Design and characterization of a printed spacecraft cold gas thruster for attitude control

A three-rotational degree of freedom attitude control system has been developed for the NASA Jet Propulsion Laboratory’s INSPIRE Project by the Texas Spacecraft Laboratory at The University of Texas at Austin. Using 3D plastic printing manufacturing techniques, a cold gas thruster system was created in order to detumble and maintain the attitude of two 3U CubeSats traveling through interplanetary space. A total of four thruster units were produced, including two engineering designs and two flight units. The units feature embedded sensors and millisecond level thrust control while using an inert, commercially-available refrigerant as a propellant. The thrust, minimum impulse bit, and specific impulse performance of the cold gas units was characterized using a ballistic pendulum test stand within a microtorr vacuum chamber. A heating element was used to change the temperature conditions of the propellant and determine the relationship between temperature and performance. The flight units were delivered in January of 2014 and the INSPIRE satellites are expected to launch in the upcoming year.