Hydra Rendezvous and Docking Sensor System

U.S. technology to support the Crew Exploration Vehicle (CEV) rendezvous and docking operations was developed by NASA and supporting industry during an extensive research and development program conducted during the 1990\´s and early 2000 time frame at the Marshall Space Flight Center. Development and demonstration of a rendezvous/docking sensor was identified early in NASA\´s AR&D Program as the critical enabling technology that allows automated proximity operations and docking. A first generation rendezvous/docking sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on 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/docking sensors. The Advanced Video Guidance Sensor (A VGS) has greatly increased performance and additional capability for longer-range operation. A Demonstration Automatic Rendezvous Technology (DART) flight experiment was flown in April 2005 using AVGS as the primary proximity operations sensor. Because of the absence of a docking mechanism on the target satellite, this mission did not demonstrate the ability of the sensor to control docking. Mission results indicate that the rendezvous sensor operated successfully in "spot mode" (2 km acquisition of the target, bearing data only) but was never commanded to "acquire and track" the docking target.