitude of 28 km on October 12 JST (Japan Standard Time) 2009; the unit of measurement is “ppmv” (parts per million by volume). 30)


Figure 17: Global distribution of atmospheric ozone concentrations provided by the first data of the SMILES instrument (image credit: JAXA)

• The performance confirmation of the SMILES data processing system started. on October 10, 2009.

• On Sept. 25, 2009, the lowest temperature of the SMILES mechanical cooler reached about 4.1 K.

• Two external experiments (SMILES and HREP) were installed on Kibo's Exposed Facility on Sept. 25, 2009 using Kibo's robotic arm (JEMRMS).


SEDA-AP (Space Environment Data Acquisition equipment / Attached Payload)

The SEDA-AP is an external payload, which was accommodated on the external Kibo Exposed Facility (EF). The objectives of this payload are to take measurements of the space environment (neutrons, plasma, heavy ions, high-energy light particles, atomic oxygen and cosmic dust) in the ISS orbit. Also, SEDA-AP will be used to study the environmental effects of the space environment on materials and electronic devices on the Kibo EF. In parallel, the SEDA-AP will help verify the JAXA APBUS (Attached Payload BUS) technology, which provides necessary functions to payloads mounted on the Kibo EF. 31) 32) 33) 34) 35) 36)

SEDA-AP is composed of common bus equipments that support launch, RMS handling, power/communication interface with JEM-EF, an extendible mast that extends the neutron monitor sensor into space (1 m), and equipments that measure space environment data. SEDA-AP has seven measurement units as follows:

• NM (Neutron Monitor)

• HIT (Heavy Ion Telescope)

• PLAM (Plasma Monitor)

• SDOM (Standard Dose Monitor)

• AOM (Atomic Oxygen Monitor)

• EDEE (Electronic Device Evaluation Equipment)

• MPAC (Micro-Particles Capture) and SEED (Space Environment Exposure Device).

All space environment data, which include the data of SEDA-AP, are open to the public via SEES (Space Environment & Effect System).


Figure 18: Schematic view of the SEDA-AP instrument (image credit: JAXA)

The SEDA-AP assembly has a total mass of ~ 480 kg with an envelope of 1850 mm x 1000 mm x 800 mm (neutron monitor storing condition).

NM (Neutron Monitor) or NEM: The NM measures the energy of neutrons from thermal to 100 MeV in real-time using a Bonner ball detector and a scintillation fiber detector. The Bonner ball detector discriminates neutrons from other charged particles using 3He counters, which have high sensitivity to thermal neutrons. It also measures neutron energy using the relative response, which corresponds to different polyethylene moderator's thickness (6 pcs.). 37)

The scintillation fiber detector measures the track of incident particles using a cubic arrangement sensor on which are heaped up to 512 scintillator fibers. The sensor discriminates neutrons using differences of these tracks, and measures neutron energy by measuring its track length.


Figure 19: Schematic view of the NM instrument (image credit: JAXA, Konan University)

HIT (Heavy Ion Telescope): Using a solid state detector, HIT measures the energy distribution of heavy ions (Li–Fe), which cause single event anomalies and damage to electronic devices. The solid state detector converts loss energy of heavy ions in the detector to electrical signals. The HIT measures an incident particle's mass from loss energy in each layer (ΔE) and the total loss energy of each layer (E) using the ΔE x E method. Figure 20 presents a picture of HIT.


Figure 20: Photo of the HIT device (image credit: JAXA)

PLAM (Plasma Monitor): Using a Langmuir probe, PLAM measures the density and electron temperature of space plasma, which cause charging and discharge of the spacecraft.


Figure 21: Photos of PLAM (left) and SDOM (right), image credit: JAXA

SDOM (Standard Dose Monitor): The solid state detector and scintillator of SDOM measure the energy distribution of high-energy light particles such as electrons, protons, and α particles, which cause single event anomaly and damage to electronic devices. SDOM is capable of discriminating and measuring protons in the 0.9 to 200 MeV range, electrons in the 0.5 to >10 MeV range, and alpha particles > 8 MeV, all within a single sensor SDOM. The goal is to utilize sensors with identical design and performance on several simultaneous missions to obtain a clearer understanding of particle energies and their variability as a function of solar activity, latitude, and altitude. The LPT (Light Particle Telescope), an improved version of SDOM, is flown on Jason-2 (launch June 20, 2008), and in the various LPTs of the TEDA assembly of the GOSAT mission (launch Jan. 23, 2009). Actually, the TEDA (Technical Data Acquisition) equipment on GOSAT are upgraded versions of the LPT and HIT (Heavy Ion Telescope). 38)


Figure 22: Photo of the SDOM device with the external cover removed (image credit: JAXA)

AOM (Atomic Oxygen Monitor): The objective of AOM is to measure the amount of atomic oxygen on the orbit of the ISS (International Space Station). Atomic oxygen interacts with the thermal control materials and paints, thereby degrading their thermal control ability. The AOM measures the resistance of a thin carbon film that is decreased by atomic oxygen erosion.


Figure 23: Photo of the AOM device (image credit: JAXA)

EDEE (Electronic Device Evaluation Equipment): The EDEE measures parts. Single-event phenomena are induced by the impact of an energetic heavy ion or proton. The occurrence of single-event phenomena is detected by bit flips of memorized data, the sudden increase of power supply current, etc.


Figure 24: Photo of the EDEE device (image credit: JAXA)

MPAC (Micro-Particles Capture) and SEED (Space Environment Exposure Device): The MPAC is a device used to capture micro-particles that exist on orbit. Silica-aerogel and gold plates are used to capture micro-particles. After the retrieval of MPAC, the size, composition, and collision energy, etc. of captured particles will be evaluated.

SEED is used to expose materials in the space environment. After SEED retrieval, degradation of these materials caused by the space environment, such as high energy radiation, atomic oxygen and UV, will be evaluated.


Figure 25: Photo of the MPAC and SEED devices (image credit: JAXA)

The maximum duration of the MPAC & SEED experiment will be three years, the longest of its kind in Japan. Three sets of MPAC & SEED are attached on the outside of Zvezda on orbit. One unit is retrieved every year. Therefore, exposure duration of individual units is one, two and three years.


Launch: A launch of SEDA-AP and MAXI took place on July 15, 2009 on STS-127 (Endeavour, 2/J/A). The main flight payloads were: JEM-EF and ELM-ES (Experiment Logistics Module-Exposed Section). The task was to deliver ELM-ES to JEM-EF and transfer ICS-EF (Inter-Orbit Communication System - Exposed Facility), SEDA-AP (Space Environment Data Acquisition equipment - Attached Payload), and MAXI (Monitor of All Sky X-ray Image) to JEM-EF. - Following the transfer of these three payloads, the ELM-ES was transferred back to the Payload Bay of Endeavour for return to Earth.


Figure 26: Scenario of SEDA-AP life cycle (image credit: JAXA)


Mission status of SEDA-AP:

• The SEDA-AP instrument is operating nominally in 2013. 39) 40)

• The SEDA-AP instrument is operating nominally in 2012. 41)

• The SEDA-AP instrument is operating nominally in 2011. SEDA-AP measures the space environment parameters (neutrons, plasma, heavy ions, high-energy light particles, atomic oxygen, and cosmic dust) in the ISS orbit as well as environmental effects on materials and electronic devices to investigate the interaction with and from the space environment at the Kibo exposed facility. While the nominal mission life is 3 years, the science team is requesting an extension of 5 more years. 42)

• The SEDA-AP instrument is operating nominally in 2010. 43) 44)

• On March 31, 2010, the outburst from Be/X-ray binary LS V +44 17 was detected by MAXI which was the first detection of a transient activity in this source. The outburst lasted for almost a month, which has been monitored by the MAXI/GSC in the 2-20 keV band. Follow-up observations performed by RXTE (Rossi X-ray Timing Explorer) revealed the sinusoidal pulse profiles with a period of ~205 s. On April 6, 2019, the pulse profile had a sharp dip structure when the luminosity was near the maximum. The dip was clearer in the lower energy bands. The project infers that an origin of the dip is an eclipse by the accretion column. 45)

• SEDA-AP data observations were started on August 25, 2009. 46)

• Initial function checkout of SEDA-AP began on Aug. 4, 2009 (activation of each component, extension of the mast which is equipped with a Neutron Monitor (NEM)). 47)

• Oct. 2012: The MPAC&SEED payloads developed by JAXA, which were installed on the exposed portion of Zvezda (a part of the Russian segment) of the ISS, have been found to have captured a new extraterrestrial material with unprecedented mineralogical characteristics. The material has been named "Hoshi." Hoshi means “star” in Japanese. 48)


MAXI (Monitor of All-sky X-ray Image)

MAXI is an instrument designed and developed by a consortium of institutions: JAXA, RIKEN, Osaka University, Tokyo Institute of Technology, Aoyama Gakuin University, Nihon University, and the University of Tsukuba. MAXI consists of X-ray slit cameras with high sensitivity. The objective is to monitor the variability of astronomical X-ray objects over a broad energy band (0.5 to 30 keV). The instrument is capable to sample more than 1,000 X-ray sources every 96 minutes (~orbital period) covering the entire sky on time scales from a day to a few months. 49) 50) 51) 52) 53) 54) 55) 56)

The MAXI instrument design uses simple X-ray eyes, eight combinations of a slit and orthogonally arranged collimator plates, which produce one-dimensional X-ray images along sky great circles on twelve position-sensitive proportional counters GSC (Gas Slit Camera) in the 2-30 keV band and two X-ray CCD units SSC ((Solid-state Slit Camera) in the 0.5-10 keV band.


GSC (Gas Slit Camera)

SSC (Solid-state Slit Camera)


Proportional Counter Xe+CO2 (1%) gas

X-ray CCD

Energy range

2-30 keV

0.5-10 keV

Detector area

5350 cm2

200 cm2

FOV (Field of View)

1.5º x 160º

1.5º x 90º

Energy resolution


< 150 eV at 5.9 keV

Position resolution

1 mm

0.025 mm (pixel size)

5σ detection limit for one scan

7 mCrab

20 mCrab

Table 5: Characteristics of the MAXI X-ray cameras

Note: “ 1 mCrab” is a unit to describe the X-ray intensity defined as 1/1000 of the intensity of the Crab nebula. X-ray astronomers use this unit when comparing observations from different X-ray detectors on different instruments.


Launch: MAXI was launched on July 15, 2009 on STS-127 (Endeavour, 2/J/A).


Figure 27: Schematic view of the MAXI instrument (image credit: JAXA)

The SSC consists of two units: a horizontal one and a zenithal one. Each unit consists of a slit collimator providing a 1.5 x 90º FOV, and 16 CCD chips as a one-dimensional position sensitive detector. Each CCD chip is about 2.5 cm x 2.5 cm in size with 1024 x 1024 pixels (pixel dimensions: 24 µm x 24 µm). Its architecture is full frame transfer.

To achieve the energy resolution of 143 eV FWHM at 5.9 keV, the CCDs must be operated below -60ºC. To cool CCD chips, a one-stage Peltier cooler is attached to the backside of each CCD chip to produce a temperature gradient of ΔT = -40ºC between the chip and a SSC unit body. Each Peltier cooler consumes typically 1 W (in total 32 W for two SSC units). The heat from the Peltier coolers is transported by a LHP (Loop Heat Pipe) from the SSC units to two radiators on MAXI, this system is called LHPRS (Loop Heat Pipe and Radiator System). Each SSC unit carries a radioactive source (Fe55) as an X-ray energy calibrator.

The GSC is composed of 12 proportional gas counters developed by Metorex Co and which are sensitive to photons with energies in the 2-30 keV. The GSC has an effective area of 6000 cm2 and it is being developed by RIKEN in collaboration with JAXA.

MAXI will be accommodated on the EF (Exposed Facility) of JEM which has 10 ports designed for holding payloads. These attachment ports are called EEU (Experiment Exchange Units). MAXI will be installed on EEU #1 which is located on the corner of the JEM-EF (ram side), a position that gives it the best field of view.

The MAXI instrument mass is 530 kg, the approximate size is: 185 cm (length) x 107 cm (high) x 80 cm (width).


Figure 28: Allocation of the MAXI instrument on JEM-EF (image credit: JAXA)


Figure 29: Illustration of the GSC FOVs of the MAXI instrument (image credit: JAXA)


Figure 30: Photo of the MAXI instrument (image credit: JAXA)


Figure 31: Overview of the MAXI data transmission system (image credit: JAXA)

Legend to Figure 31: There are two downlink paths for the MAXI data. The MAXI team is responsible for the MAXI payload and its ground system as well as for the MAXI mission, including the rapid distribution of observational results. The MAXI data will be transmitted via the Internet through a secure one-way path.


