(Georgia Institute of Technology, 2017-02)
Sorgenfrei, Matt; Stevenson, Terry; Lightsey, E. Glenn
One challenge facing the developers of CubeSats that operate in deep space is
that magnetic torque rods cannot be used for unloading the momentum stored in
reaction wheels. Rather, this task is performed by a system of thrusters. While a
wide variety of attitude control thrusters have been deployed on larger spacecraft,
there remain very few examples of such systems being used on CubeSats.
The upcoming BioSentinel mission, under development at NASA Ames Research
Center, is an example of a CubeSat-class spacecraft that requires thrusters
for momentum management. A new 3D-printed cold gas thruster was developed
for this application. This paper will describe the test campaign that was completed
for the engineering development unit (EDU), and will present a variety of
preliminary results describing the performance characteristics of the thruster.
The test campaign for the propulsion system EDU was carried out in partnership
with members of the In-Space Propulsion Branch at Glenn Research Center in
Cleveland, OH.
(Georgia Institute of Technology, 2016-02)
Sorgenfrei, Matt; Stevenson, Terry; Lightsey, E. Glenn
A distinguishing feature of deep space CubeSats is that they require some form of propulsion system, either for orbital maneuvering operations, spacecraft momentum management, or both. However, the comparatively short lifecycle for these missions, combined with the mass and volume restrictions that are attendant with the CubeSat form factor, make the integration of propulsion systems one of the highest-risk aspects of the entire mission. There are a limited number of facilities around the country that can support accurate testing of thruster systems that generate milli-Newtons of thrust, and the cost associated with handling and transportation of traditional propellants can be prohibitive for many CubeSat mission budgets. As a result, many deep space CubeSats are considering propulsion systems that are either at a fairly low technology readiness level or which will be integrated after a truncated test campaign. This paper will describe the propulsion system architecture selected for the BioSentinel mission, a six-unit CubeSat under development at NASA Ames Research Center. Bio-Sentinel requires a propulsion system to support detumble and momentum management operations, and this paper will discuss the integration of a third-party propulsion system with an Ames-built CubeSat, as well as the test campaign that is underway for both quality control and requirements verification purposes.