NASA Selects Green Propulsion Projects for SBIR Phase II Awards

CubeSat
CubeSat

Continuing our look NASA’s Small Business Innovation Research Phase II program, we examine three proposals for advanced propulsion technologies that the agency has selected for awards.

NASA selected the Busek Company, of Nantick, Mass., for two SBIR Phase II awards. One involves the development and testing of a flight-weight, 5N-class green monopropellant thruster. The second involves the development of a high-throughput nominal 100-W Hall effect thruster.

The space agency also selected a proposal submitted by CU Aerospace of Champaign, Ill., to develop its CubeSat High Impulse Propulsion System (CHIPS). The company is also using a non-toxic propellant in the system.

The three projects were among 108 proposals that NASA selected for SBIR Phase II funding. The awards last no more than two years. Funding can be up to $750,000 per project or up to $1.5 million per project, depending upon the type of award made.

Busek says that its 5N-class green mono-propellant thruster represents a significant improvement over other propulsion systems.

“The most important feature that sets this thruster apart from other similar devices will be the use of an innovative, long-life catalyst,” the company said in its proposal. “This proprietary catalyst, constructed without any bed plate or ceramic substrate, has the potential to suppress catalyst-related performance degradation problems that often plague mono-propellant thrusters.”

“Potential NASA applications of both the 5N and 100N green monopropellant thrusters include missions to low Earth orbits and beyond,” the document reads. “Near-term examples are the Geostationary Operational Environmental Satellite (GOES) at GEO, the Wide Field Infrared Survey Telescope (WFIRST) at GEO, the International X-ray Observatory (IXO) at L2, and the next Mars robotics mission scheduled for 2020 launch.”

Busek’s 100-W Hall effect thruster project is aimed at a smaller class of satellites.

“The proposed 100-W thruster fills a void between existing micro-propulsion options and existing low power Hall thruster systems,” according to the project summary. “The system provides the benefits of electric propulsion (specific impulse, delta-V) to small, low cost spacecraft, a market which is presently under-served. The proposed 100-W thruster is especially well sized for spacecraft weighing 20 to 200-kg. Integration with nano-spacecraft (<20 kg) is also feasible.”

Under its CHIPS proposal, CU Aerospace will design, fabricate and ground test a nanosat propulsion subsystem using non-toxic R134a propellant.  The company has teamed up with VACCO Industries to develop the propulsion system.

“The CHIPS thruster family provides a compact, non-hazardous, dual-use propulsion technology solution with projected low cost, that will be made available in sizes that can meet the differing needs of users in NASA, DOD, industry, and academia for CubeSat and nanosatellite missions,” according to the proposal summary.

PROPOSAL SUMMARY
Busek Company, Inc.

Nantick, MA

Proposal Title: Lifetime Improvement of Large Scale Green Monopropellant Thrusters via Novel, Long-Life Catalysts
Subtopic Title: In-Space Propulsion Systems

Estimated Technology Readiness Level (TRL) at beginning and end of contract: 
Begin: 4
End: 5

TECHNICAL ABSTRACT

Busek proposes to develop and life-test a flight-weight, 5N class green monopropellant thruster in Phase II. The most important feature that sets this thruster apart from other similar devices will be the use of an innovative, long-life catalyst. This proprietary catalyst, constructed without any bed plate or ceramic substrate, has the potential to suppress catalyst-related performance degradation problems that often plague monopropellant thrusters. The Phase II thruster in essence will be a matured version of the highly-successful Phase I prototype, with the addition of high-temperature nozzle material. To further demonstrate the design’s scalability, a 100N class thruster will be developed and demonstrated at the end of Phase II.