Mission status of MAXI:

• April 19, 2013: MAXI has detected the remnant of a hypernova explosion in the direction of Cygnus. Since the explosion was 100 times as large as those of standard supernovae, the remnant was assumed as a hypernova. On the Milky Way Galaxy we live in, hypernovae and the remnants have never been discovered. This discovery is the first time in the world. 57)

Outside the Milky Way, eight hypernovae and two remnants have been discovered until now. While numerous hypernovae have been discovered because of their extremely bright emission, remnants are difficult to discover because they are as dark as the normal remnants of supernovae, which makes difficult to distinguish one from the other. For these reasons, the Hubble Space Telescope is used to conduct precise observation.

Since August, 2009, the X-ray CCD SSC (Solid-state Slit Camera) onboard MAXI has been observing the high-temperature area in the all-sky configuration. Some wide high-temperature emission was observed in the direction of Cygnus. As a result of the project's analysis, it was concluded that there was a high possibility that the emission was a remnant of a hypernova exploded some 2-3 million years ago.

• In 2012, MAXI is operating nominally. 58)

• In 2011, MAXI is operating nominally. MAXI monitors the X-ray (0.5 keV-3 keV) variability once every 96 minutes for more than 1,000 X-ray sources covering the entire sky. 59)

- The sky observed in the X-ray spectrum is very different from that observed in visible light. In the night sky seen in visible light, numerous stars are distributed almost evenly – except for the Milky Way – and always shine in the same way. In contrast, strong cosmic X-ray sources are few in number and most of them vary violently. 60)

- Most black hole binaries are "X-ray nova" that emit X-rays only for a few months, and not for most of their life. There are various kinds of nova. Some become active every few years while others show only one activity over the 40-year X-ray observation history. Since MAXI is the most sensitive all-sky monitor to date, it can detect promptly the emergence of new X-ray nova and notify the world, eventually leading to detailed observation from the beginning. MAXI has another feature in that it can monitor changes in X-ray intensity and spectrum by tracking X-ray nova outbursts lasting several months from onset to extinction.

- In addition to these black hole binaries, MAXI has achieved many interesting observations including: detection of the largest flare from active galactic nuclei in X-ray observation history; discovery of a new binary X-ray pulsar, MAXI J1409-619; and detection of a number of intense star flares.

• In Oct. 2010, a new X-ray emitting object in the Milky Way has been observed by MAXI. In the period Oct. 12-17, the MAXI science team noticed the brightening of a new X-ray source in the constellation Centaurus. The Swift spacecraft of NASA was informed by these developments and began immediately observations of the newly found X-ray source. The Swift observation suggests that this source is probably a neutron star or a black hole with a massive companion star located at a distance of a few tens of thousands of light years from Earth in the Milky Way. The object has been named MAXI J1409-619. 61)


Figure 32: The X-ray nova MAXI J1409-619, as observed by the MAXI instrument aboard the ISS (image credit: JAXA/RIKEN/MAXI team)

• On Sept. 25, 2010, the MAXI science team announced that an uncatalogued X-ray source (a short-lived nova) was discovered in the the constellation Ophiuchus. The nova was named “MAXI J1659-152”. 62)

• On August 15, 2009, MAXI has successfully captured the First Light images. 63)

• Initial function checkout of MAXI began on Aug. 3, 2009 (activation of each component, data communication functions, star tracking functions). The initial function test on MAXI will continue for the following three months (Ref. 47).



Launch of HTV-2 (Kounotori-2):

The HTV-2 (H-II Transfer Vehicle-2) of JAXA was launched by the H-IIB vehicle on January 22, 2011 from TNSC. HTV-2 was nicknamed Kounotori 2 (White Stork). 64) 65)

This was the second Japanese service flight to the ISS with a payload (a mixture of pressurized and unpressurized cargo), the total cargo mass is ~ 5,300 kg (16,061 kg of HTV-2 liftoff mass). On Jan. 27, 2011, Kounotori 2 arrived at the ISS (automatic rendezvous) and was successfully grappled by the ISS crew via the SSRMS (Space Station Remote Manipulator System), or Canadarm-2, ahead of berthing to Node-2 Nadir. Both the FHRC and CTC-4 were transferred from Kounotori 2's EP to the space station's ELC-4 using the ISS's SPDM "Dextre". The operations marked Dextre’s first scheduled task since the robot was commissioned in December 2010. 66)


Figure 33: Photo of the HTV-2 arrival at the ISS with the extended Canadarm-2 (image credit: NASA)

On March 28, 2011 HTV-2 was undocked from the ISS for reentry into the Pacific Ocean. Onboard of HTV-2 was the REBR (Reentry Breakup Recorder), an instrument designed and constructed by engineers at The Aerospace Corporation (El Segundo, CA). It successfully collected data during the breakup of the HTV2 vehicle and "phoned home" that data as it fell into the ocean on March 30, 2011. The REBR is a small autonomous device that is designed to record temperature, acceleration, rotation rate, and other data as a spacecraft reenters Earth's atmosphere. The REBR test was coordinated by the U.S. STP (Space Test Program) of DoD. 67)


Figure 34: Overview of the HTV-2 payloads

HTV-2 delivered 5,300 kg of cargo and supplies to the ISS which included: 68)

• Potable water, cargo transfer bags containing food and experiment samples, and JAXA’s two science racks, KOBAIRO Rack and the MSPR (Multi-purpose Small Payload Rack), aboard the HTV-2 PLC (Pressurized Logistics Carrier)

• Two unpressurized ORUs (Orbital Replacement Units) of NASA, namely the the CTC (Cargo Transport Container) and the FHRC (Flex Hose Rotary Coupler). The CTC and the FHRC are using the HTV EP (Exposed Pallet).


Figure 35: Overview of some JEM-EF (Exposed Facility) payloads (image credit: JAXA)



Launch of HTV-3 (Kounotori-3):

JAXA) launched the H-IIB launch vehicle No.3 (H-IIB F3) on July 21, 2012 with theHTV-3 (H-II Transfer Vehicle-3)module onboard , also known as Kounotori-3 (White Stork), a cargo transfer vehicle to the International Space Station). The launch site was the TNSC (Tanegashima Space Center), Japan. 69) 70)


Figure 36: Illustration of the HTV-3 (Kounotori-3) components (image credit: JAXA) 71)

• Berthing to the ISS (scheduled): July 28, 2012

• Orbital parameters: Insertion orbit: 200 km x 300 km (elliptical orbit); Rendezvous with ISS: ~400 km

• The HTV-3 undocked from from the ISS on Sept. 12, 2012 and reentered the atmosphere on Sept. 14. 2012. The 16.5 ton spacecraft carried waste material from the ISS, including used experiment equipment and used clothes. 72)



Figure 37: HTV-3 mating to the H-II rocket (image credit: JAXA)


Payload components of HTV-3:

This represents the second “operational flight” to the ISS. Delivery of about 4600 kg of cargo to the International Space Station. This included internal supplies as well as unpressurized cargo delivered via the ULC (Unpressurized Logistics Carrier). The PLC (Pressurized Logistics Carrier) cargo is comprised of system equipment (61%), science hardware (20%), crew food (15%) and personal crew items (4%). The unpiloted HTV-3 carries eight HTV Resupply Racks that are filled with CTBs (Cargo Transfer Bags). Two spare parts for the Kibo Laboratory of the Space Station are part of HTV’s cargo: one WPA (Water Pump Assembly) an ORU (Orbital Replacement Unit) catalytic reactor of NASA, and CWCP (Cooling Water Circulation Pump). Both of these units are needed for maintenance of the Kibo Laboratory. 73) 74)

Cargo loaded in the PLC (Pressurized Logistics Carrier):

• Food, commodities necessary for the ISS crew.

AQH (Aquatic Habitat) experiment of Japan: AQH houses small fresh water fish. They will be monitored for several generations as they grow and adept to the space environment to understand the changes that occur in these small, model vertebrates. The payload includes two transparent aquariums that have been specially designed for the microgravity environment. It includes environmental control systems as well as camera equipment to monitor the fish. The camera equipment consists of standard still cameras and infrared imagers. AQH will start actual science operations in 2013 with a study looking at skeletal changes of fish grown in microgravity.


Figure 38: Photo of the Aquatic Habitat (image credit: NASA)

AQH is an experimental device to be mounted on the WV (Work Volume) (width 900 mm x depth 700 mm x height 600 mm) in the MSPR (Multi-purpose Small Payload Rack). The AQH can accommodate small fish, such as Medaka (Oryzias latipes) and zebrafish, for up to 90 days.Management of the breeding environment, feeding, observation of water tanks and data monitoring are all automatic. In addition, crew members can make microscopic observations, including collecting biological samples, chemical fixation, freezing and embryonic development. 75)

Mass of AQH

75 kg at launch


Height approx. 600 mm x Width 900 mm x Depth 700 mm

Breeding tank’s inside dimension

150 mm x 70 mm x 70 mm

Breeding water temperature

25 - 30ºC (can be controlled to within ±1ºC)

Water quality maintenance

NH4/NO2 removal by a bacteria filter (nitrobacteria attached), removal of nitric acid by water exchange, solid waste removal and organic matter absorption by a physical filter (filter fabric and activated carbon)

Power consumption

180 W (max)

Service life

5 years (5 experiments, each as long as 90 days, can be conducted once a year)

Controlled from the ground

Water temperature, water flow rate, day/night cycle control by LED lighting, feeding control and CCD camera control

Table 6: Main specifications of the Aquatic Hibitat


J-SSOD (JEM-Small Satellite Orbital Deployer): On the station, only Kibo is equipped with an airlock and arm. The J-SSOD and five small satellites (CubeSats) are part of HTV-3. The objective is to validate the technology and see whether the small satellites can be released without spacewalks. J-SSOD is capable of deploying CubeSats (1U to 3U form factor) as well as small satellites (of size 30 cm-50 cm) into the space.Using this method, satellites contained in bags will be launched and oscillations during launches will be eased, facilitating future satellite design. 76)

J-SSOD consists of mainly three components as shown in Figure 39; the satellite install case, the separation mechanism, and the electrical box. The electrical box controls two sets of separation mechanism in series.


Figure 39: Components of the J-SSOD (image credit: JAXA)

The satellite install case, as shown in the Figure 40, consists of one main spring, the back plate, and the hinged spring door. When the small satellites are installed in this case, the spring is compressed all the way inside the case, and the separation mechanism is used to maintain the satellites inside the case by holding the door hook on the hinged spring door of the satellite install case as shown in the Figure 41.


Figure 40: Illustration of the satellite install case (image credit: JAXA)


Figure 41: Mechanism of holding the small satellite in the case (image credit: JAXA)

The electrical box is used to drive the separation mechanism to rotate the cam, which holds the door hook. As the cam rotates, the door hook is released and the spring hinged door opens. Then, the satellites are pushed out from the satellite install case using the main spring force. The deployment direction is controlled by guide rails in the satellite install case and the rails on the small satellite.

The separation mechanism and the electronics box are intended to be re-used on-orbit. An empty satellite install case can be re-used. In this case, the new satellite needs to be installed by an onboard crew member using the OSE (Satellite Handling Tool) into the satellite install case.

The satellite install case has no heater; it is covered with MLI (Multi-Layer Insulation) providing passive thermal control. All the other components have their own build-in heaters, they are also covered with MLI.


Figure 42: Artist's view of the J-SSOD on the JEMRMS (JEM Remote Manipulator System) releasing CubeSats (image credit: JAXA)

CubeSats: Five CubeSats are part of the HTV-3 payload. The are planned to be deployed by the Japanese Robotic Arm later in 2012. The CubeSats are:

- RAIKO; a 2U CubeSat of Tohoku and Wakayama Universities, Japan

- FITSAT-1; a 1U CubeSat of FIT (Fukuoka Institute of Technology)

- WE WISH (World Environmental Watching & Investigation from Space Height); a 1U CubeSat of Meisei Electric Company, Japan

- F-1; a 1U CubeSat of FTP University, Hanoi, Vietnam

- TechEdSat; a 1U CubeSat of San Jose State University, CA, USA.

The five CubeSats were deployed successfully on Oct. 4, 2012. The deployment of the satellites was performed by corroborative work with Japanese astronaut Hoshide and JAXA flight control team at Tsukuba Space Center. The J-SSOD, which is installed on MPEP (Multi-Purpose Experiment Platform), was extended outboard by Japanese astronaut Hoshide using JEM AL for its retrieval operation using JEMRMS from the ground. After maneuvering JEMRMS to the satellite deployment position by ground control, the first set of the small satellites were deployed by Japanese astronaut Hoshide. Then the second set of the small satellites were deployed from the ground. 77)

The CubeSats will be described in separate files when sufficient documentation is available.


