Lyon B. King (Michigan Technological University Department of Mechanical Engineering – Engineering Mechanics), Jacob A. LaSarge (Michigan Technological University Department of Mechanical Engineering – Engineering Mechanics)
Keywords: Non-Resolved Object Characterization
Abstract:
The Oculus-ASR is a 70-kg-nanosatellite specifically designed to advance USAF space situational awareness by providing calibration opportunities and validation techniques for AMOS’s telescopic non-resolved object characterization program. This paper will describe the design and capabilities of the Oculus-ASR, its concept of operations, and report on its initial ground optical characterization. Nearly every object orbiting the Earth, when viewed using all but the largest ground-based telescopes, appear as unresolved point sources of light. Although these unresolved objects seem to be featureless, it may be possible to determine characteristics related to an objects attitude and/or rotation rate by analyzing the spectral and temporal content of reflected sunlight off of the object. For instance, a faceted rotating object may produce a periodic cycle of bright glints when viewed from the ground. Alternatively, a spectrally distinct surface coating on the object may be detectable from the ground using a spectrometer. The design of Oculus-ASR uses specific shape properties as well as spectrally distinct materials on the spacecraft in order to emphasize, to the ground observer, changes in light intensity and spectral characteristics when viewed from the ground. Additionally, the nanosatellite has the ability to change its shape (and therefore its visible characteristics) while in orbit. It also possesses 3-axis control capability, allowing the Oculus-ASR to present different structural features and maneuver states to the ground observer. In order to accurately recognize the visible properties of the vehicle while in space, the nanosatellite has been optically characterized in an AFRL ground facility to determine reflective signatures that can be expected on orbit. Once on orbit, the Oculus-ASR will be monitored by ground-based telescopes and these observations will be reconciled against the truth attitude data recorded by the Oculus-ASR during various overpasses. Operations of the Oculus-ASR will require coordination between AMOS, AFRL, and Michigan Tech University’s (MTU) ground operators. Aside from controlling the vehicle, ‘truth’ data, overpass scheduling, and maneuver planning will serve as key points of communication between all organizations involved.
Date of Conference: September 11-14, 2012
Track: Non-Resolved Object Characterization