By Adam Koenig July 12, 2016
SLAB Ph.D. student, Adam Koenig, is working at Johnson Space Center (JSC) this summer under the direction of Dr. Chris D’Souza as part of his NASA Space Technology Research Fellowship. While at JSC, Koenig will use his experience in angles-only navigation to refine requirements for the near-field rendezvous phase of Orion’s proposed Distant Retrograde Orbit Missions such as the Asteroid Redirect Mission. Koenig was awarded the prestigious fellowship in response to a proposal titled: “Angles-Only Navigation System for Nano-Satellites” submitted under the supervision of SLAB director Simone D’Amico in the fall of 2014. With the support of this award, Koenig will develop, integrate, and validate an angles-only navigation system for nano-satellites or CubeSats. Work conducted under this award has already resulted in a paper presented at the 26th AAS/AIAA Space Flight Mechanics Meeting by fellow SLAB Ph.D. student Joshua Sullivan. This paper describes a navigation filter that is able to estimate the relative position and velocity of a target spacecraft based on angle measurements only, without imposing the maneuver requirements of previous approaches.
Angles-only navigation is a key enabling technology for a broad range of mission applications in on-orbit servicing and space situational awareness because the only required sensor is a monocular camera. A star tracker, which is standard equipment on nearly all modern spacecraft, is sufficient for this purpose. Angles-only navigation uses a sequence of bearing angle measurements to estimate the relative position and velocity of a target space resident object. Because this technique uses only the light reflected by the target, it enables spacecraft to safely navigate in the vicinity of non-cooperative targets such as defunct spacecraft and pieces of debris. Koenig’s miniaturized system will enable relative navigation experiments to be conducted with smaller spacecraft, reducing mission costs.
In addition to his work on angles-only navigation, Koenig is also working on the SLAB Miniaturized Distributed Occulter/Telescope (mDOT) mission concept. The primary objective of the mDOT mission is to validate the performance of the optical and guidance, navigation, and control subsystems before deployment of a large-scale, multi-billion dollar mission such as NASA’s New Worlds Observer or EXO-S. The secondary objective of the mDOT mission is to directly image an exozodiacal dust disk in the ultraviolet spectrum. This image could be used in conjunction with observations in the visible or infrared spectra from ground-based observatories to better understand the composition of these disks. If successful, the mDOT mission would dramatically increase confidence in distributed occulter/telescope technologies and motivate efforts toward a larger mission capable of imaging earth-like planets. ”