Figure 43: Photo of the CubeSats flown to the ISS on HTV-3 (image credit: Koumei Shibata)

iBall (Reentry Data Recorder), a spherical sensor assembly of JAXA: The objective of iBall is to acquire continuous position, acceleration, temperature, and imagery data during the reentry phase of the HTV-3 vehicle. iBall is installed to hatch closure, onto a surface panel of an HRR (HTV Resupply Rack). During and after the HTV-3 atmospheric reentry, iBall automatically collects data and sends it to the ground for processing in order to more thoroughly understand the processes and characteristics regarding spacecraft reentry.

The device is spherical in shape, has a diameter of 40 cm and includes two cameras that are expected to acquire footage of HTV’S fiery return to Earth and give insight in the destructive reentry environment. The data recorder was developed by IHI Aerospace Co. Ltd.; it has a total mass of 15.5 kg. In the atmosphere, iBall will fall down with a parachute after withstanding high heat with ablator and send data after splashdown via an Iridium satellite. Although iBall will stay afloat for a while for data transmission, it will sink in the water eventually and will not be recovered.

REBR (Reentry Breakup Recorder) - a second recorder developed by the Aerospace Corporation of ElSegundo, CA . REBR records data regarding the thermal, acceleration, rotational and other stresses the vehicle experiences during its destructive re-entry process. This data is used to improve reentry simulation models that show inaccuracies for the peak heating environment of reentry. REBR has a mass of about 4 kg and is 31 cm in diameter.


Figure 44: Photo of the REBR device (image credit: The Aerospace Corporation)

ISERV (ISS SERVIR Environmental Research and Visualization): A new Earth observation payload for the US Segment is also aboard HTV-3. The ISERV payload will further improve Earth observation techniques in support of environmental management, humanitarian assistance and disaster assessment. The project is managed by NASA and USAID (U.S. Agency for International Development). It will operate from the WORF (Window Observation Facility) in the US Destiny Laboratory.

Note: ISERV is described in the “ISS Utilization: WORF” file on the eoPortal.


Cargo loaded in the ULC (Unpressurized Logistics Carrier):

SCaN (Space Communications and Navigation) testbed, designed and developed at NASA/GRC. SCaN is planned to be active aboard the ISS for about a year. The three SCaN devices provide a testbed for the development of SDR (Software Defined Radio) technology. The functions performed by the three radios include communication with the TDRS (Tracking and Data Relay Satellite) system in both S-band and Ka-band, receive GPS (Global Positioning Satellite) signals, and enable proximity communications between the ISS and approaching vehicles.

Note: SCaN is described in the separate “ISS Utilization: SCaN” file on the eoPortal.


MCE (Multi-mission Consolidated Equipment) of JAXA:

MCE of the ULC on HTV-3 is a payload of the JEM-EF (Exposed Facility).The MCE consists of five small mission payloads dedicated to science and technology demonstrations. These investigation payloads include two atmospheric observation investigations that study lightening and resonant scattering from plasma and airglow. 78) 79)

• ISS-IMAP: ISS Ionosphere, Mesosphere, upper Atmosphere, and Plasmasphere mapper. The IMAP payload is a visible light spectrometer that examines the energy and plasma activity and related global transportation near the rim of atmosphere.

• JEM-GLISM (Global Lightning and Sprite Measurement). GLISM looks at the spatial distribution of lightning and plasma phenomena and their discharge characteristics throughout the atmosphere during night passes.

• SIMPLE, REXJ and HDTV are three on-orbit technology demonstration payloads.

- SIMPLE (Space Inflatable Membranes Pioneering Long-term Experiments) seeks to collect engineering data in orbit for inflatable space structures

- REXJ (Robot Experiment on JEM) demonstrates realtime ground control of a robotic system by providing validation data during robotic manipulation.

- HDTV (High Definition Television Camera System) is a high resolution TV camera that acquires data for evaluating how long a COTS-HDTV survives in the orbit environment for development of future Space HDRV systems.


Figure 45: Two views of the MCE payload, at the JEM-EF (left), and its components (right) accommodated in the MCE bus (image credit: JAXA)


ISS-IMAP (ISS Ionosphere, Mesosphere, upper Atmosphere, and Plasmasphere mapper)

ISS-IMAP is a joint research project of the following institutions: JAXA, Kyoto University, Tohoku University, the University of Tokyo, Nagoya University, Kyushu University, NICT (National Institute of Information and Communications Technology), National Institute of Polar Research, etc. The objective of ISS-IMAP (or JEM-IMAP) is to observe resonant scattering from plasma and airglow of the Earth's upper atmosphere in the visible-light, infrared, and extreme ultra violet to reveal the flow of the energy and particles in the upper atmosphere. The mission uses two imagers: VISI (Visible-light and infrared spectrum Imager) and EUVI (Extrem Ultraviolet Imager) to observe airglow and plasma resonant light scattering in the Earth's upper atmosphere.

The plasma structures in the Earth’s upper atmosphere disturb radio waves from satellites, such as GPS and communication satellites, and occasionally cause outages of them. ISS-IMAP will observe these disturbances, and reveal their generation mechanisms. It will lead to develop a forecast system of the Earth's upper atmospheric weather.


Figure 46: Schematic view of the ISS-IMAP measurement concept (image credit: JAXA)

ISS-IMAP mission status: 80)

• The IMAP instrumentation was launched on July 21, 2012 aboard the HTV Kounotori-3 and installed to the Exposed Facility (EF) of Kibo. Later, following the initial observation in August, the regular observation was started on October 15. The following initial observation data was obtained on September 25-26, 2012.

• Airglow obtained by VISI on Sept. 25, 2012: This observation of airglow at 762 nm of wavelength by VISI succeeded in capturing the waves of upper atmosphere at an altitude of 95 km, of which were seen at dozens of kilometers of horizontal wavelength (white diagonal lines in orange are waves in Figure 47) These waves are called atmospheric gravity waves.


Figure 47: Illustration of airglow at 782 nm wavelength observed on Sept. 25, 2012 (image credit: JAXA)

• Sept. 28, 2012: Ionic resonant light scattering obtained by EUVI (Figure 48). Radiation of helium ions in the ionosphere was observed at an altitude of 1,000 km and higher. Though the light is very weak, the project confirmed that the ultrasensitive shooting was working. Each edge of the image appears dark due to the imager's sensitivity characteristics.


Figure 48: Resonant light scattering of He+ was obtained by EUVI, observed over near New Zealand on Sept. 28, 2012 (image credit: JAXA)

The VISI and EUVI instruments demonstrated ultrasensitive imaging as designed.The project confirms to be able to observe the "invisible airglow." For the next two years the wide fluctuations of the upper atmosphere and ionosphere will be observed of the entire globe. The project expects that the mission will permit to investigate the causes of climate oscillation of the whole Earth as well as the reception difficulty and deterioration of satellite communication signals and those of the global GPS navigation devices.


JEM-GLIMS (Global Lightning and Sprite Measurement)

The goal of JEM GLIMS is to observe the TLEs (Transient Luminous Events) and lightning discharge, such as sprites and gigantic jets, at high altitude on a global basis. It will characterize the relationship between TLE/lightning and gamma-ray emissions.

JEM-GLIMS was collaboratively developed by Osaka University, Hokkaido University, Kinki University, Stanford University, National Institute of Polar Research, Osaka Prefecture University, Tohoku University, the University of Electro-Communications and JAXA.

The GLIMS sensor devices are:

1) CMOS cameras at 740-830 nm and at 762 nm

2) Photometers at six different wavelengths

3) VHF interferometer from 70 to 100 MHz

4) VLF receiver from 1 to 40 kHz.


Figure 49: View of the CMOS cameras (left) and photometers (right) of the JEM-GLIMS instrument assembly (image credit: JAXA)


JEM-GLIMS stauts:

• JEM-GLIMS was launched to the ISS on July 21, 2012, aboard the H-II Transfer Vehicle (HTV) Kounotori-3 and installed on the Exposed Facility (EF) of Kibo on August 9, 2012. After the installation, JEM-GLIMS successfully obtained its first observation data. 81)

- By doing the just-above observations, a detailed study for the horizontal spatial distribution and temporal development process of lightning and sprites which has been difficult to derive from the on-ground observation data becomes possible. Further, since the just-above observation from space receives little impact from absorption and scattering by the Earth's atmosphere, it is possible to acquire precise data of the luminescence intensity. Initial checkout of each instrument of JEM-GLIMS was completed; and the observation equipment had been verified working normally.


Figure 50: Image data captured by the CMOS camera of a just below event, a lightning that occurred over Malaysia on Nov. 27, 2012 (image credit: JAXA)

Legend to Figure 50: The lightning emissions show a non-uniform, complicated spatial distribution in a lightning area of >20 km. In addition, a strong light of a near-ultraviolet radiation has been detected with a wavelength of 150-280 nm. The light of near-ultraviolet radiation is mostly absorbed by the ozone in the atmosphere and rarely reaches the ISS flying at an altitude of ~400 km. This suggests that a TLE (Transient Luminous Event) must have occurred in the upper atmosphere (Ref. 81).


SIMPLE (Space Inflatable Membrane structures Pioneering Long-term Experiments)

SIMPLE is a space technology validation experimental device complex composed of multiple inflatable demonstration units designed to be suitable for one of the shared experimental installations that constitute a single experimental block attached to the JEM-EF (Exposed Facility). SIMPLE will share one Exposed Facility Unit (EFU) of the facility with four other planned mission devices.


Figure 51: Final configuration of SIMPLE unit (shown in white) and its set-up configuration in MCE (2010), image credit: University of Tokyo


Figure 52: Launch and operational sequences of MCE/SIMPLE (image credit: JAXA, University of Tokyo (Ref. 84)

The objectives of this planned inflatable experiment are:

1) To verify the concepts of space inflatable structures by demonstrating their key technologies

2) To present and demonstrate the applicability of inflatable structures

3) To acquire the technological skills and operating know-how of inflatable structural systems.

The verification of concepts and technologies include those for inflatable extension, pressure retainment, on-orbit rigidization, multiple-cells configuration and inflatable frame configuration. Acquisition of skills and know-how are to be concentrated on high storage efficiency, reliable inflation system, structure/device design, structural identification and long-term space environment operation. Figures 53 and 54 illustrate SIMPLE in deployed configuration, and Figure 55 in the stored for launch) configuration.

SIMPLE is composed of five units, i.e. the Bus Unit (BU), the Power Unit (PU), the Inflatable Extension Mast (IEM), the Inflatable Material Experimental Panel (IMP), and the Inflatable Space Terrarium (IST).


Figure 53: Concept of mission device complex after deployment (BU exterior view), image credit: JAXA


Figure 54: Concept of mission device complex after deployment (BU interior view), image credit: JAXA


Figure 55: Concept of mission device complex in launch configuration (image credit: JAXA)

The BU consists of the mission controller, the mission sensors including the cameras, the system monitors, and the package. The PU provides the electric power to the other four units. The IEM, IMP, and IST are stowed within the compact package in the launch configuration. This package is planned to be fixed to the EFU together with other experimental installations. Once in orbit, the experimental mission sequence starts with the extension of the IEM. This is followed by a series of experiments conducted in the IMP, and the IST, all of which are based on the inflatable space technologies. The minimum success criterion is fulfilled with the extension of the IEM, driven by the inflatable tube system implanted in the multiple stem-type integrated closed section beam.

• The IEM (Inflatable Extension Mast) is the extensible mast that is the advanced model of SPINAR (Space Inflatable Actuated Rod) heritage. SPINAR was used as an extensible antenna to observe the ionosphere in a sounding rocket experiment of JAXA (Sept. 2007) and the first space verification of an inflatable structure in Japan. 82)

The mission of the IEM is to extend the mast to the specified length, to monitor the secular change of the shape and the stiffness, and to verify the long-term survivability. The change in basic characteristics is monitored by using the camera and accelerometer. IEM is equipped with mechanical retraction system which operates after all the experiments are completed.

IMP (Inflatable Material Experimental Panel): The IMP is the deployable panel on which the material available for inflatable structures is attached. The mission of the IMP is on-orbit verification and the monitoring of the secular change of the materials exposed to space. The materials include UV hardening polymer and shape memory polymer. The condition of the exposed material is monitored mainly by the camera.

