Apollo 9 launched in March 1969, and was the countdown to Apollo 11. Flown in low Earth orbit, it was the first flight of the full Apollo spacecraft: the command and service module with the lunar module. The mission was flown to qualify the lunar module for lunar orbit operations in preparation for the first Moon landing by demonstrating its descent and ascent propulsion systems. This would also demonstrate that its crew could fly it independently, then rendezvous and dock with the command module again, as would be required for Apollo 11. The three-person crew consisted of Commander James McDivitt, command module pilot David Scott, and lunar module pilot Russell Schweickart.
In this image, McDivitt and Schweickart tested the lunar module in Earth orbit, while Scott remained behind in the command and service module. During the mission, Schweickart also performed a spacewalk to test the lunar spacesuits to be worn on the Moon.
Image Credit: NASA