Early in the 1980's NASA plans to orbit a Large Space Telescope using Space Shuttle as the launch platform. This orbiting telescope will permit scientists to observe the universe with a clarity never before attained through ground systems inhibited by the Earth's atmosphere. Current design goals indicate that the Telescope is to be designed for a fifteen year life span with the capability for on-orbit maintenance and, if required, earth return for servicing and refurbishment. Thus, NASA has decided to design a spacecraft for on-orbit EV manned maintenance thereby anticipating significant overall program cost savings. The design for orbital EV maintenance reaches across nearly every subsystem providing an excellent opportunity for complete human factors (crew systems) participation from system concept through design, integration, test, and ultimate operation. This shift in approach to on-orbit maintenance has resulted in major challenges such as designing for suited astronaut access to all subsystem equipment elements, minimization of contamination, handling of extremely sensitive instruments and their transfer through and within minimum volumes, development of translation techniques, incorporation of built-in crew work aids recognizing weight/volume limits and accomplishing the maintenance cycle within timelines imposed by mission, suit, and changeout constraints. These and other considerations will be discussed, alternative solutions presented, and recommendations made with particular reference to those factors which must be undertaken early to assure a timely and fundamentally sound crew systems program.
