ISS: SIMPL (Satlet Initial-Mission Proofs and Lessons)
|06 Dec 2015
ISS Utilization: SIMPL (Satlet Initial-Mission Proofs and Lessons) / Kaber (NanoRacks Microsat Deployer)
SIMPL is a microsatellite of NanoRacks, it is a modular satellite known as HISat (Hyper-Integrated Satellite) designed to provide complete satellite functionality in a nanosatellite scale. It will be the first NanoRacks microsatellite deployed from the space station and the first propulsion-capable satellite deployed from the NanoRacks Microsat Deployer, known as Kaber. The commercial deployer system aims to address the growing market of customers wanting to deploy microsatellites from the ISS orbit. SIMPL will be the first NanoRacks microsatellite deployed through the Kaber facility.
The NanoRacks Kaber mission SIMPL investigation studies small components called satlets, which are building blocks of larger satellites that are launched from the NanoRacks Microsat Deployer. The satlets are combined to form larger satellites or satellite constellations that share power, data and other resources and perform many different tasks. The SIMPL concepts have been designed and developed at NovaWurks Inc. of Los Alamitos, CA with Talbot Jaeger of NovaWurks as PI (Principal Investigator) and Walt Mirczak of NovaWurks as Co-PI. NASA is the sponsoring agency of SIMPL. 1) 2)
• NovaWurks Inc. pioneered the HISAT (Hyper-Integrated Satlet) technology, a concept to assemble larger satellites from small independent "cells" called satlets.
• NovaWurks HISats are independent and fully functional nanosatellites with their own propulsion, power, navigation, data processing, communications and payload accommodations.
• HISats also have mechanical, electrical and data interfaces to easily support accommodation of third party payloads.
• The NanoRacks Kaber Mission-1, along with the SIMPL -Microsat of NovaWurks, is a microsatellite technology demonstrator designed and built by NovaWurks Inc. to demonstrate innovative technology and is assembled by crew members and deployed from the ISS (International Space Station) using the Kaber (NanoRacks Microsat Deployer).
• The NanoRacks-NovaWurks SIMPL-Microsat demonstrates manual crew member assembly in microgravity of eight subassemblies utilizing minimal tools and simple mechanical and electrical connections.
• The NanoRacks-NovaWurks SIMPL-Microsat mission proves the HISat technology on orbit, will reduce risk for follow on HISat-capable missions, and enables commercial utilization of the cellularized technology developed by NovaWurks Inc. for payloads utilizing either ISS or ELV (Expendable Launch Vehicle) access to space.
The NanoRacks Kaber Mission-1, along with the SIMPL -Microsat of NovaWurks, is the on-orbit assembly and LEO (Low Earth Orbit) deployment demonstration of the NovaWurks HISat (Hyper-Integrated Satlet) system. The research utilizes a cargo vehicle flight to the ISS with six HISats and supporting payloads manifested. To demonstrate their packaging efficiency in the pressurized area of the ISS cargo vehicle the HISats are packaged individually. The disassembled cargo vehicle configuration enables a demonstration of the ease of on-orbit HISat assembly into a microsatellite, also known as a PAC (Package of Aggregated Cells). 3)
The HISat Satlets of NovaWurks are homogeneous, autonomous satellites complete with propulsion, communications, power, and attitude control systems. Each Satlet has approximate dimensions of 20 cm x 20 cm x 10 cm. Individual HISats have lockable connectors enabling them to be mechanically connected to form a larger configuration capable of sharing power, data, and thermal interfaces. The NanoRacks-NovaWurks SIMPL-Microsat applies terrestrial WiFi (Wireless Fidelity) technology and hardware to inter-satlet communications utilizing a multiple node mesh network architecture. Each HISat can accommodate external payloads using an interface adaptor. HISats provide an app-based, open-source approach to core resource-sharing cellular software that provides for simple user-created applications to coordinate their requisite payload and mission needs.
Space Applications: This investigation demonstrates small satellite components that can be interconnected in dozens of ways to support varying missions. The satellite components, or HISats (Hyper-Integrated Satlets), are interchangeable, which provides backup support in case some parts fail. The satlets are autonomous and have their own propulsion, communications, power and control systems, and they have interlocking connectors that allow them to share resources and work together in larger configurations, supporting a variety of spaceborne research projects.
