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AR&D Background

Since the days of the Apollo Moon Missions, NASA has worked tirelessly to develop and improve a variety of sensor suites, designed to collect data about the conditions and environment of space flight. During manned and unmanned missions, these sensors have provided critical decision-making data crucial to Mission success. Sensors are especially crucial during the spacecraft maneuvers for Rendezvous and Docking (R&D). In the course of developing these sensors NASA realized that a system was needed for Automated Rendezvous and Docking (AR&D) to act as a potential backup system for manned missions or as a primary capability on unmanned missions.

It was during the Orbital Maneuvering Vehicle Program of the mid 1980s when it became clear that the development of a rendezvous sensor would be critical to the creation of an AR&D System. In the late 1980s work was begun on developing a video-based rendezvous sensor capable of providing the relative position and attitude of the spacecraft, relative to a docking port.

In the 1990s a first generation rendezvous sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on Space Shuttle flights STS 87 and again on STS 95, proving the concept of a video-based sensor. Advances in both video and signal processing technologies and the lessons learned from the two successful flight experiments provided a baseline for the development of a new generation of video-based rendezvous sensor. The Advanced Video Guidance Sensor (AVGS) has greatly increased performance and additional capability for longer-range operation.

With the recent advent of NASA’s Exploration Initiative, slated to return to Lunar Exploration and eventual human exploration of Mars, NASA’s work with AR&D has been elevated in importance. This is due to the fact that future Lunar and Mars exploration will rely heavily on the assembly of large elements, both crewed and uncrewed, in low earth orbit and beyond. At present, R&D technology requires extensive human intervention for flight operations and ground control; however, data latency for operations at Mars precludes ground involvement for proximity operations and becomes very problematic for lunar operations. Therefore, an AR&D system, with less reliance on human participation (both ground and crew) is considered to be necessary to accomplish the goals of the Exploration Initiative.

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