<title>Common architecture in the flight software for STIS and NICMOS</title>

Abstract

The near infrared camera and multi-object spectrometer (NICMOS) and the space telescope imaging spectrograph (STIS) are next-generation orbital replacement instruments for the Hubble Space Telescope (HST). Ball Aerospace Systems Group is currently designing and building these instruments for the National Aeronautics and Space Administration. Substantial components of the flight software for these two instruments are being designed in common in order to save development costs and to make in-orbit commanding and maintenance of the flight software easier. The majority of the flight software (FSW) for both NICMOS and STIS is embedded within the electronics of the instruments. This paper begins with an overview of the HST-environment in which the embedded FSW for both STIS and NICMOS executes. The paper then describes: (1) the common electronics environment in which the FSW executes, (2) the FSW development environment, (3) the FSW real-time environment, (4) the method for in-orbit commanding of instrument operations via macros, (5) the method for gathering analog hardware engineering data, (6) the method for commanding the STIS CCD detectors and the NICMOS detectors, (7) the structure and management of the science data buffer, (8) fault management, (9) the collection of diagnostic data, (10) the capabilities for uplinking new FSW code and data once the instruments are in orbit, and (11) instrument-specific software executing in the NASA Standard Spacecraft Computer (NSSC-1), external to STIS and NICMOS.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.