Air force 16. 2 Small Business Innovation Research (sbir) Phase I proposal Submission Instructions

However, with the advent of the use of electric propulsion for orbit raising the additional power that the solar array could deliver could reduce trip time from low earth orbit to the operational orbit of the satellite.

To solve this problem the solar array interface must be capable of delivering all of solar array power at the spacecraft bus voltage at beginning of life and end of life conditions. Potential methods for addressing this challenge include, but are not limited to; higher efficiency cell designs, alternate cellular arrangements, dynamic topology adjustment, high-efficiency reconfigurable charge management circuitry, concepts in soft-defined power-aware and degradation-aware distribution architecture possibilities.

The solar array interface should be capable of operation in a Low Earth Orbit (LEO) for 5 years and in a Geosynchronous Earth Orbit (GEO) or Medium Earth Orbit (MEO) for 15 years after storage on the ground for 5 years. It should function after 500 kRad (Si) total dose, be immune to dose rate and single event latchup, and not upset at a single event LET lower than 20 Mev/mg/cm2.

PHASE I: Perform preliminary analysis and conduct trade studies to validate performance for the solar array interface. Using breadboard hardware verify related performance information in support payoff estimates.

PHASE II: Fabricate and deliver engineering demonstration unit. Show the flexibility of delivering reliable power with the solar array at various load points. Identify radiation impacts upon components of the string converter.

PHASE III DUAL USE APPLICATIONS: Technology developed will be applicable to all military and commercial space platforms. Expected benefits include 20% to 50% increase in beginning of life solar array power.

REFERENCES:

1. Edward J. Simburger, Simon Liu, John Halpine, David Hinkley, J. R. Srour, and Daniel Rumsey, The Aerospace Corporation and Henry Yoo, Air Force Research Laboratory, Pico Satellite Solar Cell Testbed (PSSC Testbed), Presented at the 4th World Conference on Photovoltaic Energy Conversion, Wailoloa, Hawaii. May 7-12, 2006.

2. Edward J. Simburger, Daniel Rumsey, David Hinkley, Simon Liu and Peter Carian, The Aerospace Corporation, Distributed Power System for Microsatellites, 31st IEEE Photovoltaic Specialists Conference, Lake Buena Vista, FL. 3-7, January, 2005.

3. Kasemsan Siri and Calvin Truong, “Performance Limitations of random Current-Sharing Parallel-Connected Converter Systems & Their Solution,” APEC'98, Anaheim, California, pp. 860-866, Vol 2, February 14-19, 1998.

4. Kasemsan Siri, “Study of System Instability in Current-Mode Converter Power Systems Operating in Solar Array Voltage Regulation Mode,” APEC’2000, New Orleans, Louisiana, pp.228-234, Vol 1, February 6-10, 2000.

5. Kasemsan Siri, Vahe A. Caliskan and C.Q. Lee, "Maximum power tracking in parallel-connected converter systems," IEEE Trans. on Aerospace and Electronics Systems, vol. 29, no. 3, pp. 935-945, July 1993.

KEYWORDS: Peak Power Tracker, Solar Array, Parallel Power Conversion, Distribution and Control, Solar Array Regulation

TECHNOLOGY AREA(S): Space Platforms

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.

OBJECTIVE: Develop and demonstrate decreased mass, volume and power requirements for spacecraft liquid chemical propellant storage and feed hardware.

DESCRIPTION: Typical propellant storage and feed systems for spacecraft using liquid chemical propulsion comprise compressed helium or nitrogen driving the propellant from the storage tank. Mission requirements will drive the choice of blow down or regulated pressure feed, likewise, the choice of feed will further drive the type of propellant management device. Also common for hydrazine monopropellant systems, the driving pressure gas and propellant will be within the same tank separated by an elastomeric diaphragm. Also, it is frequently necessary to provide some sort of environmental control for the propellant storage tank to ensure the propellants do not freeze or fall to sub-nominal temperature for thruster operation. These systems are proven for reliability and have long flight legacies, however, they are not free of concerns and there remains opportunity for improvement of the design.