Earth Applications: Satellites built of many smaller parts can be used for a variety of missions that benefit research on Earth, including Earth observation, data transfer, ship and airplane monitoring, carbon dioxide monitoring, and more. Launching multiple smaller components and assembling them in space reduces the cost of launch, expanding access to LEO. In addition, this investigation carries an amateur radio designed and built by students at the US Naval Academy, providing training in science, technology, engineering and mathematics.
Operational Requirements: NanoRacks-NovaWurks-SIMPL-Microsat mission requirements include crew resources for on-orbit assembly and pre-deployment logistics. Deployment is to occur as soon as possible after ISS reboost to maximize orbital lifetime. Video and photogrammetry services to characterize the NanoRacks Microsat Deployer deployment kinematics and provide payload developer mission assurance feedback and ephemeris data at the time of deployment.
Operational Protocols: ISS crew assembly procedures have been prepared to guide the crew through proper and safe assembly of the NanoRacks-NovaWurks-SIMPL-Microsat PAC. The JEM/Kibo airlock and MSS SPDM operations are governed by the standard operations in place for those resources. Following deployment by the NanoRacks Microsat Deployer, NanoRacks-NovaWurks-SIMPL-Microsat flies an autonomous mission.
The benefits of HISat technology include cost, flexibility, and robustness. HISats are designed to be interconnected in a vast number of configurations (known as Packages of Aggregated Cells, PACs), which can be tailored to support a wide variety of missions. As HISats are interchangeable, assembled PACs with inherent multiple levels of redundancy increase the overall probability of mission success. SIMPL is not only a precursor to constellations of HISat-based PACs that can perform Earth observation, data relay, maritime and aviation monitoring, and carbon monitoring, but also to deep-space exploration, asteroid mining, and many other missions serving mankind.
Legend to Figure 2: SIMPL is a six-HISat PAC (Package of Aggregated Cells) and with two deployable solar arrays (total of 8 components).
Kaber (NanoRacks Microsat Deployer System) - a Microsatellite Deployer on the ISS
The NanoRacks Kaber Microsat Deployer (NanoRacks Microsat Deployer) is a reusable system that provides command and control for microsatellite deployments from the ISS (International Space Station). NanoRacks developed the Kaber leveraging its experience deploying CubeSats from the ISS. The Kaber enables NanoRacks to support deployment into space of microsatellites in the mass range of 50 - 100 kg from the ISS. Kaber promotes ISS utilization by enabling deployment into orbit for a class of payload developers normally relying on expendable launch vehicles for space access. Microsatellites that are compatible with the NanoRacks Kaber have additional power, volume and communications resources enabling missions in low Earth orbit of more scope and sophistication. 4) 5)
• The NanoRacks Kaber Microsat Deployer (NanoRacks Microsat Deployer) is a reusable system that provides command and control for satellite deployments via the JEM Airlock from the ISS.
• The NanoRacks Microsat Deployer has a mass of about 10 kg with approximate dimensions of 40 cm x 42 cm x 31 cm.
• Kaber maintains a mechanical and electrical interface between the satellite separation system and the International Space Station / Mobile Servicing System / Special Purpose Dexterous Manipulator (ISS / MSS / SPDM) and to the JEM (Japanese Experiment Module) airlock slide table.
• The NanoRacks Microsat Deployer accommodates microsatellites up to a mass of 100 kg with approximate dimensions 95 cm x 83 cm x 64 cm (max).
Legend to Figure 4: This photo shows the black colored circular Kaber flange and box shaped Kaber housing. The brass colored robotic SPDM electrical interface is visible on the top of the Kaber housing. The gold colored microsquire fixture on atop the CLPA mate/demate wedge is the grapple point for the SPDM. Also shown in this photo is the white colored CLPA mate/demate wedge protective cover. Image courtesy of NanoRacks (Ref. 1).
The SIMPL microsatellite along with Kaber (NanoRacks Microsat Deployer) was launched on December 6, 2015 (21:44:57 UTC) on the Cygnus Orbital ATK CRS-4 (Commercial Resupply Services-4) mission from the Cape Canaveral Air Force Station, FL. Orbital ATK used the services of ULA (United Launch Alliance) Atlas-5 rocket to fulfil the CRS contract with NASA. The total payload packed on board was 3513 kg, including science investigations, crew supplies, vehicle hardware, spacewalk equipment and computer resources. 6) 7)
Orbit: The near-circular orbit of the ISS is at a nominal altitude of ~400 km with an inclination of 51.6º.
