Apollo 13's lunar module was named Aquarius and served as a lifeboat after the spacecraft accident.
Apollo 13 launched on April 11, 1970, intending to land James Lovell and Fred Haise in the Fra Mauro region while Jack Swigert remained in lunar orbit. An oxygen-tank explosion in the service module forced the landing attempt to be abandoned.
The crew powered down the damaged command module, Odyssey, and used Aquarius for oxygen, electricity, water, and propulsion. Mission Control developed procedures that allowed the astronauts to loop around the Moon and return safely to Earth.
Aquarius was designed for lunar operations, not as an emergency spacecraft for a full crew. Its systems nevertheless supported the astronauts until shortly before re-entry, when the crew returned to Odyssey and jettisoned the lunar module.