Pressurized tankage presents a significant logistical and cost footprint in the regards to component qualification or verification, acquisition lead time, and spacecraft processing operations. Where monopropellant thrusters are used, catalyst poisoning is always of concern. Though standards for the purity of hydrazine as well as for preparation of the elastomer diaphragm materials, such as AFE-332, that the hydrazine would be continuously contacting within a diaphragm tank are well established, introduction of contaminating substances acquired from the hydrazine or diaphragm leaching may have potential to alter thruster delivered performance due to catalytic poisoning. Similar concerns are also present for emerging advanced green monopropellant formulations.

Other limitations faced with liquid propulsion systems on board spacecraft relate to impulse variability and determination of propellant remaining. In blow down systems, the change in delivered performance of the thruster due to decreasing feed pressure must be mapped in order to be able to determine thrust commands to accomplish desired maneuvers. For missions with large delta-V requirements, significant amounts of propellant will be required driving need of large compressed gas tanks reducing mass and volume available for payload. Liquid chemical thrusters that can deliver variable thrust from a compact configuration, such as combined functionality of low thrust monopropellant and high thrust bipropellant modes, for different mission phases have been developed and are commercially available.

Of interest is a liquid propellant storage and feed system that does not grow in volume and component manufacturing risk with propellant throughput (such as state of the art compressed gas approaches) that also mitigates typical concerns associated with reliability, repeatability, and contamination. Envisioned applications are for thrusters in the range of ~0.25 lbf to ~5.0 lbf, with design knowledge to scale up and be able to support to the 100 lbf level. Minimum impulse bit performance repeatability and predictability that is superior or, as a minimum, equivalent to the state of the art is desired.

Performance and capability advantages to all type of spacecraft platforms from extremely volume limited applications such as Cubesats up to large scale, long life systems such as GPS should be assessed and presented.

Developmental effort should include a physics based understanding in terms of a mathematical expression; capturing details of power requirements, geometry, material make-up, duty cycle, and propellant throughput range as a function of relevant parameters.

Energy requirements should be bounded within today’s nominal satellite bus architecture capabilities.

Additional considerations should include streamlined manufacturing process with high yield and minimal quality assurance required. Estimates of storage life and guidance to maximize storage should also be considered, minimal storage requirements are desired. Approaches with applicability to both state of the art and emerging green propellant formulations are encouraged.

The thruster technology should be capable of supporting a 15-year mission in GEO or Medium Earth Orbit (MEO) and 5 years in Low Earth Orbit (LEO) after ground storage of 5 years.

PHASE I: Demonstrate a feasibility concept and accompanying base model approach that shows path to meet manufacturability and performance metrics stated. The effort should clearly address and estimate propulsion system inert weight and overall flight system impacts as well as model and manufacturing technical challenges.

PHASE II: Demonstrate proof of concept with flight scaled components in relevant environment. Propulsion system inert weight and flight system impacts shall be optimized from those estimated in Phase I. Leading model and manufacturing technical challenges shall be retired or have a clearly defined path to mitigation.

PHASE III DUAL USE APPLICATIONS: The Offeror shall develop viable demonstration cases in collaboration with the government or the private sector. Follow-on activities are to be sought aggressively throughout all mission applications within DoD, NASA, and commercial space platforms by Offeror.

REFERENCES:

1. Ballinger, I.A.; Lay, W.D.; Tam, W.H., “Review and History of PSI Elastomeric Diaphragm Tanks”, AIAA 95-2534, 31st AIAA/ASME/SAE/ASEE Joint Propulsion Conference, San Diego, CA, July, 1995.

2. Ballinger, A.; Sims, D., “Development of an EPDM Elastomeric Material for use in Hydrazine Propulsion Systems”, AIAA 2003-4611, 39th AIAA Propulsion Conference, Huntsville, AL July 21, 2003.

3. Honse, J.P.; Bangasser, C.T.; Wilson, M.J., “Delta-Qualification Test of Aerojet 6 and 9 lbf MR-106 Monopropellant Hydrazine Thrusters for Use on the Atlas Centaur Upper Stage during the Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS) Missions”, AIAA 2009-5481, 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Denver, CO August, 2009.

4. Owens, B.; Cosgrove, D.; Sholl, M.; Bester, M., “On-Orbit Propellant Estimation, management, and Conditioning for THEMIS Spacecraft Constellation”, AIAA 2010-2329, SpaceOps Conference, Huntsville, AL, April, 2010.

