Small Business Innovation Research/Small Business Tech Transfer
Milliarcsecond Small Spacecraft Attitude Control System
Project Description
Busek proposes to develop a highly modular attitude control system (ACS) which will provide orders of magnitude improvements over state-of-the-art alternative ACS for CubeSats. The low inertia of CubeSats combined with vibrational disturbances and resolution limitations of state-of-the-art ACS presently limit body-pointing and position control accuracy. Busek’s electrospray thrusters aboard the ESA LISA Pathfinder spacecraft recently demonstrated precision control at nm scales; this work extends that success to CubeSat platforms. Passively fed electrospray thrusters are highly compact, including fully integrated propellant supplies, and are capable of ~100nN thrust control at 10’s of nN noise. Thrust can be throttled over >30x, to a scalable maximum of 10’s of uN. These traits, combined with >900s Isp enable these systems to replace traditional reaction wheel ACS; improving pointing error from arcsecs to 10’s of milliarcsec. This work addresses critical development gaps, in both thruster-heads and a multi-axis power processing unit, presently gating the technology. Phase I established a thorough baseline dataset, which confirmed critical performance metrics, and established development gaps. Phase II will emphasize total impulse goals and thruster system maturation. Task 1 will execute design modifications developed in Phase I and augment existing test capabilities. Task 2 will identify and address impulse limiting mechanisms. Task 3 will develop and validate solutions to known mechanical risks and incorporate evolved requirements into a low-mass engineering-model thruster module. Task 4 will focus on power processing development, targeting a control architecture which maximizes the precision control capabilities of the technology and serves multiple thruster heads. These efforts will converge in Task 5 where engineering model thruster performance will be rigorously evaluated over a complete life demonstration.
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Anticipated Benefits
NASA's 2015 technology roadmap recognizes the importance of electrospray propulsion to attitude control, formation flight and positioning of small spacecraft. Specific applications benefiting from precision pointing include astronomical missions, planetary (including earth) observations, laser communications and space situational awareness. The greatly improved body pointing afforded by the proposed technology would present designers with previously unobtainable levels of stability and resolution; permitting both lower cost/complexity realization of existing needs and enabling new objectives in these fields. Applications benefiting from highly precise position control include formation flights and missions requiring disturbance free flight. This includes drag-compensation enabling enhanced mission durations at low orbit altitudes below 350km. The proposed work would allow small spacecraft, CubeSats and larger, to benefit from precision control in a manner akin to the NASA Disturbance Reduction System (DRS), featuring Busek thrusters, aboard the LISA Pathfinder mission. Developing a highly featured PPU and controller would also enable other DRS sub-components, such as GSFC contributed control algorithms, to be applied over a wider NASA mission portfolio. Moreover, through replacing wheels or expanding wheel de-saturation capacity in deep space missions, the proposed work would decrease spacecraft size/complexity and enable new missions.
Compact propulsion systems that are scalable in both thrust and deltaV without loss of performance are an enabling technology for CubeSat missions and therefore have numerous commercial applications. Potential non-NASA customers include, international partners (such as ESA), the DoD and commercial EO missions. The modular nature of the proposed technology would enable customized applications that simultaneously meet customer needs in precision pointing and disturbance compensation; therefore, maximizing the commercial applicability of the technology. The virtual elimination of vibrational jitter while superseding reaction wheel precision presents a clear competitive advantage. The proposed system would be applicable to a myriad of CubeSat sizes from ~3U to >25kg; the market size is therefore large and includes rapidly growing platforms. Commercial applications may include optical communication alignment for high bandwidth up/downlinks or precision pointing during EO missions in low orbits. De-orbiting applications are particularly relevant to new LEO EO and telecommunication initiatives. International consensus is forming around the need for orbital debris management, which poses risks to functioning space assets. The proposed system could enable precision attitude control and a de-orbit means from a single integrated system; thus reducing the burden of integrating a de-orbit system. More »
Compact propulsion systems that are scalable in both thrust and deltaV without loss of performance are an enabling technology for CubeSat missions and therefore have numerous commercial applications. Potential non-NASA customers include, international partners (such as ESA), the DoD and commercial EO missions. The modular nature of the proposed technology would enable customized applications that simultaneously meet customer needs in precision pointing and disturbance compensation; therefore, maximizing the commercial applicability of the technology. The virtual elimination of vibrational jitter while superseding reaction wheel precision presents a clear competitive advantage. The proposed system would be applicable to a myriad of CubeSat sizes from ~3U to >25kg; the market size is therefore large and includes rapidly growing platforms. Commercial applications may include optical communication alignment for high bandwidth up/downlinks or precision pointing during EO missions in low orbits. De-orbiting applications are particularly relevant to new LEO EO and telecommunication initiatives. International consensus is forming around the need for orbital debris management, which poses risks to functioning space assets. The proposed system could enable precision attitude control and a de-orbit means from a single integrated system; thus reducing the burden of integrating a de-orbit system. More »
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Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Busek Company, Inc. | Lead Organization |
Industry
Women-Owned Small Business (WOSB)
|
Natick, Massachusetts |
Goddard Space Flight Center
(GSFC)
|
Supporting Organization | NASA Center | Greenbelt, Maryland |
Primary U.S. Work Locations
-
Maryland
-
Massachusetts
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