POTENTIAL NASA COMMERCIAL APPLICATIONS 

Potential NASA applications of both the 5N and 100N green monopropellant thrusters include missions to low Earth orbits and beyond. Near-term examples are the Geostationary Operational Environmental Satellite (GOES) at GEO, the Wide Field Infrared Survey Telescope (WFIRST) at GEO, the International X-ray Observatory (IXO) at L2, and the next Mars robotics mission scheduled for 2020 launch. As with state-of-the-art reaction control rockets Busek’s green monopropellant thrusters are radiation-cooled and restart-able, making them a simple yet reliable propulsion option. In addition, the green propellant’s storability and low-toxicity will be attractive for NASA’s future manned spaceflight. Without the need for excessive safety measures, overall operational cost for the manned missions will be reduced.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS 

The market size for green monopropellant thrusters is very large. In addition to NASA, all branches of the military are interested in deploying them for tactical or in-space applications. The non-toxic storable feature of the propellant enables preloaded propulsion systems that can accommodate rapid launch operations. Because Busek’s thrusters have the potential for extended life without performance degradation, developers of GEO communication satellites will likely consider them for both reaction control and primary propulsion. This versatility will help broaden market access. A successful Phase II program will lead to direct sales or licensing of the thrusters and the associated catalyst technology.

TECHNOLOGY TAXONOMY MAPPING 

  • Fuels/Propellants
  • Maneuvering/Stationkeeping/Attitude Control Devices

PROPOSAL SUMMARY
Busek Company, Inc.
Nantick, MA

PROPOSAL TITLE: High Throughput Hall Thruster for Small Spacecraft

SUBTOPIC TITLE: Propulsion Systems

Estimated Technology Readiness Level (TRL) at beginning and end of contract: 
Begin: 3
End: 5

TECHNICAL ABSTRACT

Busek is developing a high throughput nominal 100-W Hall Effect Thruster. This device is well sized for spacecraft ranging in size from several tens of kilograms to several hundred kilograms. It could be fueled by either xenon or iodine. The latter yields performance like xenon, but stores at low pressure and high density, make it especially attractive for volume limited spacecraft. The available specific impulse will be 1400-1600-s. The target thruster efficiency is 45%. At 100-W and 1500-s, the thrust will be 6.1 mN. The lifetime of the thruster may exceed 10,000 hours, yielding a throughput of greater than 14.9 kg.

In Phase I, the thruster was designed. Design considerations included efficiency, specific impulse, temperature, lifetime, mass, volume, and cost. Careful attention to the magnetic field resulted in a “magnetically shielded” shape, which should minimize or entirely eliminate ion wall losses. Testing with a nominal 200-W thruster showed the feasibility and desirability of both permanent magnets and a diamond discharge channel. Permanent magnets save mass, volume, and power. Diamond reduces ion sputtering by 50% with respect to conventional materials.

In Phase II, the 100-W thruster and a compact cathode to accompany it will be manufactured, tested, and improved. Performance, lifetime, and plume properties will be evaluated. Testing will include both xenon and iodine. Year 2 development will focus on maximizing throughput. Integrated testing will include a compact, low cost, power processing unit. The technology will reach TRL 5.

The program is responsive to NASA topic S3.03, Propulsion Systems. Both the “Electric Propulsion” and “Micro-Propulsion” sub-topics are relevant. The proposal also addresses several of NASA’s Grand Challenges, including Efficient In-Space Transportation, Space Debris Hazard Mitigation, and Economical Space Access.

POTENTIAL NASA COMMERCIAL APPLICATIONS

The proposed 100-W thruster fills a void between existing micro-propulsion options and existing low power Hall thruster systems. The system provides the benefits of electric propulsion (specific impulse, delta-V) to small, low cost spacecraft, a market which is presently under-served. The proposed 100-W thruster is especially well sized for spacecraft weighing 20 to 200-kg. Integration with nano-spacecraft (<20 kg) is also feasible. The first NASA application could be a small technology satellite demonstration satellite fueled by xenon or iodine propellant. Other near term applications could include drag-makeup and formation flying.

The size, low alpha (kg/kW), and simplicity of Hall thrusters make them ideal for many other applications. These include orbit raising and lowering, de-orbiting, station-keeping, inclination changes, and interplanetary transfers. Destinations could include asteroids, comets, dwarf planets, outer planets, etc. In such missions, the thruster could function either by itself or in conjunction with a larger Hall thruster. Still other applications could include a cargo delivery vehicle originating in LEO or at the ISS, or a small electric upper stage.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS

Hall thrusters are attractive for commercial and military spacecraft due to their high performance, relatively small size, low mass, and relatively low cost. Continuous thrust functions for small, power-limited spacecraft in LEO would include orbit insertion and maintenance, in-space maneuvering, orbit-raising, and de-orbiting. The thruster is appropriate for spacecraft as small as 6 – 12 U in size. Applications for geosynchronous spacecraft would include station-keeping and repositioning. In pulsed mode, the thruster could provide high precision impulse bits for station-keeping, attitude control, precision positioning, and constellation maintenance.

