Apollo 9

Apollo 9, was the third manned mission in the United States Apollo space program and the first flight of the Command/Service Module (CSM) with the Lunar Module (LM). Its three-person crew, consisting of Commander James McDivitt, Command Module Pilot David Scott, and Lunar Module Pilot Rusty Schweickart, tested several aspects critical to landing on the Moon, including the LM engines, backpack life support systems, navigation systems, and docking maneuvers. The mission was the second manned launch of a Saturn V rocket.

After launching on March 3, 1969, the crewmen spent ten days in low Earth orbit. They performed the first manned flight of a LM, the first docking and extraction of a LM, two spacewalks, and the second docking of two manned spacecraft—two months after the Soviets performed a spacewalk crew transfer between Soyuz 4 and Soyuz 5. The mission proved the LM worthy of manned spaceflight. Further tests on the Apollo 10 mission would prepare the LM for its ultimate goal, landing on the Moon.