The lander begins in a circular orbit docked to the command module. Problems with the Apollo command module continued through the testing phase. Paul Maley reports several sightings of the Apollo 12 Command Module. Command Module Pilot Richard F. Gordon Jr. flew with Conrad on Gemini 11. The central pressure vessel of the command module was its sole habitable compartment. These flights validated the service module engine and the command module heat shield. Lovell's main job as Command Module Pilot was as navigator. Mattingly was reassigned as command module pilot of Duke's flight, Apollo 16. Astronauts Grissom, White, and Chaffee, who were working inside the Command Module, were asphyxiated. The Smithsonian has been accountable for the command module "Charlie Brown" since 1970. The service module remained attached to the command module throughout the mission. The craftmaster sits in a "cockpit" or command module with a headset radio on. Worden was named as backup command module pilot (CMP) for the Apollo 12 flight. As command module pilot for Apollo 9, Scott's responsibilities were heavy. Mattingly, staying with the command module, spent 126 hours and 64 revolutions in lunar orbit.