(Georgia Institute of Technology, 2007-04-27)
Christian, John Allen
Accurate post-flight reconstruction of a vehicle’s trajectory during entry into a planetary
atmosphere can produce a wide array of valuable information. The data collected through
the reconstruction of entry, descent, and landing (EDL) system performance enables the
quantification of performance margins for future systems. Beyond the engineering
knowledge gained through trajectory reconstruction, the results may also be used by
planetary scientists to generate an accurate atmospheric profile. A computer tool was
developed to facilitate the rapid analysis of data gathered during entry. Emphasis was
placed on making the tool flexible and capable of easily incorporating different types of data.
These data are used to provide an accurate reconstruction through the use of an Extended
Kalman Filter (EKF). In its present form, the filter propagates the mean state forward using
a three degree-of-freedom dynamic model and is capable of handling data from
accelerometers and altimeters. The tool is validated against previous trajectory and
atmosphere reconstructions that were performed for the Mars Pathfinder mission.