Apollo 9 in early 1969. However, LM problems again prevented it from being ready for the D mission by December, so NASA officials created another mission for Apollo 8 using the Saturn V to launch only the CSM on the first crewed flight to orbit the Moon, and the E mission was cancelled as unnecessary. Slayton asked McDivitt and Borman which mission they preferred to fly; McDivitt wanted to fly the LM, while Borman volunteered for the pioneering lunar flight. Therefore, Slayton swapped the crews, and McDivitt's crew flew Apollo 9. The crew swap also affected who would be the first crew
Apollo 15 the same time, Command Module Pilot Alfred Worden orbited the Moon, using a scientific instrument module (SIM) in the service module (SM) to study the lunar surface and environment in great detail with a panoramic camera, a gamma-ray spectrometer, a mapping camera, a laser altimeter, a mass spectrometer, and a lunar subsatellite deployed at the end of Apollo 15's stay in lunar orbit (an Apollo program first). The mission successfully accomplished its objectives, but was marred by negative publicity that accompanied disclosure of the crew carrying unauthorized postage covers to the Moon, some of which were sold by a West