IST (Inflatable Space Terrarium): The major mission of the IST is to verify the long-term (~six months) retainment of pressurized membrane structure. Such pressurized membrane structures which can produce pseudo-atmospheric environment on orbit are called Space Terrarium. 83)


500 mm (W) x 300 mm (D) x 500 mm (H) + 500 mm (W) x 200 mm (D) x 300 mm (H)

Instrument mass, power

50 kg, 60 W (typical), 90 W (max), 50 W (standby), 28 VDC x 1 channel

Data rate

5 kbit/s


500 mm x 500 mm x 2000 mm (IEM is extended during mission)

Direction of deployment

-X direction (opposite to the flight path of ISS)


Tolerant to:
1. Launch level of H-IIB/HTV
2. 0.2G in arbitrary direction on JEM-EF (Exposed Facility)

Thermal control

Combination of active control by heater and passive control

Mission life

2-3 years

Table 7: Main parameters of the SIMPLE payload


Figure 56: Main dimensions of SIMPLE (image credit: JAXA)


IST (Inflatable Space Terrarium):

The IST experiment aims to verify reliable deployment and retainment of inner biological environments (pressure and temperature). Two kinds of membrane materials are used for the IST. One provides structural strength against tension force due to high differential pressure and the other provides air-tightness. A multi-layer membrane material, developed for stratospheric platform18, is used as the former material. This material has a multi-layered structure (polyurethane/EVOH/high-strength chemical fabric/polyurethane) with high rupture strength (34kgf/m) and low air-tightness (243 cm3/(m2·24 hr atm) for He). Inside of this material, airtight material such as aluminum laminated film is used for additional air-tightness.

Pressure, temperature

0.9 ±0.1 atm, 20 ± 15ºC (on/off control of halogen lamp)




Use of an on-board camera


74 mm diameter x 240 mm length

Table 8: Parameters of the IST instrument


Figure 57: Illustration of the IST instrument (image credit: Kyoto University, JAXA)

The goal is to realize a leak-proof container and basically no active control of inner pressure is used. The inner temperature is controlled by an on/off on-board halogen light with feedback of the monitored temperature. The IST is equipped with a basic germination device shown in Figure 58. Three kinds of seeds, spinach, tomato, and bird’s-foot trefoil, are set up in foam material. After monitoring the inner pressure and temperature for six months, the project plans to issue a command to break the water supply bag; this will result in water absorption by the ceramic base. The condition of the germination device is monitored by the inner camera. Figure 58 (left) shows an image from an onboard camera.

The structural performance of the IST instrumentation was verified in a ground test on the EM of IST - demonstrating deployment, and conducting pressure and leak tests.


Figure 58: Illustration of the germination device (left: image from the on-board camera) and right: germination test on ground (image credit: JAXA)


Mission status of SIMPLE:

• June 2013: The major outcome that is obtained from the project so far is the proof of practical usefulness of the space inflatable structures. The demonstration of IEM extension showed the robustness of the simple system without any mechanical driving devices. The stiffness of the mast which is monitored through the passive structural vibration frequencies shows no signs of degradation for over 7month in orbit. The IMP demonstrated the effectiveness of shape memory polymers and UV curing polymers that are coupled with deployable components. The IST, though the gas leak took place, demonstrated the compactness of extendable pressure vessels. The seeds that are planted inside the IST are still expected to be subsisting, and the chances of their germination triggered by the moisturization are still sought. 84) 85) 86) 87)

It is worth mentioning that the live images shot by the JEM RMS (Remote Manipulator System, KIBOTT) has been and is going to be extremely helpful in conducting the present experiments. The limited number of image sources with limited telemetry capacity was greatly amended by these live images. The still frame images cut from the live camera of JEM RMS are shown in Figure 59.


Figure 59: IEM during the extension process (left) and IMP overall view of the deployed panel (right), image credit: JAXA, University of Tokyo (Ref. 84)

The minimum mission success criteria of SIMPLE were to conduct the data acquisition during the extension and to attain the minimum 900 mm extension of the IEM, in order to verify its functions and to realize the stiffness characteristics evaluation. The extension mast was set to be the major component within the current inflatable experiments. The final extension was confirmed and the minimum success has been accomplished.

Criteria of full success were:

- for IEM; (1) to maintain the configuration for 6 months, and (2) to maintain its stiffness within 20% deviation of the predicted value in the same period

- for IST; (3) to contain the internal pressure between 0.8 ~ 1.1 atm and being able to withstand that pressure, and (4) to maintain its configuration for 6 months

- for IMP; (5) to obtain the characteristics data of UV curing resin specimens for 6 months. All except the criterion (3) were accomplished. The containment criterion of IST was unattained due to the imperceptible leak of the internal air. The current pressure of the IST (as of March 2013) is approximately 0.2 atm.

The extra success criteria are essentially to acquire the respective data for 2 years. Thus the total mission period extends at least for this term.

Table 9: Mission succsees criteria (Ref. 84)

• On Aug. 24, 2012, the shape-memory polymers in the exposed environment of IMP (Inflatable Material Experimental Panel) were extended successfully, as one element of the series of the SIMPLE (Space Inflatable Membranes Pioneering Long-term Experiments) series, which had been installed on MCE (Multi-mission Consolidated Equipment). This is the world's first achievement. 88)

- Besides the shape-memory polymers installed to the IMP, ultraviolet curing resins were also on the IMP. The curing was also verified (resins' color changes as they cure). - Shape-memory polymers are the shape-memory and functional materials that use glass-transition phenomenon of high-polymer materials that deform to their original shape induced by glass-transition temperature.

• On August 17, 2012, the IEM (Inflatable Extension Mast), one element of the series of SIMPLE (Space Inflatable Membranes Pioneering Long-term Experiments), which realizes the highly-rigid linear shape for the first time in the world, has successfully extended.


Figure 60: IEM extension photographed by the Kibo's RMS (Remote Manipulator System), image credit: JAXA)

• SIMPLE was launched on HTV-2 on July 21, 2012, and was docked to the ISS on July 28, 2012.


REXJ (Robot Experiment on JEM)

A unique space robot has been developed to support astronauts’ EVA (Extravehicular Activity) operations. The robot can move around the surface of a space facility, e.g. a space station using tethers and an extendable robot arm. The robot’s body is as small as microwave oven while it can theoretically move around the space station. Usefulness of the robot system will be demonstrated on the ISS/JEM (International Space Station Japanese Experiment Module). 89) 90) 91) 92) 93)

The Space Robotics Group of JAXA has designed and developed a technological experiment of an Astrobot, named REXJ (Robot Experiment on JEM). An astrobot is an an “intelligent” tool capable of helping astronauts in conducting their work. The technologies needed to realize the astrobots are such as a locomotion capability and a manipulation capability are needed.

Astrobots must be able to move around the space structures such as the space station like an astronaut. REXJ is equipped with tethers. Figure 61 depicts the principle of the robot’s locomotion.

1) The robot has several tethers inside the robot body. Tethers are wound in reels. Each tether has a hook-like mechanism to attach the tether to a structure, such as a handrail, which is prepared for astronauts.

2) Robots have an extendable robot arm. The robot arm has a robot hand at its end.

3) The extendable robot arm can grasp the tether hook and extend the tether.

4) It attaches the tether hook to a handrail or secures itself by some other means.

5) Retract the robot arm and grasp the other tether hook.

6) Connect other tethers to other points.

7) Adjust the length of each tether. This involves a location change of the robot.

8) The area in which the robot can move depends on the number of tethers attached to the structure and the location of each tether anchoring point. Using three tethers, the area in which the robot can move is a triangular plane made by three tether-anchoring points. The area in which the robot can move becomes a three-dimensional space if the number of tether-anchoring points is four or greater.

9) If necessary, change locations of the tethers’ hooks can be done using the extendable robot arm. Then the area or space in which the robot can move can be changed.


Figure 61: Principle of robot locomotion (image credit: JAXA)

This method presents many advantages in comparison to the inchworm and flight methods. The robot is anchored to the space facility by several tethers. Therefore, there is no danger of losing the robot. A similar experiment (Charlotte) was conducted on the space shuttle (STS-63) in 1995. A major difference between the REXJ and the Charlotte is that REXJ robot can decide the area in which the robot will move because tethers are attached to nearby handrails, whereas Charlotte’s tethers had to be attached to nearby structures by the astronaut.

A team of JAXA, THK Co., KEIO University, and the Tokyo Institute of Technology is developing a robot hand that will have the grasping power and dexterity of an astronaut in an EVA environment. The hand will have several fingers to grasp and operate a Pistol Grip Tool. Actuators to drive fingers are mounted inside the finger. All functions necessary to drive the hand such as actuators and control electronics must be installed inside the hand itself. This hand is exchangeable from its wrist.


Figure 62: Photo of the JAXA-THK hand (image credit: JAXA)

The REXJ assembly consists of an extensible robot arm, named SRA (STEM Robot Arm), a robot hand, tethers, and the robot bus control subsystem. STEM (Storable Tubular Extendible Member) is a lightweight fixture with a high degree of retractability. The robot can move by hooking several tethered hooks onto the handrails. This moving method can allow the robot to move in wider area without any special foothold but with existing handling point including handrail for astronauts. 94)


Mission objectives

IMAP (Ionosphere, Mesosphere, upper Atmosphere, and Plasmasphere mapping)

Observe plasma and air disturbance by shooting the invisible lights occurring in between the border of the atmosphere and space using an ultra-sensitive camera

GLIMS (Global Lightning and Sprite Measurement Mission)

Observe the lightning discharge and luminous phenomenon such as sprites, blue jets, and Elves above the thunder cloud.

SIMPLE (Space Inflatable Membranes Pioneering Long-term Experiments)

Operate the inflatable structure for a long period and verify its practicality under the space environment. And collect the basic data for the future structures in space.

REXJ (Robot Experiment on JEM)

Study the special migration technique for the EVA Support Robot in support of the EVA Crew

HDTV (High Definition Television)

To verify the COTS (Commercial-off-the-Shelf) HDTV function under the space environment

Table 10: Overview of the MCE payloads


Figure 63: Illustration of the MCEBus with a schematic view of the REXJ payload (image credit: JAXA)


Figure 64: Overview of the REXJ experiment (image credit: JAXA)

The functional design requirements of the SRA (STEM Robot Arm) call for the following characteristics:

1) It must be able to be extended and retracted many times providing a high degree of position accuracy

2) It must have a suitable stiffness and the potential of carrying the tethered hook.

3) It must provide electrical power and signal wires to interface the robot hand, a fixture of the robot arm, to the bus system.


Figure 65: Illustration of the tether moving method (image credit: JAXA)

The robot can move by executing the following steps:

• Step 1: Hold tethered hook by the robot hand at the end of the extendible robot arm.

• Step 2: Extend the robot arm with the tethered hook to the handrail.

• Step 3: The tethered hook catches the handrail.

• Step 4: Adjust the length of the tether to move the robot body between the handrails.

The robot can move continuously by repeating the above steps. Increasing the number of tethers, providing a larger operational area to be covered by the robot. The robot my also be used to control attitude.

The robot can work more effectively if its arm can extend the tethered hand as far out as possible. However, this scheme causes disadvantages in terms of increasing mass and volume and a decrease in stiffness of the extendible robot arm. Therefore, in the design of the long extendible lightweight robot arm, the availability of a higher degree of retractability along with sufficient stiffness is the preferred solution. As a consequence, the project selected the STEM (Storable Tubular Extendible Member) implementation as the extendible robot arm.

The SRA (STEM Robot Arm) system consists of the STEM extension and retraction mechanism, a driving motor and a flat cable. The mechanism is composed of STEM booms, reels and driving gears. Two motors are used for driving each extension reel and retraction reel individually via driving gears.

Flat cables are installed inside of the STEM booms to interface robot hand equipped on tip of robot arm to the REXJ bus system for engaging communication and for the supply of electrical power. The SRA assembly has a size of 300 mm x 170 mm x 100 mm in launch configuration. The STEM arm (boom) can be extended to a maximum length of 1300 mm. The total mass is 3.5 kg.


Figure 66: Illustration of the SRA assembly (image credit: JAXA)

The SZEM boom consists of one ply of cloth CFRP (Carbon Fiber Reinforce Plastics) covered with Kapton film to prevent crack growth in the CFRP material. There are the sprocket holes on the both side edges of the STEM. A Bi-STEM configuration (tubular shape) is used for better stiffness of the system. The STEM boom is extended using the sprocket drive mechanism ( the sprocket reel pulls the STEM from reel).

Mission status of REXJ:

• In the period August 20 to October 31, 2012, an operational checkout was performed for the Robot Experiment on JEM (REXJ), as one of the MCE (Multi-mission Consolidated Equipment) mission experiments. MCE is installed on the Exposed Facility (EF) of Kibo, the Japanese Experiment Module. JAXA confirmed that the robot's basic function, is properly working during the checkout performed. The functional checkout consisted of: Image photographing by a small camera, extending & retracting of an extendable robot arm, open & close of a hand, wrist joint movement, rotating upper part of the body, and functional checkout of macro command. 95) 96)

The REX-J demonstration is planned for about 6 months from mid October 2012 to March 2013, to test the element technology inevitable for the tether-controlled robot locomotion.

