Apollo
Apollo 13
Apollo 13 was intended to become humanity's third lunar landing, but an explosion in an oxygen tank transformed it into one of the greatest rescue missions in history. Through extraordinary teamwork between the crew and Mission Control, NASA safely returned all three astronauts to Earth despite catastrophic spacecraft damage.
Launch
April 11, 1970
Duration
5 days, 22 hours, 54 minutes, 41 seconds
Crew
Uncrewed
Mission record
Apollo archive entry · Successful (Landing Aborted)
Mission Overview
The mission
Apollo 13 was intended to become humanity's third lunar landing, but an explosion in an oxygen tank transformed it into one of the greatest rescue missions in history. Through extraordinary teamwork between the crew and Mission Control, NASA safely returned all three astronauts to Earth despite catastrophic spacecraft damage.
Mission Details
Program
Apollo
Launch
April 11, 1970
Duration
5 days, 22 hours, 54 minutes, 41 seconds
Status
Successful (Landing Aborted)
Mission by the Numbers
Mission Statistics
Mission Type
Crewed Lunar Mission & Emergency Return
Launch Vehicle
Saturn V AS-508
Crew
0 astronauts
Status
Successful (Landing Aborted)
Mission Goals
Mission objectives
- 01
Land astronauts in the Fra Mauro Highlands.
- 02
Conduct two lunar surface EVAs.
- 03
Deploy the Apollo Lunar Surface Experiments Package (ALSEP).
- 04
Collect geological samples from Fra Mauro.
- 05
Investigate material excavated by the Imbrium impact.
- 06
Continue Apollo lunar exploration objectives.
- 07
Safely transport astronauts to lunar orbit.
- 08
Demonstrate precision lunar landing capability.
- 09
Return lunar samples to Earth.
- 10
Safely recover the crew after splashdown.
- 11
Following the accident, preserve crew survival.
- 12
Use Aquarius as an emergency lifeboat.
- 13
Safely navigate around the Moon.
- 14
Restore Command Module functionality before reentry.
- 15
Return all three astronauts safely to Earth.
Mission Timeline
April 11, 1970 · 2:13 p.m. EST
Launch
Apollo 13 lifted off aboard Saturn V AS-508 from Kennedy Space Center, beginning NASA's third planned lunar landing mission.
Earth Orbit
Parking Orbit
Following a successful launch, Apollo 13 entered temporary Earth orbit while engineers confirmed spacecraft health before committing the crew to the Moon.
Trans-Lunar Injection
Departure for the Moon
The S-IVB third stage successfully accelerated Apollo 13 onto its translunar trajectory toward the Fra Mauro Highlands landing site.
Deep Space
Routine Flight Operations
The crew completed television broadcasts, navigation updates, spacecraft inspections, and routine systems checks during the outbound journey.
April 13, 1970 · 55:54 GET
Cryogenic Tank Stir
Mission Control instructed Jack Swigert to perform a routine stir of the spacecraft's cryogenic oxygen tanks, a standard procedure performed on previous Apollo missions.
Seconds Later
Oxygen Tank Explosion
An electrical short inside oxygen tank number two caused a catastrophic explosion that destroyed one tank, damaged the second, and ruptured part of the Service Module, placing the crew in immediate danger.
Immediately After
"Houston, We've Had a Problem"
Jack Swigert reported the emergency to Mission Control. Jim Lovell quickly confirmed that the spacecraft was losing oxygen, electrical power, and fuel cell capability.
Emergency Response
Lunar Landing Aborted
Mission Control immediately abandoned the lunar landing and shifted the mission's objective from exploration to crew survival and safe return.
Emergency Procedures
Aquarius Becomes a Lifeboat
With the Command Module rapidly losing electrical power and oxygen, the crew powered up the Lunar Module Aquarius. Designed to support two astronauts on the Moon for about 45 hours, it would now keep three astronauts alive for nearly four days.
Outbound Trajectory
Free-Return Course
Mission Control confirmed Apollo 13 could safely swing around the far side of the Moon using a free-return trajectory, allowing lunar gravity to redirect the spacecraft toward Earth.
April 14, 1970
Power Conservation
To preserve enough battery power for reentry, nearly every nonessential system aboard both spacecraft was shut down. Cabin temperatures dropped close to freezing while water consumption was drastically reduced.
Approaching the Moon
PC+2 Burn
Using Aquarius' descent engine, the crew performed the Pericynthion Plus Two burn, increasing their return speed and shortening the trip home by approximately ten hours while conserving vital consumables.
Far Side of the Moon
Closest Approach
Apollo 13 passed behind the Moon at an altitude of approximately 158 miles (254 kilometers). Although no landing would occur, the spacecraft completed its swing around the Moon and began heading home.
Return Journey
Carbon Dioxide Crisis
Carbon dioxide levels inside Aquarius began rising because its lithium hydroxide canisters were not designed to support three astronauts for several days. Engineers on Earth rapidly designed an improvised adapter using only materials available aboard the spacecraft.
Improvised Engineering
"Mailbox" CO₂ Adapter
Following instructions from Mission Control, the crew built an emergency carbon dioxide scrubber using plastic bags, cardboard, hoses, checklists, and duct tape. The improvised device successfully removed dangerous carbon dioxide from the cabin.
Return Flight
Manual Navigation
With several navigation systems unavailable, Jim Lovell used the Earth and Sun as visual references to manually align the spacecraft for critical engine burns.
Before Reentry
Command Module Power-Up
Engineers developed an entirely new low-power startup sequence for Odyssey, allowing the nearly powerless Command Module to be safely reactivated just hours before reentry.
April 17, 1970
Service Module Inspection
After separating from the damaged Service Module, the crew saw extensive external damage, including an entire side panel missing. It was the first opportunity to visually confirm the severity of the explosion.
April 17, 1970
Lunar Module Jettison
Aquarius, the spacecraft that had kept the crew alive for four days, was released shortly before Earth reentry after serving as an emergency lifeboat.
April 17, 1970
Reentry
Odyssey successfully reentered Earth's atmosphere after one of the most complex spacecraft recoveries ever attempted, surviving the expected communications blackout before parachute deployment.
April 17, 1970
Splashdown
Apollo 13 safely splashed down in the South Pacific, where USS Iwo Jima recovered the crew, bringing one of NASA's greatest rescue missions to a successful conclusion.
Mission Complete
Successful Failure
Although Apollo 13 never landed on the Moon, NASA considered the mission a successful failure because every astronaut survived despite overwhelming odds and catastrophic spacecraft damage.
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