The rapid pace of preparations for the first Moon landing continued in April 1969. The successful Apollo 9 mission in March cleared the way for Apollo 10 to test all three components of the spacecraft in lunar orbit in May, in a dress rehearsal for the landing itself. Apollo 10 astronauts Thomas P. Stafford, John W. Young, and Eugene A. Cernan and their backups L. Gordon Cooper, Donn F. Eisele, and Edgar D. Mitchell continued training in spacecraft simulators while engineers prepared their Saturn V rocket and Apollo spacecraft for the mid-May launch. Preparations continued in parallel for Apol…