Computer Based Control of the Superfluid Helium On-Orbit Transfer Space Shuttle Experiment

Abstract

NASA’s Superfluid Helium On-Orbit Transfer (SHOOT) project is a Shuttle-based cryogenic experiment designed to acquire data on the properties of superfluid helium in micro-gravity with a 1992 manifested flight date. Two software development projects are ongoing at Ames Research Center to support the goals of the SHOOT experiment. These are the SHOOT Command and Monitoring System (CMS) and the SHOOT Aft Flight Deck Operating System (AFDos). The SHOOT Command and Monitoring System software will provide a real time highly interactive interface for the SHOOT principal investigator to control the experiment and to analyze and display its telemetry. Important features of the CMS include: redundancy to guarantee archiving of telemetry; real time calibration of raw data; display of data in a graphical format including real time plotting; and full commanding capabilities. Aft Flight Deck software (AFDos) for the SHOOT experiment is comprised of several monitoring programs that give an astronaut Mission Specialist on-orbit visibility into SHOOT systems and an intelligent rule based system (AFDEX) that will control a helium transfer without ground intervention. This expert system will provide intelligent process control, diagnosis, and error recovery capabilities for the transfer of superfluid helium between two dewars in the Shuttle’s cargo bay. In addition payload simulation software is being developed to aid in software testing and shuttle flight crew training.