5. United States Patent 5,417,049.

KEYWORDS: Spacecraft Propulsion, Chemical Propulsion, Propellant Storage, Propellant Feed system, Pump, Blow Down, Thruster

AF162-009

TITLE: Electric Propulsion for Dual Launch

TECHNOLOGY AREA(S): Space Platforms

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.

OBJECTIVE: Develop high-thrust solar electric propulsion technologies that enable/enhance mission capabilities and dual manifest launch opportunities for national security space assets.

DESCRIPTION: Pervasive electric propulsion (EP) technologies greatly enhance in-space maneuverability and spacecraft payload capacity for many DoD missions, such as transfer to Geostationary Earth Orbit (GEO), when compared to liquid chemical propulsion [1]. Satellites with EP as primary propulsion have lower propellant mass requirements, which provide cost and schedule advantages with launch vehicle step-down, dual launch, or mixed manifest capability on existing launch vehicles to reduce the number of satellite launches. This has significant benefits for DoD and commercial applications [2,3,4]. State-of-the-art EP on the Air Force Advanced Extremely High Frequency (AEHF) satellites have demonstrated orbit transfer from geosynchronous transfer orbit (GTO) to GEO, however this required multiple months of thruster firing time due to low thrust levels, which are limited by the available on-board power. Thus, maximizing thruster efficiency and thrust to power (T/P) levels are necessary to reduce orbit transfer time, specifically to minimize duration through the Van Allen radiation belts [5]. Existing technologies, such as high-power Hall thrusters, have demonstrated reduced efficiency when operating at peak T/P and must operate at a de-rated power, further reducing overall thrust [1].

This solicitation seeks research on EP system technologies capable of greater than 70% efficiency over the range of 1400 to 2000 seconds specific impulse (Isp), corresponding to T/P levels of 109 to 76 millinewtons per kilowatt (mN/kW), respectively. This efficiency includes power processing and ancillary losses, such as cathode flow or electromagnet power requirements. Proposal solutions may be either ideas for advancing existing thruster technologies or the development of new concepts, such as high-power electrospray propulsion. Specific power of the thruster and power processing should be less than 6 kg/kW. A representative power level for this technology is 3-10 kW, though subscale demonstrations may be conducted at lower power levels to accommodate cost-effective research activities. The full propulsion system (thruster, power processing unit & propellant feed) should define a clear path for transition to national security space applications in the proposal.

The thruster technology should be capable of supporting a 15-year mission in GEO or Medium Earth Orbit (MEO) and 5 years in Low Earth Orbit (LEO) after ground storage of 5 years.

PHASE I: Perform proof-of-concept analysis and experiments that demonstrate the feasibility of the high performance electric propulsion concept. End TRL 2 to TRL 4.

PHASE II: Measure performance and plume characteristics of breadboard hardware to demonstrate program goals for the high performance electric propulsion concept. Breadboard hardware will be evaluated on thrust stands at AFRL, and achieve TRL 5 at the end of Phase II activities. Deliverables include breadboard hardware, preliminary cost analyses, and full performance analysis with comparison to state-of-the-art EP.

PHASE III DUAL USE APPLICATIONS: Transition of a mature high performance electric thruster will reduce satellite orbit transfer time and enable/enhance dual launch or mixed manifest capabilities. Additional transition partners may include NASA and U.S. manufactured large GEO communications satellites.

REFERENCES:

1. Brown, D. L., Beal, B E., Haas, J. M., “Air Force Research Laboratory High Power Electric Propulsion Technology Development,” IEEEAC Paper #1549, Presented at the IEEE Aerospace Conference, Big Sky, MT, March 3-7, 2009.

2. “Commercial Space Transportation Forecasts,” Report, Federal Aviation Administration, Office of Commercial Space Transportation and the Commercial Space Transportation Advisory Committee, May 2013.

3. Sargent, Anne-Wainscott, “SpaceX Effect Fuels Efficiency Push in Launch Services Market,” Via Satellite, July 17, 2014 (www.satellitetoday.com).

4. Feuerborn, S. A., Neary, D. A., Perkins, J. M., “Finding a Way: Boeing’s All Electric Propulsion Satellite,” AIAA-2013-4126, 49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, July 14-17, 2013.

5. Observations of the Earth and Its Environment: Survey of Missions and Sensors, 4th Edition, Herbert J. Kramer, Springer Science & Business Media, 2002.

