PredGuid+A software was developed to enable a unique numerical predictor-corrector aerocapture guidance capability that builds on heritage Orion entry guidance algorithms. The software can be used for both planetary entry and aerocapture applications. Furthermore, PredGuid+A implements a new Delta-V minimization guidance option that can take the place of traditional targeting guidance and can result in substantial propellant savings.

PredGuid+A allows the user to set a mode flag and input a target orbit’s apoapsis and periapsis. Using bank angle control, the guidance will then guide the vehicle to the appropriate post-aerocapture orbit using one of two algorithms: Apoapsis Targeting or Delta-V Minimization (as chosen by the user).

Recently, the PredGuid guidance algorithm was adapted for use in skipentry scenarios for NASA’s Orion multipurpose crew vehicle (MPCV). To leverage flight heritage, most of Orion’s entry guidance routines are adapted from the Apollo program.

This work was done by Jarret Lafleur of Johnson Space Center. MSC-25199-1

Software Tech Briefs Magazine

This article first appeared in the September, 2013 issue of Software Tech Briefs Magazine.

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