Autonomous ASCENT Abort Planning Applied to Military and Civilian Space Launch Vehicles
Mark Jackson, Howard Hu · 2004
Future military and civilian launch systems will require on-board mission management software to reduce operational costs, allow simultaneous operation of multiple vehicles, and maximize safety and the probability of mission success. When problems occur during the critical ascent phase of the mission, onboard autonomous software can reduce risk by commanding correct abort options and determining desirable landing targets. Ascent abort decision-making may be complex when tradeoffs between mission success, vehicle retrieval and crew survivability are considered. This is particularly true for multi-stage vehicles whose individual elements must either return to a landing site, or be disposed of safely. In order to manage this complexity, abort scenarios are decomposed temporally into a hierarchy of activities and sub-activities. Associated with each activity is a software agent, which performs monitoring, diagnosis, planning and execution of the activity or mission element. Background is provided on the use of hierarchical planning techniques to create a tree of these “activity agents.” These techniques are then applied to two contrasting space vehicles: a two stage unmanned military reusable launch vehicle, and a manned capsule on an expendable launch vehicle. The design process and lessons learned derived from these projects are illustrated in the examples and conclusions.