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Apollo 13
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Apollo 13

Failed 1970 lunar mission whose free-return arc Artemis II replicates.

Apollo 13's 1970 free-return survival regained relevance on 6 April when Artemis II passed its human-distance record on a planned lunar arc.

Last refreshed: 22 September 2026

Key Question

How does Apollo 13's survival shape Artemis II's flight plan?

Timeline for Apollo 13

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Background

Apollo 13 was a crewed Apollo lunar mission whose planned landing was aborted after an oxygen-tank explosion in 1970. Its CREW returned safely by following a free-return trajectory, in which lunar gravity carries a spacecraft around the Moon and back towards Earth.

The mission remains a defining example of contingency planning in human spaceflight. A free-return route does not remove every danger, but it preserves a return PATH without requiring a lunar landing or a separate turn-home manoeuvre.

Apollo 13 also held the human distance record from Earth at 248,655 miles until Artemis II's planned passage beyond it on 6 April 2026. Its lasting significance lies in the link between a failed mission objective and a successful CREW recovery.

Key Issues
Lunar safety

Apollo 13 remains a safety reference

On 2 April, Artemis II controllers prepared to commit four astronauts to a lunar free-return trajectory, the type of route that brought Apollo 13's crew home after its 1970 emergency. For Apollo 13, the arc turned an aborted landing into a survivable return.

On 6 April, Artemis II was due to exceed Apollo 13's 248,655-mile distance record by 3,366 miles. The comparison keeps Apollo 13 relevant as more than a historic mishap: its route remains the clearest public example of why a lunar mission can retain a PATH home after a major systems failure.

Common Questions
What is the free-return trajectory Apollo 13 used?
A free-return trajectory is a flight PATH that uses lunar gravity to sling the spacecraft back to Earth without any engine burn, providing a passive abort option.Source: NASA Apollo 13 mission report
How far did Apollo 13 travel from Earth?
The CREW reached 248,655 miles (400,171 km) — the current human distance record from Earth.Source: NASA Apollo 13 mission records
Will Artemis II break Apollo 13's distance record?
Yes. Artemis II is expected to surpass 248,655 miles once Orion completes its lunar flyby.Source: NASA Artemis II mission profile
What went wrong on Apollo 13?
An oxygen tank exploded on day two, disabling the Command Module. The CREW used the Lunar Module as a lifeboat and returned safely on a free-return arc.Source: NASA Apollo 13 mission report
Why does Artemis II use the same route as Apollo 13?
The free-return trajectory is a proven safety mechanism. Apollo 13 demonstrated it could bring a crippled spacecraft home without engine power.Source: NASA Artemis II mission overview