KEYWORDS: Electric Propulsion, Dual Launch, Dual Manifest, Thrust to Power, Orbit Transfer

AF162-010

TITLE: Flexible Electric Propulsion for Resilient Spacecraft

TECHNOLOGY AREA(S): Space Platforms

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.

OBJECTIVE: Develop low-cost, flexible solar electric propulsion technologies that enable/enhance resilient mission capabilities and disaggregated satellite architectures.

DESCRIPTION: Electric propulsion (EP) is a pervasive space technology that greatly enhances in-space maneuverability compared to liquid chemical propulsion [1]. Satellites with EP have lower propellant mass requirements for the same maneuver, which reduces the overall satellite wet mass, enables more on-board propellant for additional maneuvers or extended lifetime, or increased payload mass capability [1, 2]. These capabilities enable numerous advantages for satellite resiliency, including dual launch or mixed manifest for functional disaggregation [3], and flexible positioning to enhance satellite options for multi-orbit disaggregation. To this end, a high efficiency EP technology compatible with chemical propellants could be paired with a chemical thruster to produce highly flexible and efficient multi-mode propulsion (MMP) system. An agile MMP system with shared propellant and tanks reduces system complexity and increases risk mitigation redundancy by enabling flexible and optimal utilization of propellant between the EP and chemical thruster system for in-space maneuvers, including orbit transfer, repositioning, station-keeping, attitude control, and disposal. Realizing these advantages requires innovative solar electric propulsion technologies with high efficiency and high thrust when operated with lightweight, molecular propellants used in chemical propulsion, such as hydrazine or advanced “green” energetic monopropellant formulations [4]. To date, EP technologies have not met the performance and lifetime requirements needed for agile MMP capabilities [5, 6].

This solicitation seeks research on electric thruster technologies capable of greater than 110 mN/kW over a specific impulse from 1000-1500 seconds. Proposal solutions may be either ideas for improving existing thruster technology or the development of new concepts. Specific power of the thruster and power processing electronics should be less than 6 kg/kW. A representative power level for this technology is 1-5 kW per thruster, though demonstrations may be conducted at different power levels or with simulated propellant to accommodate cost-effective research activities. The full propulsion system (thruster, power processing unit & propellant feed) should define a clear path for transition to national security space applications in the proposal.

The thruster technology should be capable of supporting a 15-year mission in GEO or Medium Earth Orbit (MEO) and 5 years in Low Earth Orbit (LEO) after ground storage of 5 years.

PHASE I: Perform proof-of-concept analysis and experiments that demonstrate the feasibility of the high performance electric propulsion concept.

PHASE II: Measure performance and plume characteristics of breadboard hardware to demonstrate program goals for the high performance electric propulsion concept. Breadboard hardware will be evaluated on thrust stands at AFRL, and achieve TRL 5 at the end of Phase II activities. Deliverables include breadboard hardware, preliminary cost analyses, and full performance analysis with comparison to state-of-the-art EP.

PHASE III DUAL USE APPLICATIONS: Transition of flexible electric propulsion will enhance satellite resiliency with increased in-space maneuverability and reduced propellant mass. Transition may include NASA and the U.S. commercial large GEO communications satellites.

REFERENCES:

1. Brown, D. L., Beal, B E., Haas, J. M., “Air Force Research Laboratory High Power Electric Propulsion Technology Development,” IEEEAC Paper #1549, Presented at the IEEE Aerospace Conference, Big Sky, MT, March 3-7, 2009.

2. Feuerborn, S. A., Neary, D. A., Perkins, J. M., “Finding a Way: Boeing’s All Electric Propulsion Satellite,” AIAA-2013-4126, 49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, July 14-17, 2013.

3. “Resiliency and Disaggregated Space Architectures,” White Paper, AFD-130821-034, Air Force Space Command, Released August 21, 2013.

4. Spores, R. A., Masse, R., Kimbrel, S., McLean, C., “GPIM AF-M315E Propulsion System,” AIAA-2013-3849, 49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, July 14-17, 2013.

5. Frisbee, R. H., “Evaluation of High-Power Solar Electric Propulsion Using Advanced Ion, Hall, MPD, and PIT Thrusters for Lunar and Mars Cargo Missions,” AIAA-2006-4465, 42nd AIAA Joint Propulsion Conference, Sacramento, CA, 9-12 July, 2006.