- Flock-2e, 12 3U CubeSats of Planet Labs
- CADRE, a 3U CubeSat technology mission of the University of Michigan
- MinXSS-1, a 3U CubeSat solar physics mission of the CU (University of Colorado) at Boulder
- NODES (Network & Operation Demonstration Satellite), two 1.5 CubeSats of NASA
- STMSat-1 (Saint Thomas More School Satellite), Arlington, VA, 1U CubeSat.
- SIMPL (Satlet Initial-Mission Proofs and Lessons), a microsatellite of NovaWurks along with Kaber of NanoRacks.
• On October 27, 2017, NanoRacks successfully deployed NovaWurks' SIMPL satellite via the Company's Kaber Microsatellite Deployer (KABER) from the ISS (International Space Station) early this morning. This is the second Kaber-class deployment that NanoRacks completed this week. 8)
- SIMPL went beyond standard satellite deployment from the Space Station. For this program, NovaWurks Inc. pioneered the Hyper-Integrated Satlet (HISat™) technology, a concept to assemble larger satellites from small independent "cells" called satlets. Specifically, SIMPL was delivered to the ISS via NanoRacks in a few larger groups, and then assembled this week by the astronaut crew utilizing some smaller components.
- "This was far more than just another satellite deployment for us here at NanoRacks," says NanoRacks External Payloads Manager, Conor Brown. "For the first time ever a complex satellite was assembled on orbit from multiple satlets launched as separate spacecraft. Thanks to the innovative work of the NovaWurks team and the incredible coordination between our Operations team, NASA, and the ISS crew, we were able to achieve a major milestone towards the future of human and robotic manufacturing of satellites on orbit."
- These NovaWurks satlets can also be combined to form larger satellites or satellite constellations that share power, data, and other resources to perform different tasks.
• The Cygnus Orbital ATK CRS-4 vehicle departed the ISS on Feb. 19, 2016 after successfully resuming America's train of resupply runs absolutely essential to the continued productive functioning of the orbiting science outpost. Prior to its departure, the astronauts loaded the cargo module with over 1,400 kg of items for disposal. Cygnus performed a safe, destructive reentry into the Earth's atmosphere over the Pacific Ocean east of New Zealand on February 20 at approximately 16:00 UTC, marking the successful conclusion of the mission. 9) 10)
• The individual HISat cells (8 components) of SIMPL were delivered to the International Space Station in December 2015. The ISS crew assembly procedures were prepared to guide the crew through proper and safe assembly of the SIMPL PAC. The assembly aboard the ISS, scheduled to occur before May 20, 2016, will demonstrate the ease of on-orbit HISat assembly into a microsatellite, or PAC (Package of Aggregated Cells). 11) 12) 13)
- As a pathfinder, SIMPL also successfully achieved ISS EVA (Extravehicular Activity) and IVA (Intravehicular Activity) approvals so that future assemblies can be deployed through the JEM airlock, grappled by an ISS robotic arm, positioned in a safe deployment position and orientation, and then be released by the NanoRacks Kaber Microsat Deployer.
- SIMPL received ISS program office approval for stowage in the ISS and subsequent assembly by an ISS crew member. SIMPL is currently in stowage awaiting ISS crew time for assembly. The SIMPL experiment provided a proto-qualification run for satlet environmental and functional testing in addition to meeting ISS safety and operational standards for assembly and deployment.
• Orbital ATK's Cygnus cargo craft CRS-4 approached the International Space Station on Dec. 9, 2015. Cygnus was grappled by the station's robotic arm and berthed to the ISS. The unloading of the cargo into the ISS followed during the next days.
