Flying Laptop is a
microsatellite of the Institute of Space Systems (Institut für
Raumfahrtsysteme, IRS) at the University of Stuttgart, Germany. The
primary mission objective is to demonstrate and qualify new
technologies for future projects. A goal is also to conduct various
scientific Earth observation experiments. Research topics of special
interest are: 1) 2) 3) 4) 5) 6) 7) 8)
• Measurement of the BRDF (Bi-directional Reflectance Distribution Function) in the visible spectrum as
well as the temperature directional distribution
• Demonstration of a new method of precipitation measurements
• Study of atmospheric attenuation in the Ka-band frequency range
• Multispectral Earth observation
Figure 1: Artist's rendition of the Flying Laptop spacecraft (image credit: IRS Stuttgart)
The spacecraft structure is a box of
size 60 cm x 60 cm x 70 cm with a total mass of < 120 kg. The
mechanical structure of the satellite is divided into the service
module, the core module and the payload module (Figure 2).
design allows a convenient access to the internal components and
ensures simultaneous integration of the modules. All segments are made
of aluminium due to its high heat conduction properties. Furthermore
the three modules are held together by rods, which go through the whole
structure and are fixed by locknuts. All optical instruments are
mounted onto an optical bench, consisting of a CFRP (Carbon
Fiber-Reinforced Plastic) sandwich
with an aluminium honeycomb core, to insure optical alignment and to
minimize thermal expansion effects. 9)
Figure 2: Modular design of the Flying Laptop satellite (image credit: IRS Stuttgart)
Figure 3: Illustration of the Flying Laptop microsatellite (image credit: IRS, Stuttgart)
The core module of the satellite
features of a reconfigurable, redundant, self-controlling FPGA (Field
Programmable Gate Array) onboard computer system with considerable
computational power. This computer system
makes it possible to offer a 'Rent-a-Sat' mode service, providing a
platform for software testing in space. Flying
Laptop is a low-cost project by using COTS (Commercial-Off-The-Shelf)
components whenever possible.
Flying Laptop is 3-axis stabilized. The requirements call for high-accuracy pointing (150 arcsec or 0.042º) and
agile maneuvering capabilities for the imaging mission. The actuators of the ACS (Attitude Control Subsystem)
feature four reaction wheels (RW), and three magnetic torquers (these are torque rods for momentum dumping of
the reaction wheels). Attitude sensing is provided by two 3-axis magnetometers, two coarse sun sensors (6º rms
pointing), four fiber-optic rate sensors, one autonomous star tracker (fine pointing accuracy of < 2 arcsec), and
three GPS receivers (GENIUS). 10) 11) 12)
Pointing knowledge, absolute
±7 arcsec (±1 pixel)
Pointing knowledge, relative
±2.5 arcsec (±1/3 pixel)
±150 arcsec (± 20 pixel)
Table 1: Pointing parameters of the ACS
An explanation/description is due to some of the various ACS and S/C subsystem components:
• In this context, GENIUS (GPS Enhanced NavIgation system for the University of Stuttgart micro-satellite) is
an onboard experiment being conducted in cooperation with DLR/GSOC (Figures 4 and 5).
GENIUS consists of
three COTS Phoenix GPS boards. Each of the receivers is connected to
separate GPS antenna via a low noise amplifier. The antennas of three
separate GPS receivers are being placed on three corners of the
central solar array in an L-shape configuration. The GENIUS performance
offers real-time position, velocity
and timing information with estimated accuracies of 10 m, 0.1 m/s and 1
µs, respectively (in addition attitude is
being provided). The Phoenix GPS receiver is a commercial GPS receiver
board with a new DLR/GSOC developed firmware for space and high
dynamics applications. The receiver has 12 tracking channels and is
able to measure phase and Doppler shift of the GPS-L1 carrier signal.
Figure 4: Configuration of the GENIUS system (image credit: DLR/GSOC)
Figure 5: Illustration of GPS antenna allocations (image credit: IRS)
The GENIUS GPS system consists of
three independent GPS receiver boards, each connected to a separate
antenna and low noise amplifier (LNA) as shown in Figure 4. The GPS Box is connected to the on-board computer
(OBC), the power control and distribution unit (PCDU) and the ultra stable oscillator (USO). The used Phoenix
boards are commercial 12-channel GPS L1 receivers with a DLR/GSOC developed firmware for space and high
dynamics applications. Three GPS antennas are mounted on the middle solar panel in an L-shaped arrangement,
creating two baselines with a length of 440 mm and 610 mm respectively (Figure 5). The three GPS receivers are
integrated in a single 100 mm x 80 mm x 67 mm box together with an interface board for RS-422 conversion, the
USO signal distributor and a latch-up protection for each receiver. To achieve a high level of redundancy, each
receiver can be switched on/off independently varying the system input power from 0.9 W for 1 receiver to 2.6 W for
all 3 receivers according to measurements at the testing model.
