STS-128 on-orbit demonstration of the TriDAR targetless rendezvous and docking sensor

Neptec has developed a vision system for autonomous rendezvous and docking in space that does not require the use of cooperative markers, such as retroreflectors, on the target spacecraft. The system uses an active TriDAR 3D sensor along with embedded model based tracking algorithms to provide, out of the box, 6 degree of freedom (6DOF) relative pose information in real-time. The TriDAR (triangulation + LIDAR) sensing technology combines active triangulation and Time-of-Flight (TOF) ranging techniques within a single optical path. This design takes advantage of the complementary nature of these two technologies to provide optimal 3 dimensional data from several kilometers all the way to docking. A thermal imager is also included to provide bearing information at long range. In partnership with the Canadian Space Agency (CSA) and NASA, Neptec has space qualified the TriDAR vision system and integrated it onboard the Space Shuttle Discovery to fly as a Detailed Test Objective (DTO) on the STS-128 mission. The objective of the TriDAR DTO mission was to demonstrate the system's ability to perform acquisition and tracking of a known target in space autonomously and provide real-time relative navigation cues. Autonomous operations involve automatic acquisition of the ISS, real-time tracking as well as detection and recovery from system malfunctions and/or loss of tracking. This paper presents an overview of the TriDAR system as well as results from on-orbit testing of the TriDAR during the STS-128 Space Shuttle mission.