Satlet Technologies in HISatsTM
Small satellites are an exciting technology in the space industry today. For example, over half a dozen private companies have announced plans to build large networks of smallsats to provide remote-sensing imagery data to customers. While smallsats can provide advantages over traditional large satellites, satellites assembled from "building block" cells called satlets add to those advantages. NovaWurks is developing the cellularization of satellite technology as a way to dramatically decrease the cost of new space assets, while also enabling these assets to be incrementally upgradeable and easily repairable. Basically, a small number of nanosat-scale satlets serve as building blocks for assembling a fully functional satellite, analogous to how living organisms are made up of basic cell types. Novawurks has developed satlet technologies in HISatsTM, to be configured and aggregated as reliable, flexible spacecraft for a variety of space purposes. 14)
An initial set of HISat-based experimental missions are either underway or planned for the near future. These experimental missions seek to provide on-orbit verification of the satlet concept, the HISatTM instantiation of that concept, and verification of key payload accommodation features. The spectrum of space access utilized to execute the experimental missions serves to demonstrate the flexibility of the cellularized architecture concept.
1) The SIMPL (Satlet Initial Mission Proofs and Lessons) mission is scheduled to be assembled in space aboard the International Space Station (ISS) enabling a deployment.
2) The eXCITe (eXperiment for Cellular Integration Technology) mission is planned for launch as a pre-launch assembled payload on an ELV (Expendable Launch Vehicle) to be deployed from a SHERPA.
3) The PODSat (Payload Orbital Delivery Satellite) experimental mission aims to utilize HISatsTM after deployment from a host satellite into GTO (Geosynchronous Transfer orbit).
The path forward for HISat-based missions promises to push the envelope into the capabilities once thought only achievable by much larger traditional buses.
A cellular satellite architecture allows the disaggregation of typical space vehicles into as many or as few cardinal pieces (called satlets) as required to achieve cost savings, flexibility, and reliability while maintaining the required mission performance. The term "satlet" is intended to define either a single cellularized subsystem (e.g., a propulsion satlet) or a single standalone satlet-based system. The extent of cellularization can vary between the following two extremes. Single-function satlets incorporate one individual satellite subsystem function per satlet and multiple units are aggregated together to increase the required performance [e.g., spatially distributed miniature RWAs (Reaction Wheel Assemblies) that together provide total momentum control]. Several diverse satlet types are required to complete a space vehicle-equivalent system. System satlets are designed so each satlet constitutes a complete standalone system that contains requisite individual components such as processors, solar cells, batteries, attitude control sensors and actuators, etc., that can be aggregated together to serially increase performance with increased numbers. For this type, identical satlets are aggregated to complete a space vehicle-equivalent system. 15)
System satlets provide advantages in their flexibility to respond to changing requirements, particularly requirement changes occurring late in a mission's life cycle and cost savings achieved by single-type production quantities. NovaWurks has been investigating the cellularization of satellite technology and has developed a hyper-integrated satlet, named HISat, that provides complete satellite functionality in a nanosat-scale package. The HISats can be aggregated and share resources such as electrical power, attitude control sensors and actuators, data processing, etc. With their flexible assembly options resulting in multiple possible configurations, HISats provide a building-block bus, called a PAC (Package of Aggregated Cells) that can conform to and accommodate many different payload sizes and shapes.
The potential benefits to payload designers are obvious. HISats provide an app-based, open-source approach to core resource-sharing cellular firmware that provides for simple user-created applications to coordinate the requisite individual HISat hardware. This enables HISats to be aggregated together informationally so that satlet resource exposure and sharing is transparent to the operation of the system. This critical resource-sharing software provides for basic capability that tailors performance by varying the number of HISats interoperating without skipping a beat.
This aggregation of information adds reliability to a cellularized design. The HISat software approach allows the payload user/developer hands-on design, development, and operation of an app to create a specific functionality desired on a HISat cell (like a cell phone). The application building provides a common building block paired with an easily accessible operating system. The benefit is lower-cost software life cycles because application development can be instantiated, maintained and updated in the cloud by researchers and mission clients alike.
Cellular space systems, like HISats, are an approach, already in space today, for truly low-cost space operations. One proven method of achieving real cost reductions is by mass production, which could reduce costs by two or more orders of magnitude and allow custom tooling and automation to be exploited while their costs are dissipated among units. The satlet cellular approach is a means to reach the promise of increased production to lower costs in the space vehicle business. Satlet production runs of as few as 50 units are predicted to significantly lower cost per satlet. Low production costs, combined with low-cost access to space through flexibility, would enable many space-based services to be competitively offered relative to today's market.
