The Apollo program succeeded in achieving its goal of manned lunar landing, despite the major setback of a 1967 Apollo 1 cabin fire that killed the entire crew during a prelaunch test. After the first landing, sufficient flight hardware remained for nine follow-on landings with a plan for extended lunar geological and astrophysical exploration. Budget cuts forced the cancellation of three of these. Five of the remaining six missions achieved successful landings, but the Apollo 13 landing was prevented by an oxygen tank explosion in transit to the Moon, which disabled the command spacecraft's propulsion and life support. The crew returned to Earth safely by using the Lunar Module as a "lifeboat" for these functions.