Ada and real-time robotics: lessons learned

The Supervisory Telerobotics Laboratory (Steler) at the Jet Propulsion Laboratory (JPL) has developed a prototype telerobotic system to demonstrate the type of technology that will be used aboard Space Station Freedom Although the concept of telerobotics for space exploration is not new, the Steler system broke new ground in its demonstration of the feasibility of a local-remote architecture, including ground-remote control, for space applications. A remote space environment poses some interesting computational challenges to ground-remote control of space applications. A remote site has limited computation facilities, is burdened by minimal bandwidth and by round-trip communication delays of as much as 8 seconds, and yet is expected to respond quickly, predictably, and with recoverability to any anomalous situation. Additional design constraints are imposed by NASA´s limitations on software, including on-board programs for the robot, being uploaded to the remote site without prior flight qualification. The authors discuss the use of Ada to meet the computational requirements of this project.<>