Apollo program missions. Apollo 13's Fra Mauro mission was reassigned to Apollo 14, commanded in February 1971 by Mercury veteran Alan Shepard, with Stuart Roosa and Edgar Mitchell. This time the mission was successful. Shepard and Mitchell spent 33 hours and 31 minutes on the surface, and completed two EVAs totalling 9 hours 24 minutes, which was a record for the longest EVA by a lunar crew at the time. In August 1971, just after conclusion of the Apollo 15 mission, President Richard Nixon proposed canceling the two remaining lunar landing missions, Apollo 16 and 17. Office of Management and Budget Deputy
Apollo 21 in orbit. Some people have speculated that tentative plans of an "Apollo 21" might have been made assuming availability of the extra Saturn V that would have left, although by the time NASA resumed planning manned missions using this numbering sequence (defined on April 24, 1967), the dual-Saturn IB plan had been replaced with the single Saturn V. There is no evidence NASA ever planned an eleventh Moon landing mission. Apollo 21 "Apollo 21" is an apocryphal reference to an eleventh manned Moon landing mission of NASA's Apollo program. Apollo contracted for the construction of fifteen Saturn V launch vehicles