An algorithm based on a Kalman
Filter is used to process the measurement data and produce an offline
solution which will be compared to the attitude information available
from the satellite's star camera. The algorithm uses the lambda-method
to resolve the integer ambiguities of the double differences of the
measurements. These resolved double difference ambiguities are then
used to fix the single difference ambiguities
in the filter. Hence, the algorithm provides a seamless transition from
the ambiguity resolution to the attitude determination.
• STR (Star Tracker): The autonomous star tracker in the ACS configuration is the newly developed µASC
(micro Advanced Stellar Compass) of DTU (Technical University of
Denmark), Lyngby, Denmark. In fact, µASC is of
ASC heritage flown on Ørsted, SAC-C, CHAMP, GRACE, ADEOS-2,
SMART-1, GOCE, etc. The µASC instrument is physically divided
into a µDPU (micro Data Processing Unit) with hot/cold redundancy
(Camera Head Unit), a µDPU may drive up to 4 CHUs (2 CHUs are
being used on Flying Laptop). The intrinsic
accuracy of an attitude measurement from a single CHU is better than 1
arcsec at an integration time of 0.5 s. This
attitude is autonomously calculated based on all brighter stars in the
FOV of the CHU. The µASC on Flying Laptop provides a pointing
knowledge within 2 arcsec. Furthermore, µASC delivers attitude
information at S/C angular rates of up to 10º/s and thus enables
rapid repointing of the platform to any object. This attitude is
calculated based on all brighter stars in the FOV of the CHU. The
µASC on Flying Laptop needs to provide a
pointing knowledge of one pixel at 7.4 arcsec.
The use of µASC on Flying Laptop is an early spaceborne demonstration of this instrument. Currently PROBA-2
is another mission under development using the µASC device (launch planned for late 2007). 13)
Figure 6: Illustration of the µASC instrument (image credit: IRS)
Figure 7: View of a camera head unit and baffle (image credit: IRS)
• The three magnetic torque rods employed are developed by ZARM Technik, Bremen, with a linear dipole
moment of 6 Am2. The torquers are connected to a power box that includes two I2C buses for connection to the
OBC. The whole system is single redundant.
• Magnetometer: ZARM Technik
provides also the AMR (Anisotropic-Magneto-Resistive) magnetometer,
a microcontroller-based 3-axis magnetometer with digital output. Two
magnetometers are being installed on the
microsatellite. The Earth's magnetic vector field is being used as
input information for the magnetic torquers (detumbling after launcher
separation, etc.). The ARM sensor is the HMC-1023 model of Honeywell.
• The angular rate of the S/C
is measured with 4 single-axis COTS fiber optic rate gyros (FOG) in a
tetrahedron configuration. The sensors employed are C-FORS (Commercial
Fiber Optic Rate Sensor) of Litef. The
complete FOG assembly has a mass of ~1.7 kg.
• Electrical power is being provided by three solar panels, two of which are deployable (total area of approx. 1
m2). Use of triple-junction GaAs solar cells with an efficiency of 26%. In addition, the satellite is being used as an
on-orbit testbed for the new generation of penta-junction solar cells with an efficiency higher than 30%. These
cells are only used for demonstration (technology evaluation), they are not considered for energy supply and are
being mounted on the side panels.
Figure 8: Electrical architecture of the spacecraft (image credit: IRS Stuttgart)
Figure 9: Overview of the ACS sensors and actuators (image credit: IRS Stuttgart)
OBC (Onboard Computer):
Flying Laptop will probably be the first microsatellite of using an
system routinely and exclusively. [Note: The Australian FedSat
microsatellite (launch Dec. 14, 2002) was developed for in-orbit
evaluation of RAM-based FPGAs - an experiment]. The OBC of Flying
Laptop is based on a
Xilinx Vertex-II Pro with approximately 3 million system gates and a
clock frequency of up to 200 MHz. Furthermore, the OBC configuration is
using 4 MB of synchronous static RAM for high speed data processing, 2
x 128 MB
DDR RAM (Double Data Rate-Random Access Method) and 1 GB flash memory.