Findings (In all three Product phases)
Design: One imagines the design process as an unalterable, logical, sequence of iterative steps that can be found with some small variations in any systems engineering handbook. A typical sequence of the fundamental systems engineering activities for a space system are: definition of mission goals and concepts, the identification and allocation of required functions, definition of key requirements to achieve the required functionality (and performance), development and execution of design trade studies, iteration of the trade studies and associated operational concepts until one or more system design solutions are found, and then selection of an optimal system. Once this point is reached, the next level of functionality, requirements, and design trade spaces are addressed. Sufficient depth must be reached to support product baselining and cost estimation.
Cellular space system design, while requiring the same basic inputs as a traditional space system, mission goals and concepts, is a very repeatable and flexible process. The functional analysis is minimized as each system satlet provides a broad set of identical functions as resources for the PAC to use. In fact, there is considerable temporal flexibility as to which satlet, or satlets, would provide a particular resource to satisfy a required function. A list of key requirements is still needed, but satisfying those requirements, in many cases, is a matter of sizing the number of satlets required rather than allocating, sizing, and choosing hardware for each subsystem. The trade space for cellular systems becomes focused on the physical configuration of the satlets that comply with the requirements. Mass and power budgets are simplified since each satlet brings a standard unit of mass and power storage and internal usage-based consumption. For a cellular system, there is no need to repeat the design process at successively lower levels (e.g., from system to subsystem to assembly, etc.) as the satlet is the lowest reducible unit.
NovaWurks has exercised the design cycle for its HISat and PACs over 80 times during the last three years. Initial baselines are produced by a small team of two or three engineers in two or three days for a new concept and frequently changes can be accommodated in a single day. Changes are relatively easy to implement, even after the design phase, as occasionally happens due to launch vehicle volume, first fundamental frequency, or center-of-mass requirement updates, and large payload power demands.
Assembly: NovaWurks has gained considerable experience in the assembly area having assembled over 100 HISats to date. Immediately realizable and apparent are the savings achieved in utilizing selected COTS (Commercial Off-The-Shelf) parts and standard materials. In many uses, satlet reliability is not impacted and in cases where it is, the inherent redundancy of a cellular system where many satlets are available to perform multiple functions mitigates the impact to space system reliability.
Satlet assembly is a repeatable process of assembling essentially identical units over and over again. Parts kitting prior to assembly is standardized as well. Lessons are learned on early units, captured in procedures, and applied to subsequent assemblies in an iterative process. While robotics are envisioned to play a role in future satlet assembly lines, NovaWurks is presently using a skilled workforce to perform the assembly tasks. The assembly teams become more efficient in their techniques and task flows due to our human capability to learn and make things better and easier to do. Experience is gained in common failure modes and points, and early intermediate testing can many times be implemented to detect those failures before additional assembly resources and time are wasted. Assembly quality control efforts are focused on the technically difficult areas, resulting in the reduction of satlet acceptance failure rates.
Admittedly, NovaWurks HISat production is still in its infancy where a high learning curve is to be expected, but the results are encouraging in that an estimated 5 x reduction in assembly time has been achieved for the HISat product.
Test: Following assembly, satlets undergo acceptance testing for workmanship. Similar to assembly, testing is also a repeatable process of testing identical units through a standard sequence of tests meant to provide satlet units ready to be assembled into a PAC for flight. Commonality is achieved in required test equipment and test procedures. As with assembly, lessons learned are applied to subsequent testing, resulting in an increasingly efficient and effective test campaign. While presently a skilled workforce is performing the test tasks, a robotic approach has been established to perform future satlet acceptance testing. Testing has allowed experience to be gained in common test setup, execution, and data collection, allowing focus on quality control measures and on those areas resulting in the reduction of satlet acceptance failures due to improper testing.
Initial Cellularized Satellite Experiments
Three experiments have been initiated to test cellular space systems in orbit. All utilize the NovaWurks satlet design, the HISat. One is in orbit while the other two are undergoing ground testing. A brief description of the three space systems and their experimental goals follows.
