Tech Briefs

Simulating Avionics Upgrades to the Space Shuttles

Cockpit Avionics Prototyping Envi - ronment (CAPE) is a computer program that simulates the functions of proposed upgraded avionics for a space shuttle. In CAPE, pre-existing space-shuttle-sim - ulation programs are merged with a commercial-off-the-shelf (COTS) display- development program, yielding a package of software that enables highfidelity simulation while making it possible to rapidly change avionic displays and the underlying model algorithms. The pre-existing simulation programs are Shuttle Engineering Simulation, Shuttle Engineering Simulation II, Inter active Control and Docking Simulation, and Shuttle Mission Sim - ulator playback.

The COTS program — Virtual Ap pli - cation Prototyping System (VAPS) — not only enables the development of displays but also makes it possible to move data about, capture and process events, and connect to a simulation. VAPS also enables the user to write code in the C or C++ programming language and compile that code into the end-product simulation software. As many as ten different avionicupgrade ideas can be incorporated in a single compilation and, thus, tested in a single simulation run. CAPE can be run in conjunction with any or all of four simulations, each representing a different phase of a space-shuttle flight.

This program was written by Daniel Deger and Kenneth Hill of Johnson Space Center and Karsten E. Braaten of United Space Alliance. MSC-23453-1/15-1