A user-programmable EEPROM (Electrically Erasable Programmable
Read-Only Memory) on board can be reconfigured from the
ground station via modem. In case of failure, the original FPGA
configuration is restored from a PROM.
The OBC consists of four CPNs
(Central Processing Nodes) and one CDV (Command Decoder and Voter).
are connected with each other through a back plane (BPL) and with the
other peripheral electronics through a CIB
(Connector Interface Board). The CPNs are based on a reconfigurable
FPGA with high computational ability and
planned to be reconfigured during on-orbit operation controlled by the
CDV, which is also a FPGA-based computer. The CPN can also be loaded
with a soft core of a microprocessor so that third parties can verify
software in a 'Rent-A-Sat Mode' configuration on orbit. The data
handling system of the Flying Laptop is integrated system on OBC and it
holds the highest authority and performs most of the data handling
onboard. The advantages of the FPGA-based CPN against traditional
microprocessor-based computers are:
• Reconfigurability of the system
• Start-up and reset within several ms
• Precise timing
• No interference between processes
• Reduction of hardware interfaces.
Figure 10: Block diagram of the CPN (image credit: IRS Stuttgart)
The OBC system is being designed and developed by the Steinbeis Transferzentrum Raumfahrt in Gäufelden,
Germany, in cooperation with the Fraunhofer Institute for Computer Architecture and Software Technology
(FIRST), Berlin. The OBC operating system is referred to as BOSS, developed by FIRST. BOSS is a real-time
embedded operating system with integrated middleware, designed for safety and simplicity and to conduct its own
mathematically formal verification.
The OBC on Flying Laptop differs
significantly from computers on other S/C: In the nominal mode, the OBC
operate solely with algorithms implemented directly in hardware. No
control software will be running. This is being
made possible by using a compiler (Celoxica Handel-C) that allows for
the direct generation of an FPGA configuration by using a special
version of the "C" programming language without the need for a HDL or
method provides short development times and a complexity of the
algorithms that is otherwise hardly to achieve.
The direct hardware synthesis provides the fasted processing speed and
has a hard real time behavior without any
latencies. 14) 15)
Example: Using a FPGA for the ACS
implies that the control and navigation algorithms will not run as
are implemented in hardware. Thus, algorithms run with the speed of
dedicated hardware circuits, but can be
created with the programmability of software. This is a different
approach for designing a system. Extensive parallel execution and cycle
precise synchronization between parallel routines is possible, which in
turn allows very accurate timing.
implementation of an FPGA design in Handel-C usually consists of three
layers. The uppermost layer is the
user application layer, where the high level functionality and
algorithms are implemented. Hence, these are the
ACS algorithms, the FDIR and the TM logger. This layer is independent
of the FPGA hardware board it runs on.
The FPGA and board specific functionality is included in the remaining
two layers, the Platform Abstraction Layer
(PAL) and the Platform Support Library (PSL). The Platform Abstraction
Layer can consist of multiple PAL APIs,
where each contains the functionality of a specific resource. For the
Flying Laptop ACS interfaces the serial interface functionality of the
Standard-PAL API is used. Further input and output functionality that
is needed for the
ACS is contained in the Satellite Hardware Interface Protocol (SHIP)
API. In the SHIP API, the I2C bus and the
IBIS bus are implemented. The I2C bus is used for the magnetic torquers and for the sun sensors. The IBIS bus
controls the communication with the fiber optic rate sensors.
Figure 11: Overview of the OBC software architecture (image credit: IRS Stuttgart)
RF communications: For
telemetry and telecommand UHF, VHF (low gain) and S-band (low and high
gain) antennas are being installed on the satellite. Besides S-band,
the VHF/UHF link offers the possibility to utilize amateur radio
The Flying Laptop is also equipped with a Ka-band traveling wave tube (TWT) amplifier in support of its payload
measurement functions. On a ground station pass, the TWT operates with an RF transmission power of 57 W
(170.5 W DC input) which is unique for a microsatellite. A data rate of up to 100 Mbit/s can be supported with this
satellite's Cassegrain system with its 50 cm primary dish provides the
antenna reflector for the Ka-band communication and is also used as the
optical system element for the thermal infrared camera (TICS). The TWT
design driver for the Li-ion battery system (50 Ah, 6 cells) to handle
its high power requirement (for a maximum
duration of 20 minutes of operations support).