SIMPL (Satlet Initial Mission Proofs and Lessons)
SIMPL is a six-HISat PAC with two deployable solar arrays that was launched atop a ULA (United Launch Alliance) rocket on December 6, 2015, from the Cape Canaveral Air Force Station in Florida. SIMPL rode in Orbital ATK's Cygnus spacecraft. Berthing with the ISS was completed on December 9, 2015. SIMPL was delivered to the ISS disassembled into its eight components. SIMPL received ISS program office approval for stowage in the ISS and subsequent assembly by an ISS crew member. SIMPL is currently in stowage awaiting ISS crew time for assembly. The SIMPL experiment provided a proto-qualification run for satlet environmental and functional testing in addition to meeting ISS safety and operational standards for assembly and deployment.
SIMPL demonstrates the ability of a cellular space system to be launched unassembled and then be assembled in orbit. The eight SIMPL subassemblies were packaged separately for the launch aboard a Cygnus cargo vehicle. The smaller subassembly packages eased cargo vehicle loading relative to a single package of comparable size and mass. SIMPL was fully certified by NASA for ISS storage, crew assembly, transfer through the Japanese Experiment Module (JEM) to an external platform, and deployment safety via an ISS robotic arm. SIMPL arguably met the most stringent safety requirements of the three experiments since a crewed vehicle was being utilized. SIMPL was designed and tested to use yet a third separation system provided by NanoRacks, the Kaber.
eXCITe (eXperiment for Cellular Integration Technology)
eXCITe is a 14-HISat PAC currently undergoing environmental testing. eXCITe is scheduled to launch on a SpaceX Falcon 9 rocket and be deployed by Spaceflight's SHERPA auxiliary payload accommodation system sometime in Q3 2016. Unlike SIMPL, eXCITe will launch fully assembled in its flight configuration. The eXCITe experiment seeks to provide a proto-qualification run for satlet and PAC environmental and functional testing in an expendable launch vehicle environment. A prime goal of the eXCITe experiment is to demonstrate payload accommodations. The NovaWurks cellular space system utilizes a UDA (User Defined Adaptor) to provide a standard but customizable interface for payloads. eXCITe plans to host a range of payloads to accomplish this goal. To provide payload support for power and high-data-rate communications, eXCITe includes two deployable gimballed solar arrays and two S-band space-to-ground link radios. eXCITe also includes a multi-core processor experiment that has not flown before. From the eXCITe perspective, the multi-core processor operation aims to provide data points on payload thermal management using the UDA. Three radiation science experiments are included in the payload suite. These experiments intend to introduce a longer operational cycle (~24 hours) to eXCITe's accommodation requirements while maintaining specific temperatures to maximize measurement precision.
A frequently touted feature of the cellular architecture is its suitability for on-orbit assembly and reconfiguration. While eXCITe would not be assembled in orbit, it would undergo a reconfiguration. The eXCITe experiment plans to host a free flyer payload which would be deployed via a PSC Mark II motorized lightband. eXCITe's ADCS (Attitude Determination and Control Subsystem) would mitigate attitude deviations from the deployment (the payload is ~20 percent of the total mass), return to its nominal attitude, and resume operations. This deployment would demonstrate the ability of cellular systems to undergo a significant mass-property change and autonomously regain attitude control with new PAC mass properties in effect – a technical capability required for future assembly and reconfiguration missions.
The eXCITe PAC seeks to use two very common standard secondary payload interfaces available in the commercial market, an EELV secondary payload adaptor and a motorized light band separation system. In addition to having the ability to be deployed by a motorized light band, the eXCITe PAC plans to host an additional smaller one to deploy a free-flyer payload itself, with the goal of demonstrating compatibility with both sides of the separation system.
PODSat (Payload Orbital Delivery system Satellite)
PODSat is a four-HISat PAC nearing the start of assembly, integration, and test. PODSat is intended for launch on a to-be-determined expendable launch vehicle in 2017. PODSat is designed to be the free-flying element of the DARPA-funded HPA (Hosted POD Assembly), which seeks to provide a platform (the POD) and a separation mechanism for it be deployed by a host spacecraft. Conceived to take advantage of under-utilized launch vehicle payload mass and reliable, frequent launch opportunities, the initial HPA would be hosted on a geostationary communications satellite, with the PODSat deployment occurring in a sub-synchronous geostationary transfer orbit.
PODSat would provide a demonstration of the ability of cellular architecture to incorporate a structural element, the POD chassis, into a PAC. Similar to the way app-based software architectures allow easy integration of new software, cellular architectures could offer that same feature to a variety of hardware options. — The PODSat experiment would also provide valuable in-orbit data on an orbit environmental regime outside of the first two experiments.
