The infrared Astronomical Satellite IRAS is equipped with an on-board computer system that takes care of vital satellite functions as attitude control, ground dialogue, and execution of the observation programs. Therefore an important purpose of the IRAS system tests was the Verification and Validation of the on-board software. The test configuration was largely determined by the attitude control system. Provision of representative inputs for the attitude control system tests, required orbital simulation. The attitude control functions resident in ROM were exercised extensively in closed loop (satellite dynamics model in Ground Checkout computer), providing a flexible environment for combined 'black and white box' testing. The less critical but more accurate RAM software had to be exercised in open loop (attitude sensor stimuli precomputed on a mainframe). The large amount of RAM software permitted only functional ('black box') testing. The close loop method was confirmed to be the most desirable.
Verification and Validation of IRAS (Infrared Astronomical Satellite) On-Board Software
1983
11 pages
Report
No indication
English
Unmanned Spacecraft , Astronautics , Space Launch Vehicles & Support Equipment , Satellite attitude , Attitude control , Checkout , Computerized simulation , Reliability , Foreign technology , Infrared astronomy satellite , Airborne/spaceborne computers , Computer software , Computer program verification , Read only memories , Random access memory , Validation