Eric Pearce, University of Arizona Steward Observatory; Harrison Krantz, University of Arizona Steward Observatory; Adam Block, University of Arizona Steward Observatory; Brad Sease, Computational Physics, Inc; Mitchell Kirshner, University of Arizona System and Industrial Engineering; Kris Rockowitz, University of Arizona Steward Observatory
Keywords: near-IR, visible, orbital debris, characterization, SL-12 RB, UKIRT, MMT, WFCAM, UIST
Abstract:
The characterization of deep space debris poses a significant challenge in SSA. In order to be most useful, characterization should be performed quickly and under non-ideal observational conditions, generally using non-resolved techniques. The use of multi-color photometry and the resultant color indices potentially can rapidly discriminate between debris and intact space objects such as rocket bodies and satellites. However, these studies are not well informed by high resolution spectra of these same objects due to the lack of prior measurements with large astronomical telescopes.
During 2020, our team will measure an ensemble of rocket-bodies, intact spacecraft, and cataloged debris with both the UKIRT WFCAM (5-color near-IR photometry) and the UKIRT 1-5 ?m Imager-Spectrometer (UIST). This data set will provide us with overlapping broadband IR colors, and high-resolution spectra in the same color bands. Combined with previous WFCAM measurements in 2016-2017, and previous high-resolution visible band spectra with the MMT telescope, this is a unique data set. Our targets are carefully chosen to include a mix of objects with known compositions that will allow the development and evaluation of techniques to interpret our broadband near-IR photometry while being informed with the higher resolution spectra from UIST. The rocket bodies selected for study include the SL-12 fourth stage rocket bodies (SL-12 RB) measured in our previous 5-color survey. The intact payloads are chosen from satellites using the Boeing HS-376 busses. These objects exteriors are dominated by solar panels which completely cover the spacecraft. Four different generations of solar panels were used over the twenty years of HS-376 development, with the earliest models using shallow function n/p silicon cells, and later models using GaAs/Ge single junction and GaInP2/GaAs/Ge dual junction panels. Both the SL-12 RB and Boeing HS-376 serve as ideal test objects of known composition for controlled studies.
In this paper, our team presents a prelude of our 2020 observing campaign. The analyzed data, supplemented by our previous measurements with WFCAM and the MMT telescope, will be presented in a future paper.
We will evaluate the efficacy of using near-IR color-indices to discriminate space debris and other objects from small solar-panel covered satellites. We will also describe refined techniques to measure near-IR colors with WFCAM and create a more efficient observing protocol. Finally, this data set will permit a denser sample of photometric and spectral observations over the entire range of available phase angles during a single collection. The augmented data set yields a more informed analysis of near-IR color indices.
Date of Conference: September 15-18, 2020
Track: Non-Resolved Object Characterization