• JEM-REXJ was launched to the ISS on July 21, 2012, aboard the H-II Transfer Vehicle (HTV) Kounotori-3 and installed on the Exposed Facility (EF) of Kibo on August 9, 2012.


HDTV (High Definition Television) camera of MCE:

HDTV is a JAXA developed standard system to transfer HDTV imagery from the ISS to the ground. With this system, a real-time downlink of the HDTV imagery is established.



Launch of HTV-4 (Kounotori-4):

The HTV-4 (H-II Transfer Vehicle-4) of JAXA, nicknamed Kounotori 4 (White Stork), was launched on August 3, 2013 (19:48 hr UTC) on the H-IIB 304 vehicle of Mitsubishi from TNSC (Tanegashima Space Center), Japan. HTV-4 is the fourth cargo transfer vehicle of JAXA to the ISS (International Space Station). After about 15 minutes into the flight, the separation of the HTV-4 vehicle was confirmed. 97) 98) 99) 100) 101) 102)

The HTV-4 development was completed through the experience of the previous HTV-1 to-3 flights. The objective of the HTV-4 is to maintain safe and stable mission operations throughout all mission phases.

The HTV-4 (Kounotori) delivers a total of ~5400 kg of dry cargo, water, experiments and spare parts to the ISS (International Space Station). HTV-4 will be captured by the Canadarm-2 and berthed to the Harmony module. The launch mass of HTV-4 is ~16,000 kg.

The secondary payloads on this flight are:

• TechEdSat-3, a 3U CubeSat of NASA/ARC (Ames Research Center). TechEdSat-3 will fly an Exo-Brake to orbit that is deployed once the satellite is released to demonstrate a PDOS (Passive De-Orbit System) for satellites.

• Pico Dragon, a 1U CubeSat of VNSC (Vietnam National Center) developed by young engineers of the University of Tokyo and IHI Aerospace. The objective of Pico Dragon is to test out a small satellite bus and associated equipment including power generation and distribution, command handling, stabilization and communication systems. The satellite carries a high resolution camera to take photos of Earth that will be downlinked to ground stations. 103)

• ArduSat-1, a 1U CubeSat of NanoSatisfi Inc., San Francisco, CA, USA. The two small satellites will provide a platform which may be used by students or space enthusiasts to run their own space-based Arduino experiments. NanoSatisfi is a small San Francisco based company that offers a special ArduSat educational kit for US $50 and sells three days of operating time on board of its satellites for US $125. Experiment time of two weeks will cost US $450.

• ArduSat-X, a 1U CubeSat of NanoSatisfi Inc., San Francisco, CA, USA.

Note: Arduino refers to an open-source electronics platform or board and the software used to program it. Arduino is designed to make electronics more accessible to users and anyone interested in creating interactive objects or environments. The Arduino processors can sample data from the vehicle's imaging payloads, 1.3 Mpixel cameras, or from any of the various sensors installed in the spacecraft including a photolux sensor, IR temperature sensors, printed circuit board temperature sensors, a 3-axis magnetometer, a Geiger counter, a 6-DOF (Degree of Freedom) IMU (Inertial Measurement Unit, and MEMS gyroscopes.


Figure 67: Photo of the ArduSat Edu kit (image credit: NanoSatisfi)

The four CubeSats onboard HTV-4 will be deployed from the ISS by the J-SSOD (JEM Small Satellite Orbital Deployer) on Kibo between October 2013 and March 2014.



Figure 68: Photo of Kounotori 4 payload module (image credit: JAXA)


Payload components/experiments of HTV-4:

PLC (Pressurized Logistics Carrier): The PLC contains 3,900 kg of cargo. Each supply is packed in the CTBs (Cargo Transfer Bags) respectively, and the bags are stored in the HTV Resupply Racks (HRRs) or strapped to the surface of HRRs. The main cargo includes the following: 104)

1) Experiment samples to be conducted on the JEM (Japanese Experiment Module)/Kibo

2) Experiment equipments and system supplies

• FROST (Freezer-Refrigerator of Stirling Cycle): A Stirling cooler that is able to keep under -70ºC. New domestic refrigerants have been developed to keep cold even in a case of power outage.

• ICE Box (ISS Cryogenic Experiment Storage) Box: A cool box made to keep the container cool without the electrical power during a flight to the ISS.

• i-Ball (Reentry Data Recorder): i-Ball, a sphere in shape, has a mass of 22.1 kg (24.9 kg including the container), the i-Ball diameter is 400 mm. The overall objective is to improve the HTV operations. i-Ball includes two cameras that are expected to acquire footage of HTV’s fiery return to Earth and give insight in the destructive reentry environment. Also, the device includes sensors for measuring temperature and accelerations. In addition, i-Ball houses a GPS Transponder to track the device after re-entry during the final stages of its flight. Its final descent is decelerated by a parachute that is deployed before splashdown in the ocean. On landing in the sea i-Ball will stay afloat for data transmission but will eventually sink. The data recorder was developed by IHI Aerospace Co. Ltd. of Tokyo with a total mass of 15.5 kg.

i-Ball made its first flight on HTV-3 and successfully returned data and imagery. For HTV-4, i-Ball will feature the same basic design with improved sensors and data handling.


Figure 69: Photo of the i-Ball device (image credit: JAXA)

• 4 k resolution camera of JAXA. The camera will be used to shoot imagery of Comet ISON in December 2013. The 4 k camera possesses a resolution 4 times higher than current HD cameras on the ISS, and has been specially altered to shoot ISON with more than 8 times the ultra-high sensitivity than the existing cameras.

• Supplies for Kibo and NASA. Among the notable internal items aboard HTV-4 is a small humanoid robot, known as Kirobo(Kibo Robot Project), which, while much smaller than its bigger cousin Robonaut, has the ability to interact with humans via speech. Kirobo will stay aboard the ISS until December 2014 to test human-robot voice interaction in space, prior to being returned to Earth.

• RTOC (RRM On-orbit Transfer Cage) of NASA. RTOC is designed to transfer hardware outside of the space station. Astronauts will mount the ROTC on the sliding table within the Japanese airlock and then install the task board onto the ROTC, giving the Canadian Dextre robot an easy platform from which to retrieve and subsequently install the new hardware. The Phase 2 hardware complement on HTV-4 consists of: 105)

- Two new RRM TBs (Task Boards): TB3 and TB4. TB3 features new hardware to test cryogen replenishment, which includes five brand new adapters for the RRM MFT (Multi Function Tool). TB3 and TB4 will be transferred outside the ISS via a new piece of hardware also launching on HTV-4, called the ROTC (RRM On-orbit Transfer Cage).

- The RTOC (RRM On-orbit Transfer Cage): an original device developed by SSCO (Satellite Servicing Capabilities Office) of NASA/GSFC to transfer hardware outside of the International Space Station.


Figure 70: Phase 2 RRM task bords, task bord 3 (left), task board 4 (right), image credit: NASA


Figure 71: Photo of the RTOC during launch preparations at NASA/GSFC (image credit: NASA)

3) Food (retort pouches, dried food, snacks, beverages), drinking water. This is the second time for HTV to deliver the drinking water. This time, the HTV-4 increased the amount and delivers 480 liter of water.

4) Commodities and clothes for astronauts.

5) The four CubeSats (secondary payloads) are contained within the PLC.


ULC (Unpressurized Logistics Carrier): The HTV ULC carries 1500 kg of ORUs (Orbital Replacement Units) and experiment payload to be installed in the exposed facilities of the ISS.

• MBSU (Main Bus Switching Unit): Four MBSUs will be placed on the S0 truss of the ISS. The MBSU is an important hardware that distributes electric power to each system on the ISS. The objective is to provide spare devices in case of a failure. Astronauts Akihiko Hoshide and Sunita Williams exchanged one of the MBSUs during EVA between August to September in 2012.

• UTA (Utility Transfer Assembly): The UTA is one of the ORUs (Orbital Replacement Units) that is placed on the SARJ (Solar Array Rotary Joint) and provides power and data interface to the P3-P4 and S3-S4 trusses. The SARJ rotates the entire outboard truss segments to allow the solar arrays to track the sun. The individual wings are rotated via Beta Gimbal Assemblies.

• NASA's payload STP-H4 (Space Test Program - Houston 4)


Figure 72: Photo of the cargo layout on the EP-MP (Exposed Pallet - Multi-Purpose), image credit: JAXA, NASA


ATOTIE-mini (Advanced Technology On-orbit Test Instrument for space Environment - mini)

The HTV surface electrical potential information has been evaluated by analysis. However, the ISS project requested an investigation of the effect against the ISS electrical potential at HTV docking. - The ISS adopts solar power, and the current is generated with a voltage of 160 V. The PCU (Plasma Contactor Unit) disperses the electrical charge and keeps the ISS about the same with the surrounding plasma environment. Under such an environment, it is important to know how the electric potential changes when the HTV, which operates at 50 V, is berthed to the ISS. To make an attempt to clarify this, one surplus solar array panel was replaced with a surface potential sensor panel on the body of the HTV4 (Figure 73). 106)

To clarify this, one solar array panel has been removed to install a surface potential sensor panel on the body of the HTV-4.


Figure 73: Accommodation of the ATOTIE-mini experiment on the HTV-4 to measure the surface potential (image credit: JAXA, NASA)


STP-H4 (Space Test Program - Houston 4)

The STP-H4 is an ELC-1 (Express Logistics Carrier-1) payload complement consisting of 5 DoD experiments and 3 reimbursable NASA experiments. The payload performs atmospheric observation, thermal control experiment, radiation measurement, data processing module testing, and phenomenon observation caused by lightning and others. NASA's Space Test Program is dedicated to fly small payloads loaded with different technical and other demonstrations to space for assessments in the space environment.

Three of the DoD payloads were developed and built at NRL (Naval Research Laboratory). The Spacecraft Engineering Department, also part of NRL's NCST (Naval Center for Space Technology), provided the flight harness for the STP-H4 platform and the Power Control Electronics Box for STP-H4. The NRL instruments are: 107) 108)

SWATS (Small Wind And Temperature Spectrometer) of NRL (Naval Research Laboratory), a space weather instrument.

- SWATS acquires simultaneous collocated, in situ measurements of atmospheric density, composition, temperature and winds. These data will support improvements to the thermospheric/ionospheric density and wind models to improve orbit determination and prediction.

- iMESA-R (Integrated Miniaturized Electrostatic Analyzer-Reflight) of USAFA (United States Air Force Academy ), Colorado Springs, CO, is integrated into SWATS, enabling synergistic collocated density and temperature measurements between the instruments.

GLADIS (Global Awareness Data-Exfiltration International Satellite Constellation Concept) demonstrator of NRL, Washington D.C. The objective is to test and validate dual-channel (UHF and VHF) interference mitigation (antenna design) by receiving the AIS (Automatic Identification System) vessel tracking signal — while simultaneously providing two- way communications to widely distributed Maritime Domain Awareness sensor arrays via ODTML (Ocean Data Telemetry Microsatellite Link). The goal of the demonstration is to verify that these technologies can be used to built a small, low-mass and inexpensive satellite for global awareness purposes.

MARS (Miniature Array of Radiation Sensors) of NRL. MARS consists of an array of sensors that monitor the total dose radiation on the host spacecraft for 3D radiation modeling. NASA/JSC is a co-investigator on MARS, and the MARS experiment includes NASA/JSC provided radiation shielding on some of the MARS sensors.

ATT (Active Thermal Tile) of AFRL. ATT is a quick-insert thermal control device that is modular, reconfigurable, and fully scalable to a wide array of component sizes. ATT is a variable conductance interface that uses a TED (Thermoelectric Device) to modulate heat transfer between two interfaces – typically between a component and the spacecraft bus. The TED operates in three modes: cooling, heating, and off (which is the low conductance insulating mode). The STP-H4-ATT experiment measures the initial on-orbit performance of an ATT string consisting of four tiles to determine the performance relative to ground testing and to anchor the thermal model. In addition, a subset of the initial testing is performed periodically during the 12 months of on-orbit operations to measure any degradation over time caused by the space environment. 109)

ISE 2.0 (ISS SpaceCube Experiment 2.0) of NASA/GSFC. 110) 111)

- SpaceCube2.0: A small, powerful data processing module with multiple HD cameras to demonstrate new algorithms, including RHBS (Radiation Hardened By Software) algorithms and Earth “event detection” algorithms. The goal of the SpaceCube program is to provide 10x to 100x improvements in on-board computing power while lowering relative power consumption and cost. The SpaceCube 2.0 breadboard is coupled with a high-resolution camera system, gamma ray detector, photometer, antenna and thermal plate experiment, with the primary goals of extending SpaceCube “radiation hardened by software” research. 112) 113)

- EHD: A thermal plate prototype to demonstrate Electro Hydro-Dynamic (EHD) pumping of liquids in micro-channels for advanced thermal control.

