The vehicle relies on computerized control and monitoring for
DPS software is divided into two major groups: system software and
Five identical computers aboard the orbiter control vehicle systems.
Computing functions for all mission phases requires about 400,000
words of computer memory.
CRT Display System
Displays on the flight deck allow onboard monitoring of systems,
software processing and manual control for crew data and software
The GPC complex requires an accurate time source because its software
uses GMT to schedule processing.
Data Bus Network
Network is divided into specific groups that perform specific functions.
DPS MDMs convert and format serial digital GPC commands into
separate commands for various vehicle system hardware.
Send signals to arm and safe pyrotechnics during SRB/ET separation.
Bus Isolation Amplifiers
Interfacing devices for the GSE/LPS and SRB MDMs.
Flight Control The fifth GPC, loaded with different software,
provides backup in case primary GPCs fail.