AAS 98-147

ENTRY TRAJECTORY DISPERSIONS DUE TO UNCERTAINTIES IN THE MARS ATMOSPHERE

G. E. Peterson - The Aerospace Corp.; R. H. Bishop - University of Texas at Austin

Abstract

As greater accuracies become required for manned missions to Mars, it is necessary to identify those areas of atmospheric error that drive the total error for entry trajectories. To accomplish this task, the current study examines the dispersions for a proposed Mars 2001 ballistic entry profile using the Mars Global Reference Atmosphere Model developed by the Marshall Space Flight Center to accomplish this task. Error sources surveyed include: thermosphere errors, atmospheric waves, dust storms, global climatic change, and a new wind error model based upon the Dryden aerodynamic model modified for the martian atmosphere. Comparison with the usual COSPAR standard deviations is also examined.

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