- FireStation: Measures the optical lightning flash, the radio signatures of lightning, and the gamma rays and electrons produced in terrestrial gamma ray flashes. The objective is to understand the means by which the Earth’s atmosphere, normally a fairly quiet place, occasionally generates very brief but intense flashes of gamma radiation. These TGFs (Terrestrial Gamma-ray Flashes) have been linked to lightning since their discovery in 1994, but there are many open questions about what kinds of lightning produce them, and how they are generated. 114) 115) 116)


Figure 74: Schematic view of the STP-H4 payload (image credit: The Aerospace Corporation) 117)


Figure 75: Illustration of the ISE 2.0 (ISS SpaceCube Experiment 2.0), image credit: NASA


Figure 76: Block diagram of SpaceCube 2.0 (image credit: NASA)

The berthing of HTV-4 occurred on August 9, 2013. HTV-4 was installed on its berthing port on the Earth-facing side of the International Space Station’s Harmony node. 118) 119)

• After HTV-4 has been berthed with the ISS, the EP (with MBSU, UTA and STP-H4 attached) will be extracted from the ULC using the SSRMS, and then maneuvered and handed off to the JEM RMS, whereupon the EP will be temporarily attached to the JEF (Japanese Exposed Facility).

• The Dextre robot will then, one-by-one, remove the cargo from the EP (Exposed Pallet) and robotically install them onto their respective locations outside the ISS, all controlled entirely from the ground.

• The MBSU will be installed onto an empty FRAM on the Express Logistics Carrier-2 (ELC-2), while the UTA will be installed onto an empty FRAM on ELC-4. STP-H4 will be installed onto an empty FRAM on ELC-1, following which Dextre will remove the old STP-H3 experiment from ELC-3, and place it on the EP, with the EP then being removed from the JEF and inserted back into the HTV ULC.

• STP-H3 was launched to the ISS on STS-134 in May 2011, however since the experiment is now completed, it will be disposed of on HTV-4 to make room for future experiments, in the process marking the first time that a HTV has been used to dispose of external cargo.

• In early September, the HTV-4 cargo vehicle will be filled with trash, detached from the station and sent to burn up in Earth's atmosphere over the Pacific Ocean.

• On Sept. 5, 2013, the HTV-4/Kounotori-4 left the ISS and reentered the atmosphere on Sept. 7 at an altitude of 120 km - completing its cargo supply mission (destructive reentry into the Pacific Ocean). 120)

• On Nov. 19, 2013, three CubeSats ( PicoDragon, ArduSat-1 and ArduSat-X) were deployed from the J-SSOD (JEM-Small Satellite Orbital Deployer). JAXA astronaut Koichi Wakata, Expedition 38 flight engineer, monitored the satellite deployment while operating the Japanese robotic arm from inside Kibo. 121)
On Nov. 20, 2013 at 7.:58 UTC, the next deployment took place in which the 3U TechEdSat-3 was released into orbit. 122)

Table 11: Overview of HTV-4 activities at the ISS 118) 119) 120) 121) 122)


Figure 77: Deployment of three CubeSats from the Space Station on Nov. 19, 2013 (image credit: NASA, Ref. 121)



JEM-EUSO (JEM - Extreme Universe Space Observatory)

JEM-EUSO is a science mission, a downward looking experiment from the ISS-JEM, and the first space mission devoted to the exploration of the Universe. The objective is to detect the origin of the EECRs (Extreme Energy Cosmic Rays) above energies of E > 100 EeV (E = Exa = 1018) and to explore the limits of the fundamental physics, through the observations of their arrival directions and energies. 123) 124)


Launch: The JEM-EUSO mission is planned to be launched by a H2B rocket in the timeframe 2016 and be transferred to ISS by the HTV (H-II Transfer Vehicle). It will be attached to the Exposed Facility external experiment platform of “KIBO.”

Background: JEM-EUSO is being developed by an international collaboration of many institutions from 13 countries. The concept of JEM-EUSO was first proposed as a free-flyer, but was selected by ESA (European Space Agency) as a mission attached to the Columbus module of ISS. The Phase-A study for the feasibility of that observatory (hereafter named ESA-EUSO) was successfully completed in July 2004. Nevertheless, because of financial problems in ESA and European countries, together with the logistic uncertainty caused by the Columbia accident, the Phase B was left pending.

In 2006, Japanese and U.S. teams redefined the mission as an observatory to be attached to JEM-ISS. The mission was renamed to JEM-EUSO and started with a renewed Phase-A study. JEM-EUSO is designed to achieve an exposure larger than 1 million km2 sr year at the highest energies. This overwhelmingly high collecting power permits the project to achieve the main scientific objectives: astronomy and astrophysics through the particle channel to identify their sources by arrival direction analysis and to measure their energy spectra from the individual sources. It will constrain acceleration or emission mechanisms of the EECRs, and also finally confirm the GZK (Greisen-Zatsepin-Kuz'min) process for the validation of the Lorentz invariance up to γ~1011.

Science objectives: The science objectives of the JEM-EUSO mission are divided into one main objective and five exploratory objectives. The main objective of JEM-EUSO is to initiate a new field of astronomy that uses the extreme energy particle channel (5 x 1019 eV < E < 1021 eV). JEM-EUSO has the critical exposure of 1 million km2 x sr x year to observe all the sources at least once inside several hundred Mpc (Megaparsec, 1 pc = 3.26 light-years), making possible the following goals:

• Identification of sources with the high statistics by arrival direction analysis

• Measurement of the energy spectra from individual sources to constrain the acceleration or the emission mechanisms.

The five exploratory objectives are:

1) Detection of extreme energy gamma rays

2) Detection of extreme energy neutrinos

3) Study of the Galactic magnetic field

4) Verification of the relativity and the quantum gravity effects at extreme energy

5) Global survey of nightglows, plasma discharges, and lightning.


JEM-EUSO instrument:

The instrument assembly consists of the main telescope, an atmosphere monitoring system, and a calibration system. The main telescope of the JEM-EUSO mission has a large diameter (2.5 m) and a wide FOV (Field of View) of ±30º; its focal plane is an extremely-fast (~µs) and highly-pixelized (~3 x 105 pixels) digital camera. It is sensitive in near-UV wavelength (330-400 nm) with single-photon-counting mode.

The telescope consists of four parts: the optics, the focal surface detector and electronics, and the structure. The optics focuses the incident UV photons onto the focal surface with an angular resolution of 0.1º. The focal surface detector converts the incident photons to photoelectrons and then to electric pulses.

Optics: Two curved double sided Fresnel lenses with 2.65 m external diameter, an intermediate curved precision Fresnel lens, and a pupil constitute the “baseline” optics of the JEM-EUSO telescope. The Fresnel lenses provide a large-aperture, and a wide FOV as well as a low mass and a high UV light transmittance.

The combination of the three Fresnel lenses realizes a full angle FOV of 60º and an angular resolution of 0.1º. This resolution corresponds approximately to (0.75 - 0.87) km on Earth's surface, depending on the location inside the FOV in the nadir pointing mode. The material of the lenses is UV transmitting PMMA (PolyMethyl MethAcrylate) which has a high UV transparency in the wavelength from 330 nm to 400 nm. A precision Fresnel optics adopting a diffractive optics technology is used to suppress the color aberration.


Figure 78: Concept of the JEM-EUSO telescope to detect EECRs (image credit: JEM-EUSO consortium)


1) “Overview of Attached Payload Accommodations and Environments on the International Space Station,” NASA/TP–2007–214768, Sept. 2007, URL:

2) Kazuyoshi Kawasaki, “Overview of JEM-EF on ISS,” JAXA, URL:

3) Yoshiyuki Hasegawa, “Japan's Perspective on the International Space Station for Exploration,” Proceedings of the 64th International Astronautical Congress (IAC 2013), Beijing, China, Sept. 23-27, 2013, paper: IAC-13-B3.1.4

4) H. Oda, D. Tahakashi,T. Yoshinouchi, T. Matsueda, “Kibo Exposed Facility Second Phase Utilization Plan,” Proceedings of the 26th ISTS (International Symposium on Space Technology and Science) , Hamamatsu City, Japan, June 1-8, paper: 2008, 2008-r-1-12


6) Nancy Atkinson, “Japan Launches New Era of ISS Resupply Ships,” Sept. 10, 2009, URL:

7) HTV-1 Mission Press Kit, JAXA, Sept. 9, 2009, Rev. A, URL:

8) “HTV re-entered the atmosphere, mission completed,” JAXA, Nov. 2, 2009, URL:

9) “Attached Payload BUS for Kibo Exposed Facility Payload: APBUS,” JAXA, Feb. 9, 2005, URL:

10) K. Kikuchi, T. Nishibori, K. Mizukoshi, R. Sato, S. Ochiai, “Submillimeter Limb-emission Sounder JEM/SMILES aboard the Space Station,” Proceedings of the 26th ISTS (International Symposium on Space Technology and Science) , Hamamatsu City, Japan, June 1-8, 2008, Paper: 2008-h-10


12) T. Manabe, M. Seta, J. Inatani, R. Satoh, T. Nishibori, T. Miura, H. Ozeki, N. Ikeda, Y. Fujii, K. Kikuchi, Y. Kasai, H. Masuko, SMILES Mission Team, “Development of Superconducting Submillimeter-Wave Limb-Emission Sounder (JEM/SMILES) Aboard the International Space Station for Monitoring Stratospheric Ozone Layer,” URL:

13) SMILES Science and Mission Teams, “JEM/SMILES Mission Plan,” Version 2.1, November 15, 2002, URL:


15) Y. Kasai, J. Mendrok, Ph. Baron, S. Ochiai, T. Manabe, K. Kikuchi, T. Nishibori, T. Sano, D. Murtagh, J. Urban, J. Moller, P. Eriksson, S. Buehler, D. L. Wu,, and the JEM/SMILES Mission Team, “Proceedings of the 5th ESA Workshop on Millimeter Wave Technology and Applications & 31st ESA Antenna Workshop, May 18-20, 2009, Noordwijk, The Netherlands, ESA, WPP-300

16) K. Kikuchi and JEM/SMILES Mission Team, “Introduction to JEM/SMILES,” Workshop on Submillimeter Astronomy and Receiver Technologies Joint Workshop with the 6th Workshop on Submillimeter-Wave Receiver Technologies in Eastern Asia, Dec. 8-10 2005, Nanjing, China,

17) H. Masuko, T. Manabe, M. Seta, Y. Kasai, S. Ochiai, Y. Irimajiri, J. Inatani, N. Ikeda, T. Nishibori, H. Ozeki, R. Sato, Y. Fujii, T. Nakajima, H. Watanabe, K. Kikuchi, M. Koyama, “Superconducting Submillimeter-wave Limb Emission Sounder (SMILES)onboard Japanese Experimental Module (JEM) of International Space Station (ISS),” Proceedings of IGARSS 2000, Honolulu, HI, USA, July 24-28, 2000, Vol. 1, pp. 71-73

18) M. Seta; H. Masuko,T. Manabe, S. Ochiai, Y. Irimajiri, J. Inatani, H. Harada, T. Noguchi, S.-C. Shi, K. Narasaki, Y. Abe, “ Submillimeter-Wave SIS Receiver System for JEM/SMILES,” Advances in Space Research, Volume 26, No 6, 2000 , pp. 1021-1024

19) T. Manabe, T. Fukami, T. Nishibori, K. Mizukoshi, S. Ochiai, “Measurement and Evaluation of Submillimeter-Wave Antenna Quasi-optical Feed System by a Phase-Retrieval Method in the 640-GHz Band,” Special Section on 2007 International Symposium on Antennas and Propagation (ISAP 2007) - Papers - Antennas, August 20-24, 2007, Toki Messe, Niigata, Japan

20) J. Inatani, K. Narasaki, S. Tsunematsu, M. Kyoya, T. Manabe, M. Seta, T. Iida, R. Satoh, “Mechanical Cooler and Cryostat for Submillimeter SIS Mixer Receiver in Space,” 8th International Symposium on Remote Sensing, Toulouse, France, Sept. 17-21, 2001,

21) K. Noguchi, M. Takabayashi, H. Ohmine, J. Inatani, T. Nishibori, “Design of Elliptical Aperture Antenna at Submillimeter Wavelengths for JEM/SMILES,” 21st International Communications Satellite Systems Conference and Exhibit, Yokohama, Japan, Apr. 15-19, 2003, AIAA-2003-2224


23) Public Release of Observation Data of the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) aboard Japanese Experiment Module “KIBO” on the International Space Station,” JAXA, NICT, March 5, 2012, URL:

