This payload developed by NMSU engineers was recently launched on the
UP Aerospace SpaceLoft rocket from Spaceport America. (NASA photo)
(December 8, 2015) A research project led by New Mexico State University Professor Ou Ma that began in 2008 holds scientific, military and commercial promise for the growing use of satellites. The innovative technology aims to enable spacecraft to dock with satellites for rescue or servicing, thereby increasing the lifespan of these pricey crafts that can spin off and become space junk.
“The inertia properties, such as mass, location of mass center and moments of inertia, of a spacecraft can change in orbit due to fuel consumption, hardware re-configuration, payload deployments or payload capture. When this happens, the spacecraft’s control system needs to know the changes of inertial properties to maintain proper control of the spacecraft,” said Ma, who is the first recipient of the John Kaichiro Nakayama and Tome Miyaguchi Nakayama Professorship for Research Excellence.
Ma’s Inertial Property Algorithm Verification (IPAV) Project algorithm to identify the inertia properties of a spacecraft incorporates the novel use of an onboard robotic arm. A large advantage of using a robotic arm to identify inertia, over existing methods, is that it solar powered, requiring no fuel, and measures velocities only (as opposed to measuring forces and accelerations by the existing methods).
NMSU Mechanical and Aerospace Engineering Professor Ou Ma
has been leading a team of students since 2009 to develop an algorithm
to determine changes in inertia for in-orbit spacecraft.
But testing and validation requires the system to float freely and rotate arbitrarily in a 3D-space without gravity and therefore, prohibitively difficult to do on the ground. Several other different methods for spacecraft inertia identification have also been proposed, but none has as of yet been tested in a real microgravity environment.
“Our approach is to reach this goal incrementally,” said Ma. The group has twice tested the system in an aircraft parabolic flight that provided 10-20 seconds of continuous microgravity time.
The algorithm has also been tested twice in suborbital flight, providing 150-200 seconds of microgravity time, most recently as a payload on the launch of the UP Aerospace SpaceLoft rocket from Spaceport America in November 6, 2015.