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Since 1986 NASA has been developing a telerobotic system as a part of the Flight Telerobotic Servicer (FTS) Project at Goddard Space Flight Center. The project was formed to meet the national objectives of identifying and developing technologies for automation and robotics. The overall approach is to adapt current teleoperational and robotic technologies into a lightweight, dexterous telerobotic device that could operate efficiently and safely in space and that would evolve into an autonomous space robot. The concept behind this device is that it (1) operate in space, a much less structured and more hostile environment than industrial robots normally operate in and (2) perform varied dexterous tasks which increase in complexity with time. The design must also allow for growth and increased capabilities as new technologies become available. These top-level system goals significantly influenced system design, architecture, controls implementation, and manipulator packaging design. If the FTS is to be considered as a credible tool for work in space, its fundamental building blocks must be tested in space. An early development test flight (DTF-1) was conceived to fly as an attached payload on the Shuttle in order to validate the FTS hardware design. While the funding for the FTS was eliminated in September 1991, the DTF-1 system design has been completed with major flight hardware elements in different stages of fabrication and qualification. Safety was a design driver for the DTF-1. System safety engineering was implemented with the system safety requirements and design criteria established by NASA's National Space Transportation System (NSTS) Program and defined in the Safety Policy and Requirements for Payloads Using the Space Transportation System, NSTS, 1700.7B. Satisfying these safety requirements presented significant challenges to the system designers. In an effort to capture some of the knowledge gained from the program, this paper gives an overview of the DTF-1 mission, describes the system design, and describes the safety requirements and safety features that were incorporated. It also presents the `lessons' that were learned during the design and early development stages.
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