The microsatellite will be operated
by students at IRS (Institut für Raumfahrtsysteme), of the
University of Stuttgart. The existing ground station on campus is being
upgraded to permit satellite communications in the following
frequency bands: UHF, VHF, L-band, S-band and Ka-band (payload
Launch: The launch of the Flying Laptop satellite as a secondary payload is scheduled for 2008 on a PSLV launcher
Orbit: A sun-synchronous polar circular orbit with an altitude of about 700 km.
Sensor complement: (MICS, TICS)
The scientific payload of the satellite is a triple imaging system, a VNIR (Visible Near-Infrared) system called
MICS, a TIR (Thermal Infrared ) camera, and a Ka-band communication/imaging system (called TICS). The last
two instruments are intended to make dual use of a cassegrain mirror system.
MICS (Multispectral Imaging Camera System). The objective is to observe in the VNIR range of the spectrum in
three bands at medium resolution (GSD of 25 m). MICS consists of three single cameras, each with an area array
CCD detector for snapshot observations.
530 nm - 580 nm (green)
620 nm - 670 nm (red)
820 nm - 870 nm (NIR)
GSD (Ground Sample Distance)
Instrument mass, power ,size
~4 kg, ~5 W, 100 mm x 90 mm x 400 mm
Table 2: Key parameters of the MICS instrument
The optical system uses a double Gauss telescope with interference filters placed in front of the system. The use of
an area array detector has advantages for the measurement of the BRDF and allows easier referencing on ground.
The BRDF measurements will be done in the target-pointing mode, where the satellite is focused on the target
site during the whole passage.
In order to accomplish reliable scientific measurements, periodic calibration of the instrument is mandatory, not
only on ground, but also in space. A particular LED (Light Emitting Diode) device is being used to verify the following items:
• Pixel-to-pixel shift (flat-field calibration)
• Spectral shift of interference filters
• Radiometric performance.
Figure 12: Schematic sectional drawing of MICS (image credit: IRS Stuttgart))
TICS (Thermal Infrared Camera System). The objective is to observe in the TIR (Thermal Infrared) wavelength
range of 8-12 µm (excluding the oxygen absorption band from 9.3-9.7 µm), using an uncooled microbolometer
detector array of size 320 x 240 pixels (snapshot imagery). The detector is temperature stabilized and cooled by
Peltier elements in order to achieve the desired SNR (Signal-to-Noise Ratio).
The TICS optics system consists of a
Cassegrain system (f/1.6), designed as a dual-band system (it serves as
a telescope for the TIR range, and as antenna for the Ka-band signals),
as well as relay optics. The primary mirror (500
mm aperture diameter) of the Cassegrain optics system as well as the
retaining structure of the secondary mirror
are being produced from CFRP (for temperature stability and alignment).
The TICS instrument is providing a
GSD (Ground Sample Distance) of 50 m in TIR.
Pointing modes for image acquisition:
Three attitude control modes have been defined for image acquisition:
1) Inertial pointing mode: In this mode, the star sensor is being used to provide high accuracy pointing knowledge
of 7.5 arcseconds. The satellite will be and will also remain inertially stabilized, i.e. the coordinate system of
the satellite will maintain in the same orientation with respect to stars. Note: This mode is not useful for taking
Earth imagery. Other observations (e.g. stars, moon) are possible.
2) Nadir pointing mode: In this mode the satellite is being aligned in the direction of the Earth, i.e. the z-vector
of the satellite's coordinate system is perpendicular to the Earth's surface; hence, the angular rate remains
constant. This mode is also called the "Earth-pointing mode," being used for image acquisition, attenuation
measurements and trace gas detection.
3) Target-pointing mode (or spotlight mode):
This mode is being used to achieve the required coverage/resolution of
the planned scientific observations. In this mode, the S/C points at
fixed target (spot an Earth's surface)
during an extended period of time thereby achieving a TDI (Time Delay
Integration) effect. The spotlight
service requires a slewing of the S/C to keep the instruments pointed.
The maximum slew rate for this maneuver is 1º/s. This is the most
demanding support mode of the satellite in terms of control algorithms.
Figure 13: Imaging modes: A) Inertial-, B) Nadir- and C) Target-pointing mode (image credit: IRS Stuttgart)
Research experiments and technology demonstrations:
The sensor complement and the Ka-band antenna are intended to be used as research tools in the field of Earth
observation through remote sensing. The following topics will be investigated:
• BRDF (Bi-directional Reflectance Distribution Function) measurements: In the target pointing mode, this
function is measured in different spectral bands (visible, near infrared, and thermal infrared). The cameras take
imagery continuously of the same target area during a small segment of the orbit - at various observation angles,
resulting in bi-directional reflectance measurements. Obviously, homogeneous ground surfaces like large forests
or deserts represent ideal targets for this support mode.
