NASA tests the Lunar Module

On January 22, 1968, NASA launched the Apollo 5 mission, the first - and only - unmanned test of the Lunar Module. The Saturn I rocket used for the launch was the one originally intended to launch the Apollo 1 crew into space in 1967. It was undamaged by the capsule fire and was available for this flight.

Nothing like this had ever flown before - a spacecraft with an engine that could be throttled, and which would by itself not be capable of returning its crew to the Earth.

The LM was already 8 months behind schedule in its development. To prevent further delays, NASA decided to launch the LM without its landing gear, since the legs were not crucial to the test.

A software bug prematurely shut down the descent engine on its initial test. NASA engineers executed a workaround and were able to fire the descent engine twice, and then run a "fire in the hole" test of an emergency separation of the LM's descent and ascent stages.

The test was considered successful enough that a second planned unmanned flight of the LM was deemed unnecessary. The LM for that flight now sits in the National Air and Space Museum.