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The Fifteen-Year Attitude History of the Wide Field Planetary Camera 2 Radiator and Collection Efficiencies for Micrometeoroids and Orbital DebrisAn examination of the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC-2) radiator assembly was conducted at NASA Goddard Space Flight Center (GSFC) during the summer of 2009. Immediately apparent was a distinct biasing of the largest 45 impact features towards one side of the radiator, in contrast to an approximately uniform distribution of smaller impacts. Such a distribution may be a consequence of the HST s attitude history and pointing requirements for the cold radiator, or of environmental effects, such as an anisotropic distribution of the responsible population in that size regime. Understanding the size-dependent spatial distribution of impact features is essential to the general analysis of these features. We have obtained from GSFC a 15 minute temporal resolution record of the state vector (Earth Centered Inertial position and velocity) and HST attitude, consisting of the orientation of the velocity and HST-sun vectors in HST body coordinates. This paper reviews the actual state vector and attitude history of the radiator in the context of the randomly tumbling plate assumption and assesses the statistical likelihood (or collection efficiency) of the radiator for the micrometeoroid and orbital debris environments. The NASA Marshall Space Flight Center s Meteoroid Environment Model is used to assess the micrometeoroid component. The NASA Orbital Debris Engineering Model (ORDEM) is used to model the orbital debris component. Modeling results are compared with observations of the impact feature spatial distribution, and the relative contribution of each environmental component are examined in detail.
Document ID
20100008460
Document Type
Conference Paper
Authors
Anz-Meador, Phillip D. (Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
Liou, Jer-Chyi (NASA Johnson Space Center Houston, TX, United States)
Cooke, William J. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Koehler, H. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 25, 2013
Publication Date
January 1, 2010
Subject Category
Instrumentation and Photography
Report/Patent Number
JSC-CN-19843
Meeting Information
38th COSPAR Scientific Assembly(Bremen)
Distribution Limits
Public
Copyright
Other