BRDF specifies the behavior of surface scattering as a function of illumination and view angles at a particular
wavelength. BRDF is defined as being the ratio of the reflected radiance to the incident flux per unit area. As such,
the BRDF function plays a decisive role in the analysis of spaceborne remote sensing data.
• Demonstration of precipitation measurements in Ka-band:
Experiments have shown, that the differential
radio signal attenuation in a horizontal path through rain in two
different frequency ranges (between 10 and 40
GHz) is linearly dependent on the rain rate. The target pointing mode
is being used to acquire precipitation measurements in Ka-band and
Ku-band. Note: The rainfall determination requires the differential
the signal attenuation at two two distinct frequencies. For the
Ka-band, the second frequency should be in the
Ku-band (this is being implemented by another onboard Ku-band
The Ka-band antenna with its large bandwidth is being used for the study of atmospheric attenuation within this
frequency range. The Ka-band signal is influenced by a variety of causes in the atmosphere:
- Attenuation through rain
- Attenuation through clouds
- Attenuation through atmospheric constituents
- Instability of the atmospheric refraction index
- Phase transformations from ice particles to water droplets
The objective is to retrieve the total content of various trace gases.
• Multispectral observations:
Simultaneous observations are planned with all cameras. In addition,
the Ka-band antenna with its high power will also be used as a radar
transmitter (providing a GSD of 25 km). The signal
will be transmitted from space, but the reflected signal needs to be
captured with the help of measurement towers
on the ground, not at the satellite. The broadband Ka-band signal
permits data rates of up to 100 Mbit/s.
• The implementation of the TWT amplifier with a transmission power of 57 W represents a new capability for
• FPGAs: The
introduction and reliance of onboard computing with an FPGA system
represents a new approach to conventional system architectures. It
provides the capability to directly generate the logical configuration
of FPGA gates from a C-like high level language without producing the
machine code for a processor (hence,
massive parallel processing is possible). Using an onboard computer
architecture with several reciprocative checking FPGAs, a safe system
is obtained that even exceeds the performance of current PCs through
its ability of parallel real-time processing. An inherent advantage of
FPGA architectures is the capability of reconfiguration within
To make the system fault-tolerant and to address radiation issues, four equal independent nodes work together.
Depending on the state of the system, 1-4 nodes may run in parallel; they may be switched on or off dynamically.
• NEA (Near Earth
Asteroid) detection. Aside from delivering attitude information, the
star tracker in use possesses a built-in feature to automatically
detect, identify and track any other faint luminous object, not being a
star, as long as the object is brighter than the visual (or apparent)
magnitude Mv 11.
The Technical University of Denmark (DTU) has proposed an interplanetary mission to search for Near Earth
Asteroids (NEA), based on their star tracker, µASC. Observation time for these science experiments of the Flying
Laptop will be made available to test and verify this concept, in the eclipse phase of the LEO orbit (for further
information see reference 6).
• Rent-a-Sat mode: The
inherent high flexibility of the onboard computer system will be used
to operate the
Flying Laptop in a so-called 'Rent-a-Sat' mode. Interested parties
(companies or institutions) can rent the satellite as a development
platform in space. It is possible to configure the system for customer
preferences (i.e., the
characteristics of a certain processor can be simulated through the
hardware). With this versatility the 'Rent-a-Sat' system is well suited
for spaceborne software or firmware validations.
• PanCam (Panoramic Camera) is an additional COTS camera on Flying Laptop to provide context color video
imagery of Earth . PanCam is required because the narrow FOVs of the two science imagers (MICS and TICS) are
insufficient for context information imagery to increase public outreach of the Small Satellite Program. PanCam
uses CMOS technology with a pixel pitch of 6.7 µm. It has 1280 x 1024 pixels and can capture up to 27 images per
second in full resolution. Using a focal length of approximately 25 mm, the sensor can cover a FOV of 20º x 16º.
This results in a swath width of approximately 250 km and a ground sample distance of around 200 m from a 700 km
orbit. The video link of PanCam employs a lossy video compression technique to be able to handle the large source
data volume. 16)
G. Grillmayer, M. Hirth, F. Huber, V. Wolter, "FPGA Based Attitude
Control System Architecture for Increased Performance," Proceedings of
20th Annual AIAA/USU Conference on Small Satellites, Logan, UT, Aug.
