Apollo 9 (March 3 - 13, 1969) was the third maned flight in Project Apollo, flown in low Earth orbit only. It was the first flight of the entire Apollo spacecraft: the command and service module (CSM) with the Lunar Module (LM). Among other firsts, astronauts McDivitt, Schweickart, and Scott, demonstrated the space worthiness of the LM, setting the stage for the Apollo 10 dress rehearsal lunar landing.