System level verification applying the Space Shuttle experience to the Space Station

The applicability of the verification process for the Shuttle guidance, navigation and control (GNC) and data management system (DMS) for the development of the Space Station are described. Shuttle avionics hardware/software integration was delayed to finalize the hardware design before detailed definition and testing of the software. A block diagram is provided of the flight simulation laboratory used to test the GNC programs before flight data were available. The Station will have distributed computers, unlike the Orbiter, and will only be assembled fully in space. Standardized integration simulation test equipment are being defined to guide the development of hardware and software. The simulation capability may become part of nominal in-flight operations to initiate new capabilities as they are added to the Station. The Station GNC and DMS systems development will be somewhat simplified relative to those of the Shuttle because ascent and reentry will not be considered for the Station.