Powered descent guidance strategy and algorithms for mars landing using supersonic retropropulsion

Supersonic retropropulsion (SRP) has not yet been utilized for planetary Entry, Descent and Landing (EDL) although its use has been theorized since the 60s. EDL trajectories with SRP enable landing larger masses on Mars than those possible using aerodynamic decelerators only. For manned missions to Mars, SRP will be a necessary technology, given the high ballistic coefficients that the entry vehicles require. Trajectories using SRP as the only means of terminal deceleration possess specific characteristics that require a tailored strategy and guidance algorithms, both of which are outlined in this paper.