PODSat seeks to utilize a payload delivery system primarily intended to make use of excessive capacity on launch vehicles delivering a primary payload to geostationary orbit. In this case, the HISats would make use of the structural platform and separation system provided by the HPA, which presents configuration requirements very different from eXCITe. The HPA would be hosted in an unused recess on the host spacecraft and not released until a geostationary transfer orbit is attained. Both are very different environments from the eXCITe experiment.
1) "NanoRacks Kaber Mission 1-NovaWurks-Satlet Initial Mission Proofs and Lessons (NanoRacks-NovaWurks-SIMPL-Microsat)," NASA, March 16, 2016, URL: http://www.nasa.gov/mission_pages/station/research/experiments/1982.html
2) "Building blocks to the future," NovaWurks, URL: http://www.novawurks.com/services/conformal-spacecraft-services/
3) "NanoRacks Kaber Mission 1-NovaWurks-Satlet Initial Mission Proofs and Lessons (NanoRacks-NovaWurks-SIMPL-Microsat)," NASA, Oct. 18, 2017, URL: https://www.nasa.gov/mission_pages/station/research/experiments/1982.html
4) "NanoRacks Kaber Microsat Deployer (NanoRacks Microsat Deployer)," NASA, March 16 , 2016, URL: http://www.nasa.gov/mission_pages/station/research/experiments/2049.html
5) Kirk Woellert, "Kaber Small Satellite Deployment System," NanoRacks ISS Workshop, George Washington University, February 17, 2015, URL: http://nanoracks.com/wp-content/uploads/Kaber-Small-Satellite-Deployment-System-Presentation.pdf
6) "Oribital ATK CRS-4 Mision Overview," URL: http://www.nasa.gov/sites/default/files/atoms/files/orbital_atk-crs-4_mission_overview-2.pdf
7) Stephanie Schierholz, Dan Huot, "NASA Cargo Launches to Space Station Aboard Orbital ATK Resupply Mission," NAS Release 15-229, Dec. 7, 2015, URL: http://www.nasa.gov/press-release/nasa-cargo-launches-to-space-station-aboard-orbital-atk-resupply-mission
8) "NanoRacks Deploys Second Kaber-Class Microsatellite This Week, First On-Orbit Assembly," NanoRacks, 27 Oct. 2017, URL: http://nanoracks.com/second-kaber-microsatellite-deployed/
9) Ken Kremer, "Commercial Cygnus Cargo Freighter Departs ISS After Resuming US Resupply Runs," Universe Today, Feb. 19, 2016, URL: http://www.universetoday.com/127478/cargo-freighter-departs-iss-after-resuming-us-resupply-runs/
10) "Orbital ATK Completes OA-4 Cargo Delivery Mission to ISS for NASA," Space Daily, Feb. 23, 2016, URL: http://www.spacedaily.com/reports/Orbital_ATK_Completes-OA_4
11) Information provided by James Greer, Chief Operating Officer of NovaWurks Inc., Los Alamitos, CA, USA.
12) "NovaWurks' Inaugural HISat Experiment Reaches Space," NovaWurks, Dec. 17, 2015, URL: http://www.novawurks.com/novawurks-inaugural-hisat-experiment-reaches-space/
13) Talbot Jaeger, Walter Mirczak, Bill Crandall, "Cellularized Satellites- Initial experiments and path forward," 32nd Space Symposium, Technical Track, Colorado Springs, CO, USA, April 11-14, 2016, URL: http://www.spacesymposium.org/sites/default/files/downloads-Bill%20Crandall--Cellularized
14) Talbot Jaeger, Walter Mirczak, Bill Crandall, "Cellularized Satellites- Initial experiments and path forward," 32nd Space Symposium, Technical Track, Colorado Springs, CO, USA, April 11-14, 2016, URL: http://www.spacesymposium.org/sites/default/files/downloads/Bill-20Crandall--Cellularized
15) Talbot Jaeger, Walter Mirczak, Bill Crandall, "Cellularized Satellites-A Small Satellite Instantiation that Provides Mission and Space Access Adaptability," Proceedings of the 30th Annual AIAA/USU SmallSat Conference, Logan UT, USA, August 6-11, 2016, URL: http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=3363&context=smallsat
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 (email@example.com).