Lunar and Planetary Institute

Apollo 13 Mission

Mission Overview

Mission Plan

Apollo Mission Plan

Apollo 13 was the thirteenth in a series of missions using Apollo-specification flight hardware and was to be the third lunar landing. The launch vehicle and spacecraft were similar to those of Apollo 12. There were some differences in the makeup of the ALSEP.

Mission Event List and Timeline

Launch     April 11    02:13:00 p.m. 00:00:00
Earth orbit insertion     02:25:40 p.m. 00:12:40
Translunar injection     04:54:47 p.m. 02:41:47
LO2 tank anomaly     April 13    10:07:53 p.m. 55:54:53
Trans-Earth injection     April 14    09:40:39 p.m. 79:27:39
Splashdown     April 17    01:07:41 p.m. 142:54:41


Apollo 13 LaunchThe space vehicle was launched from Kennedy Space Center, Florida, at 2:13:00 p.m. EST on April 11, 1970. During the launch, the second-stage inboard engine shut down early because of high-amplitude longitudinal oscillations; however, near-nominal trajectory parameters were achieved at orbital insertion. The Earth-orbital and translunar injection phases went as planned.


The configuration of the Apollo 13 spacecraft was nearly identical to that of Apollo 12. The structure of the command module was reinforced to accommodate higher parachute loads due to increased weight. On the lunar module, the modularized equipment storage assembly (MESA) was modified to simplify the deployment operation. Also, a heat-flow experiment and a charged particle environment detector replaced the solar wind spectrometer, magnetometer, and suprathermal ion detector experiments in the ALSEP.

The Apollo 13 spacecraft was made up of the same components as all Apollo landing missions, consisting of the two-part Command/Service Module Odyssey and the two-part Lunar Module Aquarius. As the result of the accident, however, none of these components was used in precisely the way they were originally intended.

The Service Module

The Service Module
On the Apollo spacecraft, the Service Module (SM) was intended to provide most of the consumables such as oxygen, water, and power for the mission. It was also designed to serve as the primary propulsion and maneuvering system of the spacecraft. The explosion of the oxygen tank however, led to the loss of the consumables and rendered the service module nonfunctional. The SM was retained until just before reentry to protect the command module heat shield from the possible degrading effects of long exposure to the cold of space.

The Command Module

The Command Module
Normally, the Command Module (CM), which was equipped with couches, served as the crew compartment and control center. Able to accommodate all three astronauts, the CM was also designed for reentry. Although the command module had sufficient power and consumables for a reentry, the service module provided these necessities during the rest of the mission. The command module had to be "powered down" after the accident to avoid depleting its systems and rendering it incapable of performing the reentry operation.

The Lunar Module

The Lunar Module
The Lunar Module (LM) was designed to be used only for making the landing on the Moon and providing an operating base and living quarters while on the surface. On this mission, however, it acted as a "lifeboat." With its separate systems for power and consumables, it allowed the crew to preserve the command module supplies for reentry operations. Also, as the service module could no longer provide propulsion, the LM descent engine was used to perform the maneuvers necessary to alter the spacecraft trajectory for the return to the Earth.

The Crew

James A. Lovell, Mission Commander, was born March 25, 1928, in Cleveland, Ohio. He received a bachelor of science degree from the U.S. Naval Academy (1952) and was chosen with the second group of astronauts in 1962. He was back-up pilot for Gemini 4, pilot of Gemini 7, back-up command pilot for Gemini 9, command pilot for Gemini 12, command module pilot of Apollo 8, back-up commander for Apollo 11, and commander of Apollo 13. In May 1971, he became Deputy Director of Science and Applications at the Johnson Space Center. He retired from NASA and the Navy in March 1973. James A. Lovell, Mission Commander
John L. Swigert, Jr., Command Module Pilot, was born August 30, 1931 in Denver, Colorado. He received a bachelor of science degree in mechanical engineering from the University of Colorado (1953), a master of science in aerospace science from Rensselaer Polytechnic Institute (1965), and a master of science in business administration from the University of Hartford (1967). He was chosen in the fifth group of astronauts in 1966. He was scheduled to be the back-up command module pilot for Apollo 13 but was moved to the prime crew 72 hours before the launch in place of Ken Mattingly who had been exposed to measles. Swigert took a leave of absence from NASA in April 1973 to become Executive Director of the Committee on Science and Technology, U.S. House of Representatives. He resigned from NASA and the committee in August 1977. John L. Swigert, Jr., Command Module Pilot
Fred W. Haise, Lunar Module Pilot, was born November 14, 1933, in Biloxi, Mississippi. He received a bachelor of science degree in aeronautical engineering from the University of Oklahoma (1959) and was chosen in the fifth group of astronauts in 1966. He was back-up lunar pilot for Apollo 8 and Apollo 11, lunar module pilot for Apollo 13, and backup commander for Apollo 16. He was commander of one of the crews who flew shuttle approach and landing tests and had been selected as commander of one of the shuttle orbital flight tests but resigned from NASA in June 1979. Fred W. Haise, Lunar Module Pilot,

Back-up crew for this mission were John W. Young (back-up mission commander), Ken Mattingly (back-up command module pilot), and Charles M. Duke (back-up lunar module pilot). Ken Mattingly was removed from the crew two days before launch because he had been exposed to German measles.


Apollo 13 SplashdownReentry required the unusual step of undocking the lunar module, which had been retained for the flight back to Earth, in addition to the separation of the damaged service module. The lunar module had remained attached to the spacecraft to preserve the maximum electrical power in the command module for entry. The reentry was similar to previous flights and landing occurred at 142:54:41 at 21°38'24"S latitude and 165°21'42"W longitude. The landing was within sight of the recovery ship, Iwo Jima, and the crew were on board within 45 minutes.

None of the primary misson objectives was accomplished. The mission was aborted after nearly 56 hours of flight due to the loss of service module cryogenic oxygen and consequent loss of capability to generate electricity or to provide oxygen or water. Two secondary objectives related to the impact of the S-IVB stage on the Moon, two scientific experiments not related to the ALSEP, and some photography were accomplished, however.

Mission Activities

Intended as the third lunar landing mission, Apollo 13 had a full roster of activities scheduled in addition to lunar surface activities (experiments, sampling, etc.) and photography. After the accident, virtually all activities were related to returning quickly and safely to Earth.

For more information:

Apollo 13 Mission (NSSDC)

Apollo 13 Mission (KSC)

Apollo 13 Mission (NASM)

Apollo 13 Mission (VSS)