Integrated Attitude Control Strategy for the Asteroid Redirect Mission

A deep-space mission has been proposed to redirect an asteroid to a distant retrograde orbit around the moon using a robotic vehicle, the Asteroid Redirect Vehicle (ARV). In this orbit, astronauts will rendezvous with the ARV using the Orion spacecraft. The integrated attitude control concept that Orion will use for approach and docking and for mated operations will be described. Details of the ARV's attitude control system and its associated constraints for redirecting the asteroid to the distant retrograde orbit around the moon will be provided. Once Orion is docked to the ARV, an overall description of the mated stack attitude during all phases of the mission will be presented using a coordinate system that was developed for this mission. Next, the thermal and power constraints of both the ARV and Orion will be discussed as well as how they are used to define the optimal integrated stack attitude. Lastly, the lighting and communications constraints necessary for the crew's extravehicular activity planned to retrieve samples from the asteroid will be examined. Similarly, the joint attitude control strategy that employs both the Orion and the ARV attitude control assets prior, during, and after each extravehicular activity will also be thoroughly discussed.