24) Donal Murtagh, Philippe Baron, “Measurement of stratospheric and mesopheric wind fields using SMILES and with anoutlook to the future,” Proceedings of ATMOS 2012, Advances in Atmospheric Science and Applications, Bruges, Belgium, June 18-22, 2012, URL:

25) Takuki Sano, “Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES),” Space Travel, April 12, 2012, URL:

26) S. Ochiai, Y. Irimajiri, K. Kikuchi, T. Nishibori, T. Sano, R. Sato, T. Manabe, H. Ozeki, M. Shiotani, “Performance verification and calibration of Superconducting Submillimeter-Wave Limb -Emission Sounder (SMILES),” Proceedings of IGARSS (IEEE International Geoscience and Remote Sensing Symposium) 2010, Honolulu, HI, USA, July 25-30, 2010

27) Ken-ichi Kikuchi, Toshiyuki Nishibori, Satoshi Ochiai, Hiroyuki Ozeki, Yoshihisa Irimajiri, Yasuko Kasai, Makoto Koike, Takeshi Manabe, Kazuo Mizukoshi, Yasuhiro Murayama, Tomoo Nagahama, Takuki Sano, Ryota Sato, Masumichi Seta, Chikako Takahashi, Masahiro Takayanagi, Harunobu Masuko, Junji Inatani, Makoto Suzuki, Masato Shiotani, “Overview and early results of the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES),” Journal of Geophysical Research, Vol. 115, Dec. 7, 2010, Issue D23, doi:10.1029/2010JD014379

28) “SHADOZ (Southern Hemisphere Additional Ozonesondes) Notes,” NASA/GSFC Newsletter 11, Nov. 2010, URL:

29) K. Kikuchi, T. Nishibori, S. Ochiai, T. Manabe, H. Ozeki, R. Sato, T. Sano, Y. Irimajiri, M. Shiotani, “Instrument overview and operation of JEM/SMILES,” International Archives of the Photogrammetry, Remote Sensing and Spatial Information Science, Volume XXXVIII, Part 8, Kyoto, Japan, 2010, URL:


31) K. Suzuki, K. Oikawa, K. Arai, K. Imagawa, “Japanese Experiment Module (JEM) Flight 2J/A Assembly Scenario,” 2008-f-10, Proceedings of the 26th ISTS (International Symposium on Space Technology and Science) , Hamamatsu City, Japan, June 1-8, 2008

32) Tateo Goka, Kiyokazu Koga, Haruhisa Matsumoto, Yugo Kimoto, Shohich Ichikawa, Noriko Yamada, Hideyuki Watanabe, Miho Endo, Daichi Sakoh, Tatsuo Matsueda, Takahiro Obara, “Space Environment Measurement outside the International Space Station/Japanese Experimental Module “Kibo” (JEM),” Proceedings of the 27th ISTS (International Symposium on Space Technology and Science) , Tsukuba, Japan, July 5-12, 2009, paper: 2009-r-2-20

33) Masaharu Takata, Masaru Wada, Yasufumi Wakabayashi, “Platform for Robotics Experiments,” Proceedings of 'The 8th International Symposium on Artifical Intelligence, Robotics and Automation in Space, Munich, Germany, Sept. 5-8, 2005, URL:

34) Kiyokazu Koga, Haruhisa Matsumoto, Takahiro Obara, Yugo Kimoto, Noriko Yamada, Hideyuki Watanabe, Miho Endo, Daichi, Sakoh, Tatsuo Matsueda, Tateo Goka, “Space Environment Data Acquisition Equipment - Attached Payload (SEDA-AP)on the International Space Station - Japanese Experimental Module “Kibo” Exposed Facility,” Proceedings of the 60th IAC (International Astronautical Congress), Daejeon, Korea, Oct. 12-16, 2009, IAC-09.D5.3.5

35) “Space Environment Data Acquisition equipment (SEDA-AP),” JAXA, March 30, 2007, URL:

36) “Space Environment Data Acquisition Equipment - Attached Payload (SEDA-AP),”URL:

37) Kiyokazu Koga, Haruhisa Matsumoto, Takahiro Obara, Tateo Goka, Tokonatsu Yamamoto ,Yasushi Muraki, “Development of the neutron monitor onboard Space Environment Data Acquisition Equipment – Attached Payload (SEDA-AP),” Proceedings of the 27th ISTS (International Symposium on Space Technology and Science) , Tsukuba, Japan, July 5-12, 2009, JAXA–SP–09–006, URL:

38) Haruhisa Matsumoto, Kiyokazu Koga , Tateo Goka,Takahiro Obara, “Development of the energetic particle spectrometer onboard Space Environment Data Acquisition Equipment – Attached Payload (SEDA-AP),” Proceedings of the 27th ISTS (International Symposium on Space Technology and Science) , Tsukuba, Japan, July 5-12, 2009, paper: 2009-r-2-22

39) “Space Environment Data Acquisition Equipment - Attached Payload (SEDA-AP),” NASA, April 26, 2013, URL:

40) Kiyokazu Koga, Haruhisa Matsumoto, Tokonatsu Yamamoto, Yasushi Muraki, “Measurement Result of the Neutron Monitor Onboard Space Environment Data Acquisition,” Proceedings of the 29th ISTS (International Symposium on Space Technology and Science), Nagoya-Aichi, Japan, June 2-8, 2013, paper: 2013-r-48

41) “ISS On-Orbit Status 02/04/12,” NASA, Feb. 4, 2012, URL:

42) Tetsuya Honda , Daichi Sakoh, Miho Endo, Koki Oikawa, Tatsuo Matsueda, “KIBO External Payload Utilization Plan Overview,” Proceedings of the 28th ISTS (International Symposium on Space Technology and Science), Okinawa, Japan, June 5-12, 2011, paper: 2011-h-21

43) T. Obara, K. Koga, Y. Kimoto, H. Matsumoto, S. Sasaki, N. Yamada, S. Muraki, T. Doke, T. Goka, “Space Environment Data Acquisition with the Kibo Exposed Facility on the International Space Station (ISS),” Data Science Journal, Volume 8, March 4, 2010

44) K. Koga, T. Goka (PI), H. Matsumoto, T. Obara, Y. Muraki, T. Yamamoto, “Measurement of Neutrons at ISS by the SEDA-AP on-board JEM,” 22nd European Cosmic Ray Symposium in Turku, Finland, August 3-6, 2010, URL:

45) Ryuichi Usui, Mikio Morii, Nobuyuki Kawai, Takayuki Yamamoto, Tatehiro Mihara, Mutsumi Sugizaki, Masaru Matsuoka, Kazuo Hiroi, Masaki Ishikawa, Naoki Isobe, Masashi Kimura, Hiroki Kitayama, Mitsuhiro Kohama, Takanori Matsumura, Satoshi Nakahira, Motoki Nakajima, Hitoshi Negoro, Motoko Serino, Megumi Shidatsu, Tetsuya Sootome, Kousuke Sugimori, Fumitoshi Suwa, Takahiro Toizumi, Hiroshi Tomida, Yoko Tsuboi, Hiroshi Tsunemi, Yoshihiro Ueda, Shiro Ueno, Kazutaka Yamaoka, Kyohei Yamazaki, Atsumasa Yoshida, “Outburst of LS V+44 17 Observed by MAXI and RXTE, and Discovery of a Dip Structure in the Pulse Profile,” Jan. 31, 2012, URL:

46) Tateo Goka, and SEDA-AP Team (Kiyokazu Koga, Haruhisa Matsumoto, Yugo Kimoto, Shohich Ichikawa, Noriko Yamada, Hideyuki Watanabe, Miho Endo, Daichi Sakoh, Tatsuo Matsueda, Takahiro Obara), “Initial Results from the Space Environment Data Acquisition Equipment aboard the International Space Station,” JAXA–SP–09–006, URL:


48) “The world's first discovered extraterrestrial material captured from the ISS,” JAXA, Oct. 26, 2012, URL:


50) S. Ueno, H. Tomida, N. Isobe, H. Katayama, K. Kawasaki, T. Yokota, N. Kuramata, M. Matsuoka, T. Mihara, I. Sakurai, M. Nakajima, M. Kohama, H. Tsunemi, E. Miyata, N. Kawai, J. Kataoka, Y. Serino, Y. Yamamoto, A. Yoshida, H. Negoro, “Development status and performance estimation of MAXI,” Proceedings of SPIE, 'UV and Gamma-Ray Space Telescope Systems,' Vol. 5488, pp. 197-208, 2004

51) Daiki Takahashi, Masaru Matsuoka, Tatsuo Matsueda ,Hiroshi Tomida,Shiro Ueno, Kazuyoshi Kawasaki, Motoko Suzuki, Masaki Ishikawa,Tatehiro Mihara, Mitsuhiro Kohama, Mutsumi Sugizaki,Nobuyuki Kawai, Jun Kataoka, Atsumasa Yoshida, Kazutaka Yamaoka, Hiroshi Tsunemi, Emi Miyata, Yoshihiro Ueda, Satoshi Eguchi,Koji Taguchi, Isao Tanaka, Nobuyuki Kidachi, Hiroshi Takahashi, Hajime Murao, Kenji Yamaguchi, “Monitor of All-sky X-ray Image (MAXI) Mission on the International Space Station,” Proceedings of the 26th ISTS (International Symposium on Space Technology and Science) , Hamamatsu City, Japan, June 1-8, 2008, paper: 2008-h-08, URL:

52) M.Matsuoka, K.Kawasaki, S. Ueno, H.Tomida, M. Kohama, M.Ishikawa, H.Katayama, M.Suzuki, T.Miyakawa, T.Mihara, N.Isobe, H.Tsunemi, E.Miyata, H.Negoro, M.Nakajima, N.Kawai, J.Kataoka, A.Yoshida, K.Yamaoka, M.Morii, “An Overview of MAXI onboard JEM-EF of the International Space Station, Proceedings of the SPIE, 'UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XV', Vol. 6686, pp. 668611-668611-9, Sept. 2007

53) Masaki Ishikawa, Daiki Takahashi, Masaru Matsuoka, Shiro Ueno, Hiroshi Tomida, Haruyoshi Katayama, Kazuyoshi Kawasaki, Mitsuhiro Kohama, Motoko Suzuki, Yasuki Adachi, Tatehiro Mihara, Naoki Isobe, Hiroshi Tsunemi, Emi Miyata, Atsumasa Yoshida, Kazutaka Yamaoka, Nobuyuki Kawai, Jun Kataoka, Motoki Nakajima, Hiroshi Negoro, Mikio Morii, “On-board and Ground Data processing System of MAXI,” Proceedings of the 26th ISTS (International Symposium on Space Technology and Science) , Hamamatsu City, Japan, June 1-8, 2008, paper: 2008-f-04

54) Shiro Ueno, Masaru Matsuoka, Kazuyoshi Kawasaki, Hiroshi Tomida, Yasuki Adachi, Mitsuhiro Kohama,Motoko Suzuki, Masaki Ishikawa, Haruyoshi Katayama, Tatehiro Mihara, Mutsumi Sugizaki, Naoki Isobe, Hiroshi Tsunemi, Emi Miyata, Nobuyuki Kawai, Jun Kataoka, Atsumasa Yoshida, Kazutaka Yamaoka, Hitoshi Negoro, Motoki Nakajima, Mikio Morii, Yoshihiro Ueda, Satoshi Eguchi, and the MAXI team, “The MAXI Mission Overview and Schedule,” URL:

55) T. Mihara, M. Sugizaki, “Monitor of All-Sky X-Ray Image (MAXI) on the International Space Station,” March 7, 2009, URL:

56) H. Katayama, H. Tomida , M. Matsuoka, H. Tsunemi, E. Miyata, D. Kamiyama, N. Nemes, “Performance of the engineering model of the MAXI/SSC,” URL:

57) “MAXI detects a hypernova remnant - the world's first discovery in the Milky Way Galaxy,” JAXA, April 19, 2013, URL:

58) “Monitor of All-sky X-ray Image (MAXI),” NASA, March 23, 2012, URL:

59) Tetsuya Honda , Daichi Sakoh, Miho Endo, Koki Oikawa, Tatsuo Matsueda, “KIBO External Payload Utilization Plan Overview,” Proceedings of the 28th ISTS (International Symposium on Space Technology and Science), Okinawa, Japan, June 5-12, 2011, paper: 2011-h-21

60) Nobuyuki Kawai, “Black Hole Binaries Observed by MAXI,” JAXA/ISAS, July 13, 2011, URL:

61) “Another X-ray Nova Detected by ISS, Swift,” Universe Today, Oct. 25, 2010, URL:

62) “ISS Instrument Detects X-ray Nova,” Univers Today, Oct. 4, 2010, URL:

63) “MAXI successfully captured First Light images,” JAXA, Aug. 18, 2009, URL:

