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Proceedings Paper

Proton ullage motor observations as possible precursors to explosions in space
Author(s): Paul D. Maley; J. Lynn Palmer
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Paper Abstract

Two optical observation campaigns during 1999 and 2000 were conducted to monitor the optical characteristics of the Proton 4 ullage motor population located in mainly geostationary transfer orbits about the earth. This study attempted to physically characterize the intact ullage motors and those that have exploded in space using conventional large aperture binocular optics and 3rd generation image intensified video (commonly employed for non-military astronomical observation) in order to determine if optical signatures could reveal evidence as to which motors might be candidates for explosion. We find that some motors do not spin down through normally expected damping; explosions do not consistently result in the catastrophic destruction of the parent body involved; accelerations in the rotation rates of some intact ullage motors have been discovered; some fragmentations do not result in an increase in rotation of the surviving parent as might be expected. No conclusive evidence was obtained that could lead to positively identifying precursors for future explosion. Yet, through statistical methodology we determined that there is a strong probability of additional explosions until the majority of motors launched between 1982 and 1996 decay from orbit. We estimate the probability of at least one of 46 ullage motors currently in orbit exploding before decay is greater than 0.9999. The threat of explosions is not expected to be mitigated by natural decay of all candidate exploders for at least 50 years.

Paper Details

Date Published: 27 December 2001
PDF: 12 pages
Proc. SPIE 4490, Multifrequency Electronic/Photonic Devices and Systems for Dual-Use Applications, (27 December 2001); doi: 10.1117/12.455439
Show Author Affiliations
Paul D. Maley, NASA Johnson Space Ctr. (United States)
J. Lynn Palmer, NASA Johnson Space Ctr. (United States)

Published in SPIE Proceedings Vol. 4490:
Multifrequency Electronic/Photonic Devices and Systems for Dual-Use Applications
Paul S. Idell; Andrew R. Pirich; Stanley R. Czyzak; Paul L. Repak; Paul S. Idell; Stanley R. Czyzak, Editor(s)

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