Canceled Apollo missions Schirra's crew would fly the C mission, first manned CSM (Block II CSM-101, retrofitted with the cabin safety improvements) as Apollo 7 in October 1968. McDivitt's crew and mission were kept as the first manned development LM flight (D mission); this was planned to be Apollo 8 in December 1968, now using a single Saturn V launch vehicle instead of two separate Saturn IB launches. The E mission was planned as an elliptical medium Earth orbit test of the operational LM with the CSM in a simulated lunar mission to an apogee of , to be commanded by Frank Borman
Return of Apollo 15 to Earth which was launched using a spring-loaded mechanism, a pin in a curved groove to impart a spin in the satellite. The spinning helped to stabilise the craft. After having the information needed to burn the SPS to send them home radioed from Mission Control, "Apollo 15" disappeared behind the Moon for the last time. Igniting on time, the SPS burned for 2 minutes, 21 seconds, adding 3,050 ft/s (930 m/s) to their speed. Little was left for the crew to do on their tenth day in space. They continued to photograph the lunar surface as it receded from them, using