64) “Launch Result of H-IIB Launch Vehicle No. 2 withKounotori 2 (HTV2) Onboard,” JAXA, Jan. 22, 2011, URL:

65) T Aoki, H. Furuya, K. Ishimura, Y. Miyazaki, K. Senda, H. Tsunoda, K. Higuchi, J. Ishizawa, N. Kishimoto, R. Sakai, A. Watanabe, K. Watanabe, “On-Orbit Verification of Space Inflatable Structures,” paper: 2008-c-07, Proceedings of the 26th ISTS (International Symposium on Space Technology and Science), Hamamatsu City, Japan, June 1-8, 2008

66) Ken Kremer, “Japans White Stork Kounotori Grappled and Nested at Space Station: Video,Photo Album,” Universe Today, Jan. 27, 2010, URL:

67) “First REBR Reentry a Success,” The Aerospace Coporation, March 30, 2011, URL:

68) “HTV2 (Kounotori 2) Mission Press Kit,” JAXA, Jan. 20, 2011, URL:

69) “Launch Result of H-IIB Launch Vehicle No. 3 with H-II Transfer Vehicle "KOUNOTORI3" (HTV3) Onboard,” JAXA, July 21, 2012, URL:

70) Steve Cole, Janet Anderson, “Station-Bound Cargo Craft Launches from Japan,” NASA, July 20, 2012, URL:

71) “NASA Press Kit,” URL:

72) “Japanese Freighter Undocks From Space Station,” Space Travel, Sept. 17, 2012, URL:

73) “HTV-3 Cargo Manifest,” Spaceflight 101, URL:

74) “Kounotori3 (HTV3) Mission,” JAXA, URL:


76) Kazuya Suzuki, Yusuke Matsumura, Shinobu Doi, “Introduction of the Small Satellite Deployment Opportunity from JEM,” Proceedings of the 3rd Nanosatellite Symposium, Kitakyushu, Japan, December 12-14, 2011, URL:

77) “Small Satellites Deployment from Kibo were success,” JAXA, Oct. 5, 2012, URL:

78) Shigeki Kamigaichi, “Earth Observation from the International Space Station - Current status and future,” 17th APRSAF, Melbourne, Australia, Nov. 24, 2010, URL:

79) “Kibo Exposed Facility User Handbook,” JAXA, Sept. 2010, URL:

80) “Ionosphere, Mesosphere, upper Atmosphere, and Plasmasphere mapping (IMAP) mission obtained its first observation data,” JAXA, January 28, 2013, URL:

81) “Global Lightning and sprIte MeasurementS on JEM-EF (JEM-GLIMS) obtained its first observation data,” JAXA, January 31, 2013, URL:

82) K. Higuchi, Y. Ogi, K. Watanabe, A. Watanabe, “Verification of Practical Use of an Inflatable Structure in Space,” Proceedings of the 26th ISTS (International Symposium on Space Technology and Science) , Hamamatsu City, Japan, June 1-8, 2008

83) Naoko Kishimoto, Takahira Aoki, Yasuyuki Miyazaki, Yu Oikawa, Kazuki Watanabe, “On-orbit Verification of Inflatable Space Terrarium on the Exposed Facility of the International Space Station,” Proceedings of the 61st IAC (International Astronautical Congress), Prague, Czech Republic, Sept. 27-Oct. 1, 2010, IAC-10.D3.3.3

84) Takahira Aoki, Ken Higuchi, KazukiWatanabe, SIMPLE Project Team, “Progress Report of SIMPLE Space Experiment Project on ISS Japan Experiment Module,” Proceedings of the 29th ISTS (International Symposium on Space Technology and Science), Nagoya-Aichi, Japan, June 2-8, 2013, paper: 2013-c-07

85) Hiroshi Furuya, Kosei Ishimura, Takafumi Kajikawa, Choji Yoshida, SIMPLE Project Team, “Data Processing of Space Inflatable Membranes Pioneering Long-term Experiments (SIMPLE),” Proceedings of the 29th ISTS (International Symposium on Space Technology and Science), Nagoya-Aichi, Japan, June 2-8, 2013, paper: 2013-c-08

86) Ken Higuchi, Yasuyuki Miyazaki, Kosei Ishimura, Hiroshi Furuya, Hiroaki Tsunoda, Kei Senda, Akihito Watanabe, Nobuyoshi Kawabata, Takeshi Kuratomi, SIMPLE Project Team, “Initial Operation and Deployment Experiment of Inflatable Extension Mast in SIMPLE on JEM Exposure Platform in ISS,” Proceedings of the 29th ISTS (International Symposium on Space Technology and Science), Nagoya-Aichi, Japan, June 2-8, 2013, paper: 2013-c-09

87) Naoko Kishimoto , Yu Oikawa, Mistuhiko Nakano, Kazuki Watanabe, Takahira Aoki, SIMPLE Project Team, “Thermal-blanket Effect Observed in Pressurized Inflatable Terrarium on the ISS,” Proceedings of the 29th ISTS (International Symposium on Space Technology and Science), Nagoya-Aichi, Japan, June 2-8, 2013, paper: 2013-c-11

88) Successful extension of the Inflatable Material experimental Panel (IMP) in the series of the SIMPLE,” JAXA, Nov. 1, 2012, URL:

89) Mitsushige Oda, Masahiro Yoshi, Yoshinori Tabo, Hiroki Kato, Atsushi Ueta, Satoshi Suzuki, Yusuke Hagiwara, Taihei Ueno, “REX-J (Robot Experiment on ISS/JEM) to demonstrate technologies for Astronaut support robots (Astrobot),” Proceedings of the 61st IAC (International Astronautical Congress), Prague, Czech Republic, Sept. 27-Oct. 1, 2010, IAC-10.B3.6.-A5.38

90) Mitsushige Oda, Masahiro Yoshii, Hiroki Nakanishi, Hiroki Kato, Atsushi Ueta, Satoshi Suzuki , Yamazumi, “Preparation of the REX-J mission to demonstrate technologies for the astronaut support robot,” Proceedings of the 28th ISTS (International Symposium on Space Technology and Science), Okinawa, Japan, June 5-12, 2011, paper: 2011-d-27

91) Daichi Hirano, Kazuya Yoshida, Mitsushige Oda, Hiroki Nakanishi, “Experimental Verification of Vibration Control of a Flexible Arm for REX-J Robotic Demonstration on JEM,” Proceedings of the 28th ISTS (International Symposium on Space Technology and Science), Okinawa, Japan, June 5-12, 2011, paper: 2011-d-28

92) Mitsushige Oda, Masahiro Yoshii, Hiroshi Nakanishi, Hiroki Kato, Atsushi Ueta, Satoshi Suzuki, Mitsuhiro Yamazumi, “Development of an Astronaut Support Robot and its Precursor REX-J, to be tested on the International Space Station,” i-SAIRAS (International Symposium on Artificial Intelligence, Robotics and Automation in Space), Turin, Italy, Sept. 4-6, 2012, URL:

93) Mitsushige Oda, Masahiro Yoshii, Hiroki Kato, Atsushi Ueta, Satoshi Suzuki, Yusuke Hagiwara, Taihei Ueno, “REX-J, Robot Experiment on the ISS/JEM to demonstrate the Astrobot’s locomotion capability,” Proceedings of i-SAIRAS (International Symposium on Artificial Intelligence, Robotics and Automation in Space) 2010, Sapporo, Japan, Aug. 29-Sept. 1, 2010

94) Takeshi Kuratomi, Kazuki Watanabe, Taihei Ueno, Mitsushige Oda, “Development of Extendible Robot Arm Experiment Model ISS/JEM-EF,” Proceedings of the 61st IAC (International Astronautical Congress), Prague, Czech Republic, Sept. 27-Oct. 1, 2010, IAC-10.C2.2.5

95) “Operational checkout was performed for the Robot Experiment on JEM (REX-J), as one of the MCE missions,” JAXA, October 31, 2012, URL:

96) “ISS News,” JAXA, URL:

97) “Launch Result of H-II Transfer Vehicle "KOUNOTORI4" (HTV4) by H-IIB Launch Vehicle No. 4,” JAXA Press Release, Aug. 4, 2013, URL:

98) “HTV4 (Kounotori 4) Mission Press Kit,” JAXA, August 2, 2013, Revision A, URL:

99) Daisuke Tsujita, Toru Kasai, Hirohiko Uematsu, Masayuki Harada, Tsutomu Fukatsu, Hiroshi Sasaki, “Experiments plan on the HTV,” Proceedings of the 29th ISTS (International Symposium on Space Technology and Science), Nagoya-Aichi, Japan, June 2-8, 2013, paper: 2013-g-13

100) “Kounotori 4 encapsulated,” JAXA, July 19, 2013, URL:

101) Patrick Blau, “HTV-4 Cargo Manifest,” Spaceflight 101, URL:

102) “HTV4 (KOUNOTORI4) Mission,” JAXA, Aug. 4, 2013, URL:

103) “Vietnam microsatellite carried into space by Japan’s HTV-4 cargo spacecraft,” VAST (Vietnam Academy of Science and Technology), Aug. 5, 2013, URL:

104) “Payload of HTV-4,” JAXA, July 8, 2013, URL:

105) “It may be called the Robotic Refueling Mission (RRM), but NASA built RRM to demonstrate much more than just robotic satellite refueling,” NASA, Aug. 10, 2013, URL:


107) “NRL Space Test Program Experiments Ship to Japan for Flight to the ISS,” NRL, May 15, 2013, URL:

108) Space Test Program to Launch Trio of NRL Space Science and Technology Experiments,” NRL, May 30, 2011, URL:

109) Andrew Williams, “Space Test Program-Houston 4-Active Thermal Tile (STP-H4-ATT),” NASA, May 23, 2013, URL:

110) Tom Flatley, “Space Test Program-Houston 4-ISS SpaceCube Experiment 2.0 (STP-H4-ISE 2.0),” NASA, May 23, 2013, URL:

111) Tom Flatley, “Advanced Hybrid On-Board Science Data Processor - SpaceCube 2.0,” ESTF 2011 (Earth Science Technology Forum 2011), Pasadena, CA, USA, June 21-23, 2011, URL:

112) Tom Flatley, “Advanced Hybrid On-Board Science Data Processor -SpaceCube2.0,” Earth Science Technology Forum, June 23, 2011, URL:

113) Thomas P. Flatley, “SpaceCube: A Family Of Reconfigurable Hybrid On-Board Science Data Processors,” NASA/ESA Conference on Adaptive Hardware and Systems (AHS-2012) Nuremberg/Erlangen, Germany, June 25-28, 2012, URL:

114) Tony Phillips, “ISS Firestation to explore the tops of the thunderstorms,” NASA Science News, Sept. 10, 2013, URL:

115) “Space Test Program-Houston 4-FireStation (STP-H4-FireStation ), NASA, June.26, 2013, URL:

116) Karen C. Fox, “Firestation: Getting Ready for Launch,” NASA Nov. 05, 2012, URL:

117) Jim McLeroy, “Highlights of DoDResearch on the ISS,” June 27, 2012, URL:

118) “Japanese Cargo Craft Captured, Berthed to Station,” NASA, Aug. 9, 2013, URL:

119) “Successful berthing of the H-II Transfer Vehicle "KOUNOTORI 4" (HTV4) to the International Space Station (ISS),” JAXA Press Release, August 10, 2013, URL:

120) “Successful re-entry of H-II Transfer Vehicle “KOUNOTORI4” (HTV4),” JAXA Press release, Sept. 7, 2013, URL:

121) “Cubesats Released From Space Station,” NASA, Nov. 19, 2013, URL:

122) Patrick Blau, “Four CubeSats deployed from Space Station,” Spaceflight 101, Nov. 20, 2013, URL:

123) T. Ebisuzaki, H. Mase, Y. Takizawa, Y. Kawasaki, H. Miyamoto, K. Shinozaki, H. Ohmori, Hachisu, S. Wada, T. Ogawa, F. Kajino, N. Inoue, N. Sakaki, J. Adams, M. Christl, R. Young, M. Bonamente, A. Santangelo, M. Teshima, E. Parizot, P. Gorodetzky, O. Catalano, P. Picozza, M. Casolino, M. Bertaina, M. Panasyuk, B.A. Khrenov, I.H. Park, A. Neronov, G. Medina-Tanco, D. Rodriguez-Frias, J. Szabelski, P. Bobik R. Tsenov for the JEM-EUSO collaboration, “The JEM-EUSO Mission,” Proceedings of the 28th ISTS (International Symposium on Space Technology and Science), Okinawa, Japan, June 5-12, 2011, paper: 2011-h-05

124) M. Tamura, T. Matsuo, “ISS/JEM,” URL:

The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates.