Satellite Drag Model for Near Real Time Operation

ABSTRACT: Michigan Aerospace Corporation, in cooperation with the University of Michigan"s Department of Atmospheric, Oceanic, and Space Sciences, will refine existing upper atmospheric models and apply them to the problem of predicting satellite drag. The primary goal of this Phase 1 project is to run a fully validated version of University of Michigan"s Global Ionosphere Thermosphere Model (GITM) in a near real-time setting, driven by a real-time version of the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) technique, allowing the most accurate specification of the high-latitude electric fields and particle precipitation possible. Real time measurements of solar X-Rays will be utilized to help specify the solar irradiance. Validation will be conducted by running AMIE and GITM for 2001-2006, which are part of the CHAMP and GRACE satellite mission time-frame, allowing statistical comparisons to be made. Further, the possibility of running an ensemble of simulations will be explored, allowing for uncertainty and variability in the drivers to be accounted for. This work will be applied to the problem of atmospheric drag and its effect on satellite orbital elements. BENEFIT: The technology resulting from the successful conclusion of this STTR project will assist the Air Force with an improved model of upper atmospheric effects on satellites, allowing a more accurate ephemeris of orbiting objects in the Air Force"s space catalog. This will be of help to all the branches of the military, which have elements that depend on accurate knowledge of satellite positions and passages. Also, the Air Force and NASA both have an interest in knowing with as much accuracy as possible the paths of orbiting satellites to predict possible conflicts well in advance and to forecast orbital decay as accurately as possible, amongst other concerns with satellites and orbital debris.