14-17, 2006, paper: SSC06-VI-8
G. Grillmayer, M. Lengowski, S. Walz, H.-P. Roeser, F. Huber, M. v.
Schoenermark, T. Wegmann, "Flying Laptop - Microsatellite of the
of Stuttgart for Earth Observation and Technology Demonstration,"
Proceedings of IAC 2004, Vancouver, Canada, Oct. 4-8, 2004,
4) Information provided by Georg Grillmayer of IRS at the University of Stuttgart
S. Walz, M. Lengowski, M. von Schoenermark, "Payload and Scientific
Investigation of the Flying Laptop," Proceedings of the 5th IAA
on Small Satellites for Earth Observation, Berlin, Germany, April 4-8,
G. Grillmayer, A. Falke, H.-P. Roeser, "Technology Demonstration with
the Microsatellite Flying Laptop," Proceedings of the 5th IAA Symposium
on Small Satellites for Earth Observation, Berlin, Germany, April 4-8,
H.-P. Roeser, F. Huber, G. Grillmayer, M. Lengowski, S. Walz, A. Falke,
T. Wegmann, "A small satellite of the University Stuttgart - a
for new techniques," Proceedings of the 31st International Symposium on
Remote Sensing of Environment (ISRSE) at NIERSC (Nansen International
Environmental and Remote Sensing Center), Saint Petersburg, Russia,
June 20-24, 2005
T. Kuwahara, F. Huber, A. Falke, M. Lengowski, S. Walz, G. Grillmayer,
H.-P. Röser, "System Design of the Small Satellite Flying Laptop,
Technology Demonstrator of the FPGA-based on-board Computing System,"
58th IAC (International Astronautical Congress), International
Space Expo, Hyderabad, India, Sept. 24-28, 2007, IAC-07- B4.6.08
M. Lengowski, H.-P. Roeser, R. Haarmann, U. Beyermann, G. Gebel,
"Mechanical Design of the Micro-Satellite Flying Laptop," Proceedings
of the 6th IAA Symposium on Small Satellites for Earth Observation,
Berlin, Germany, April 23 - 26, 2007
M. Waidmann, C. Waidmann, D. Saile, G. Grillmayer, V. Wolter, "Use of
new developments on attitude control sensors for the microsatellite
Laptop," Proceedings of the 57th IAC/IAF/IAA (International
Astronautical Congress), Valencia, Spain, Oct. 2-6, 2006, IAC-06-B5.6.18
A. Hauschild, G. Grillmayer, O. Montenbruck, M. Markgraf, P.
Vörsmann, "GPS Based Attitude Determination for the Flying Laptop
Proceedings of the 6th IAA Symposium on Small Satellites for Earth
Observation, Berlin, Germany, April 23 - 26, 2007
A. Brandt, I. Kossev, A. Falke, J, Eickhoff, H.-P. Roeser, "Preliminary
System Simulation Environment of the University Microsatellite Flying
Laptop," Proceedings of the 6th IAA Symposium on Small Satellites for
Earth Observation, Berlin, Germany, April 23 - 26, 2007
J. L. Jørgensen, P. S. Jørgensen, G. Grillmayer, "NEA
detection, a possible use of the Flying Laptop microsatellite
of the 5th IAA Symposium on Small Satellites for Earth Observation,
April 4-8, 2005, Berlin, Germany
S. Montenegro, H.-P. Röser, F. Huber, "BOSS: Software and FPGA
Middleware for the "flying laptop" Microsatellite," DASIA 2005 (DAta
Systems In Aerospace), May 30 - June 2, 2005, Edinburgh, Scotland, UK;
A. Falke, G. Grillmayer, S. Walz, F. Hesselbach, J. Eickhoff( H.-P.
Roeser, "LED in-flight calibration and model-based development of ACS
algorithms for the university microsatellite Flying Laptop,"
Proceedings of the 4S Symposium: `Small Satellite Systems and
Services,' Chia Laguna
Sardinia, Italy, Sept. 25-29, 2006, ESA SP-618
Lachenmann, S. Walz, H.-P. Roeser, "Video Compression of the Flying
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Symposium on Small Satellites for Earth Observation, Berlin, Germany,
April 23 - 26, 2007
This description was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" - comments and corrections to this article are welcomed by