The Apollo program is most famous for its greatest achievement: taking humanity to the Moon.
While the Moon landing missions garner the most fame, the others were essential to those ultimate successes.
Apollo 8 first took humans to the Moon, and Apollo 10 served as the dress rehearsal for the first landing.
But in between was Apollo 9, which was needed to prove the capabilities of the complete Apollo spacecraft.
Successfully landing on the Moon and returning astronauts to Earth would require novel technology: the Lunar Module.
The crew of James McDivitt, David Scott, and Rusty Schweickart rocketed into space aboard a Saturn V on March 3, 1969.
From low Earth orbit, they performed the first crewed flight of Apollo’s Lunar Module.
They successfully demonstrated module docking and extraction, proving Apollo was capable of a successful landing and return.
They completed a two-person spacewalk and successfully tested engines, spacesuit life support, and navigation.
This marked the first test of the complete Apollo assembly in space.
It proved that Apollo was capable of a complete, successful round-trip involving landing on the Moon.
Apollo 9’s crew joins the Apollo 8 astronauts as the only ones whose members all remain alive today.