Apollo (spacecraft) Surface Experiment Packages ALSEP, the modularized equipment transporter (MET) (a hand-pulled equipment cart used on Apollo 14), the Lunar Rover (Apollo 15, 16 and 17), a surface television camera, surface tools, and lunar sample collection boxes. The ascent stage contained the crew cabin, instrument panels, overhead hatch/docking port, forward hatch, optical and electronic guidance systems, reaction control system, radar and communications antennas, ascent rocket engine and propellant to return to lunar orbit and rendezvous with the Apollo Command and Service Modules. The spacecraft–LM adapter (SLA), built by North American Aviation (Rockwell), was a conical aluminum structure which supported the service
Apollo 15 to Apollo 12, and since Apollo 11's backup crew had been designated for Apollo 13 (which did not land on the Moon), they were the first Apollo crew for a successful lunar landing mission to have backed up another such mission. Having had the opportunity to familiarize themselves with the Apollo spacecraft, they could devote more of their training time as prime crew for Apollo 15 to geology and sampling techniques. The astronauts at NASA who were scientists, such as geologist Harrison Schmitt, pushed though the early Apollo missions for a greater place for science as part of the mission,