AggieSat: Autonomous Rendezvous and Docking Technology Demonstrator

Current autonomous rendezvous and docking (AR&D) capability in low Earth orbit (LEO) is constrained by sensor and effector mass, power, and accuracy limits. To this end, NASA Johnson Space Center has developed a GPS receiver, called DRAGON (Dual RF Astrodynamic GPS Orbital Navigator), specifically to address the sensor constraints. The proposed innovation includes creating a small, low-cost, and versatile technology demonstrator to validate and increase the technology readiness level of DRAGON and other state-of-the-art miniaturized sensors and effectors in an on-orbit AR&D operational scenario. For Phase 1, a demonstration platform was developed that utilizes two picosatellites in LEO, and relative GPS as the primary sensor. These satellites were launched as a single unit from the SSPL (Space Shuttle Payload Launcher) on STS 127, to separate and transmit DRAGON data. The picosatellite technology demonstrator was at a TRL of 7 at the end of Phase 1. For Phase 2, NASA plans a second flight, and the technical objectives are to further characterize the DRAGON receiver and develop navigational solutions using DRAGON data. Additional technologies addressed include the development of a simple low-cost, low-mass three-axis stabilization and pointing system for small satellites, WiMax transceiver capabilities, and video camera capabilities. The technologies should be at a TRL of 6 at the end of Phase 2.