Faced with the challenging task of shuttling humans to the moon and later to Mars, NASA has tapped Texas Tech University computer scientists to help the agency develop software language that could save it time and money as it builds an abort system for the new Crew Exploration Vehicle.
Beginning in January, NASA’s guidance, navigation and control engineers will work with Texas Tech scientists as they develop a prototype Onboard Abort Executive – decision-making software intended to aid the crew and flight controllers in determining the safest abort decision should a failure occur in flight.
The abort executive will monitor the crew exploration vehicle for problems, predict its abort capability and determine an appropriate strategy for doing so.
The prototype will use a declarative language called SequenceL developed at Texas Tech. The language, created by Texas Tech computer science department chair Dr. Daniel Cooke, will be used to test the abort executive’s behavior before NASA commits to building costly onboard software. This should result in fewer errors and reduce overall development costs.
Recent NASA workshops have indicated that current software development practices and computer languages – even with evolutionary changes – may not be rapid or dependable enough for future missions. This is especially true as the agency prepares for its new call to send humans to the moon again and later to Mars.
Creating software prototypes and system requirements that would be easier to develop and understand while requiring less coding would allow the engineers to build and deploy new systems more rapidly – something that could be necessary as unexpected situations arise during lunar or Mars exploration missions.
Texas Tech already has been working with members of Johnson Space Center’s Guidance, Navigation and Control organization to apply SequenceL language to abort software that NASA had developed for its Shuttle Cockpit Avionics Upgrade Project, a cockpit display upgrade for NASA shuttles.
The new project will determine whether SequenceL should be used to develop requirements and create software prototypes for the new Crew Exploration Vehicle.
This collaborative project will be led by Howard Hu, Johnson Space Center’s Aeroscience and Flight Mechanics Division chief engineer for Crew Exploration Vehicle Guidance, Navigation and Control. It will also involve Cooke, faculty member Dr. J. Nelson Rushton and Texas Tech – Abilene doctoral candidate Robert Watson, who will relocate to Houston for six months.
In related research, an A-Prolog language, created by Texas Tech computer science professor Dr. Michael Gelfond in collaboration with Houston-based space operations company United Space Alliance, is a system that quickly finds work-around plans in response to even multiple failures of the shuttle’s Reaction Control System. It can be used in a similar fashion for other types of onboard systems.
A Concrete State Machine Language, developed by Rushton, is a language to tie A-Prolog and SequenceL into existing onboard systems. If this succeeds, it will result in a more general, integrated and formal approach to the implementation of different types of systems, including guidance, navigation and life support, Cooke said.
The Crew Exploration Vehicle will be a manned spacecraft capable of ferrying astronauts and scientists on extended space missions after the existing shuttle fleet is retired.
CONTACT: Daniel Cooke, chairman, Department of Computer Science, Texas Tech University, 806-742-1193, daniel.cooke@ttu.edu
Howard Hu, chief engineer for Crew Exploration Vehicle Guidance, Navigation and Control, Johnson Space Center Aeroscience and Flight Mechanics Division, 281-483-8154.
Cory Chandler, Texas Tech Media Relations, cory.chandler@ttu.edu
