Subcategory: Astronomy and Astrophysics
Cherish A. Prickett - University of Rhode Island
In March 2012, the National Aeronautics and Space Administration (NASA) cataloged the ten worst satellite breakups. These breakups released hundreds of thousands of particles of orbital space debris, thousands of which were large enough to be cataloged and tracked. Space debris includes manmade objects that no longer serve a useful purpose, including non-functional spacecraft and launch vehicle stages. The 2009 Iridium-Comos collision alone resulted in a large amount of debris, with roughly 1,700 pieces still in orbit as of March 2012. With 94% of all cataloged objects within Earth’s orbit being categorized as orbital space debris, the problem of debris cluttering Earth’s orbital atmosphere becomes more concerning due to the risk of collision in space missions and damage to current satellites, including commercial communication satellites. Many of these satellites reside in Geosynchronous Earth Orbit (GEO). In studying the debris found in GEO, our goal is to understand the surface characteristics of the debris including the variability in brightness, estimating the size, and verifying the material of the debris. We present an analysis of debris that were the result of the 1992 fragmentation of a Titan IIIC orbital launch vehicle transtage launched in 1968. It was characterized using aperture photometry and the suite of tools found within the Image Reduction and Analysis Facility (IRAF) software system. The debris was imaged in April 2012 using the Small and Moderate Aperture Telescope System (SMARTS) consortium’s 0.9-m telescope at the Cerro Tololo Inter-American Observatory (CTIO) in La Serena, Chile. These data included approximately 1,700 object and standard star images of five pieces of tracked and cataloged debris. The images were taken using the Johnson-Cousins BVR and I filters to reveal properties of the debris in different wavelength bands. Preliminary results show a periodic nature in the light curves on some nights during the observations, which infers rotation of irregular shaped debris with non-uniform materials. In contrast, the same rotation was not seen in the light curves during subsequent nights, indicating a change in the nature of the rotation and/or orientation of the object. The calculated colors of the debris do not match any of the spacecraft materials for which we have color information at this time. Future work will include constraining the size of the unresolved space debris by assuming a range of albedos.
Funder Acknowledgement(s): This project was conducted in the framework of the CTIO Research Experience for Undergraduates (REU) Program, which is supported by the National Science Foundation under grant AST-1062976.
Faculty Advisor: Catherine Kaleida,