An iodine fueled system could provide an “off the shelf” option for operationally responsive spacecraft. The military has a need for satellites that are both operationally responsive to launch command and operationally responsive to the war fighter on-orbit. The ORS office is proposing a paradigm shift from the traditional architecture to a more flexible “plug and play” architecture. For this class of spacecraft, a low power Hall thruster fueled by iodine is very attractive because it can be stored as a solid at low temperature and sub-atmospheric pressure, allowing pre-fueled long term storage of the propulsion system until a responsive space need arises.

TECHNOLOGY TAXONOMY MAPPING

  • Ceramics
  • Fuels/Propellants
  • Maneuvering/Stationkeeping/Attitude Control Devices
  • Models & Simulations (see also Testing & Evaluation)
  • Passive Systems
  • Simulation & Modeling
  • Spacecraft Main Engine

PROPOSAL SUMMARY
CU Aerospace, LLC

Champaign, IL

PROPOSAL TITLE:  CubeSat High Impulse Propulsion System (CHIPS)

SUBTOPIC TITLE:Propulsion Systems

Estimated Technology Readiness Level (TRL) at beginning and end of contract:
Begin: 4
End: 6

TECHNICAL ABSTRACT

CU Aerospace proposes to perform design, fabrication, and ground test validation of a nanosat primary propulsion subsystem using non-toxic R134a propellant. Our approach, called CubeSat High Impulse Propulsion System (CHIPS), leverages CU Aerospace’s very high efficiency warm-gas variant of an innovative resistojet that significantly boosts the performance of standard cold-gas systems with the existing Micro Propulsion System (MiPS) thruster technology development by our team partner, VACCO Industries. The MiPS system has been tested to 200,000 cycles without any technical issues, demonstrating excellent reliability. A 1.5U CHIPS subsystem, using non-toxic R134a propellant, is a compact thruster system having a total impulse of 680 N-s and a fully throttleable continuous thrust of 30 mN. The subsystem also includes an R134a 3-axis cold-gas attitude control system to replace reaction wheels. Approximately 25 W of primary power is required from a lithium-ion battery included in the 1.5U package. This low-cost subsystem demonstration will pioneer a family of nanosat propulsion systems, which will become available to the CubeSat and nanosatellite communities for orbit change, de-orbit, precision maneuvering, and drag makeup missions.

POTENTIAL NASA COMMERCIAL APPLICATIONS

CHIPS technology supports the NASA Roadmap for In-Space Propulsion Systems, nonchemical propulsion. CubeSats and nanosatellites with CHIPS would enable a number of different significant missions for low Earth orbits including orbit raising, orbit phasing, and deorbiting. The drag makeup capability of CHIPS would allow low altitude endo-atmospheric orbits, permitting onboard sensors to operate at lower altitude. Using a cold-gas mode, CHIPS also has the capability for precision position adjustments, enabling missions requiring station keeping, formation flying, and docking. CHIPS would improve mission affordability for multiple CubeSats, since several CubeSats with CHIPS could be launched from a single low-cost booster and maneuvered to other orbits, then later deorbited. Note that CHIPS is easily scalable to smaller or larger sizes (total impulses), depending on mission and payload requirements, by changing the tank volume. Battery size can either be scaled, or kept the same size if recharging between thrust events is practical for the mission.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS

The CHIPS thruster family provides a compact, non-hazardous, dual-use propulsion technology solution with projected low cost, that will be made available in sizes that can meet the differing needs of users in NASA, DOD, industry, and academia for CubeSat and nanosatellite missions.

TECHNOLOGY TAXONOMY MAPPING

  • Extravehicular Activity (EVA) Propulsion
  • Fuels/Propellants
  • Maneuvering/Stationkeeping/Attitude Control Devices
  • Spacecraft Main Engine