A man-in-the-loop computer facility has been created using a digital computer, display terminal,and space vehicle flight computer to enable programmers to check out flight programs in a simulated space flight environment. The simulation requires a real time multi-programmed environment, which is supplied by a control system capable of scheduling programs on 32 levels of priority interrupt as well as answering demands for service at the display terminal. A special interface device permits visibility and control of the flight program as it executes in the flight computer. On-line inputs from the programmer at the display terminal and outputs from data collection and reduction routines to the display screen are executed in real time. The Flight Software Development Laboratory has proved to be very useful in reducing program preparation time and increasing flight program confidence.
