Apollo 13

This article is about the 1970 Apollo mission. For the film based upon it, see Apollo 13 (film). For other uses, see Apollo 13 (disambiguation).

Apollo 13

Apollo 13's damaged service module, seen from the command module, as it was being jettisoned shortly before reentry
Mission type	Crewed lunar landing attempt
Operator	NASA
COSPAR ID	1970-029A
SATCAT no.	4371
Mission duration	5 days, 22 hours, 54 minutes, 41 seconds
Spacecraft properties
Spacecraft	Apollo CSM-109 Apollo LM-7
Manufacturer	CSM: North American Rockwell LM: Grumman
Launch mass	101,261 pounds (45,931 kg)
Landing mass	11,133 pounds (5,050 kg)
Crew
Crew size	3
Members	James A. Lovell, Jr. John L. Swigert, Jr. Fred W. Haise, Jr.
Callsign	CM: Odyssey LM: Aquarius
Start of mission
Launch date	April 11, 1970, 19:13:00 (1970-04-11UTC19:13Z) UTC
Rocket	Saturn V SA-508
Launch site	Kennedy LC-39A
End of mission
Recovered by	USS Iwo Jima
Landing date	April 17, 1970, 18:07:41 (1970-04-17UTC18:07:42Z) UTC
Landing site	South Pacific Ocean 21°38′24″S 165°21′42″W
Flyby of Moon (orbit and landing aborted)
Closest approach	April 15, 1970, 00:21:00 UTC
Distance	254 kilometers (137 nmi)
Docking with LM
Docking date	April 11, 1970, 22:32:08 UTC
Undocking date	April 17, 1970, 16:43:00 UTC
Lovell, Swigert, Haise, 12 days after their return. Apollo program

Apollo 13 was the seventh crewed mission in the Apollo space program and the third intended to land on the Moon. The craft was launched from Kennedy Space Center (KSC) on April 11, 1970, but the lunar landing was aborted after an oxygen tank in the service module (SM) failed two days into the mission. The crew instead looped around the Moon, and returned safely to Earth on April 17, 1970. The mission was commanded by Jim Lovell with Jack Swigert as command module pilot (CMP) and Fred Haise as lunar module pilot (LMP). Swigert was a late replacement for the original CMP Ken Mattingly, who was grounded after exposure to rubella.

The oxygen tank failure was caused by accidental ignition of damaged wire insulation inside it during a routine tank stirring operation. The SM soon lost all its oxygen, needed for breathing and for generating electrical power. Command module (CM) power had to be shut down to conserve its remaining resources for reentry, forcing the crew to transfer to the lunar module (LM) as a lifeboat. With the lunar landing cancelled, mission controllers worked feverishly to bring the crew home alive.

Although the LM was designed to support two men on the lunar surface for two days, Mission Control in Houston improvised new procedures so it could support three men for four days. The crew experienced great hardship caused by limited power, a chilly and wet cabin and a shortage of potable water. There was a critical need to adapt the CM's cartridges for the carbon dioxide removal system to work in the LM; the crew and mission controllers were successful in improvising a solution. The astronauts' peril sparked renewed interest in the Apollo program, with tens of millions watching the splashdown in the South Pacific Ocean by television.

An investigative review board found fault with the testing of the oxygen tank and the fact combustible Teflon was placed inside it; a number of changes were made for Apollo 14. The flight passed the far side of the Moon at an altitude of 254 kilometers (137 nautical miles) above the lunar surface, and 400,171 km (248,655 mi) from Earth, a spaceflight record marking the farthest humans have traveled from Earth. The story of Apollo 13 has been dramatized multiple times, most notably in the 1995 film Apollo 13.

Astronauts and key Mission Control personnel

Swigert, Lovell and Haise two days before launch

The mission commander, Jim Lovell, was 42 years old at the time of the mission, which was his fourth and last. He was a graduate of the United States Naval Academy and had been a naval aviator and test pilot before being selected for the second group of astronauts in 1962; he flew with Frank Borman in Gemini 7 and Buzz Aldrin in Gemini 12 before flying in Apollo 8 in 1968, the first spacecraft to orbit the Moon.

Jack Swigert, the command module pilot, was 38 years old and held a B.S. in mechanical engineering and an M.S. in aerospace science; he had served in the Air Force and in state air national guards, and was an engineering test pilot prior to being selected for the fifth group of astronauts in 1966. Fred Haise, the lunar module pilot was 35 years old. He held a B.S. in aeronautical engineering, had been a Marine Corps fighter pilot, and was a civilian research pilot for NASA when he was selected as a Group 5 astronaut. Apollo 13 was Swigert's and Haise's only spaceflight.

According to the standard Apollo crew rotation, the prime crew for Apollo 13 would have been the backup crew for Apollo 10 with Mercury and Gemini veteran Gordon Cooper in command, Donn F. Eisele as command module pilot (CMP) and Edgar Mitchell as lunar module pilot (LMP). Deke Slayton, NASA's Director of Flight Crew Operations, never intended to rotate Cooper and Eisele to a prime crew assignment, as both were out of favor – Cooper for his lax attitude towards training, and Eisele for incidents aboard Apollo 7 and an extra-marital affair. He assigned them to the backup crew because no other veteran astronauts were available.

Slayton's original choices for Apollo 13 were Alan Shepard for commander, Stuart Roosa for command module pilot, and Mitchell as lunar module pilot. However, management felt Shepard needed more training time, as he had only recently resumed active status after surgery for an inner ear disorder which had kept him grounded since 1961. Thus Lovell's crew (himself, Haise and Ken Mattingly) having all backed up Apollo 11 and been slated for Apollo 14) was swapped with Shepard's.

NASA assigned a backup crew of John Young as commander, Jack Swigert as command module pilot and Charles Duke as lunar module pilot. Seven days before launch, Duke contracted rubella from one of his children. This exposed both the prime and backup crews, who trained together, and Mattingly (alone of the five) was not immune through prior exposure. Normally, if any member of the prime crew had to be replaced the remaining crew would be replaced as well, and the backup crew substituted, but Duke's illness ruled this out so Swigert was simply substituted for Mattingly.

The flight directors in Mission Control during Apollo had a one-sentence job description, "The flight director may take any actions necessary for crew safety and mission success." For Apollo 13, they were: Gene Kranz, White team, (the lead flight director); Glynn Lunney, Black team; Milt Windler, Maroon team and Gerry Griffin, Gold team.

Launch vehicle and spacecraft

The Apollo 13 launch vehicle is rolled out, December 1969

The Saturn V used to carry Apollo 13 to the Moon was numbered SA-508, and was almost identical to those used on Apollo 8 through 12. Including the spacecraft, the rocket was 25,600 pounds (11,600 kg) heavier than Apollo 12's. The S1-C engines were rated at 100,000 pounds (45,000 kg) less total thrust than Apollo 12's, though they remained within specifications. Extra fuel was carried; the reason for this was in part as a preliminary to the future J missions to the Moon that would carry heavier payloads. This made the vehicle the heaviest yet flown by NASA and made Apollo 13 visibly slower to clear the launch tower than earlier missions.

CSM-109 Odyssey being assembled and tested

The Apollo 13 spacecraft consisted of Command Module 109 and Service Module 109 (together CSM-109), called Odyssey, and Lunar Module 7 (LM-7), called Aquarius. Also considered part of the spacecraft were the launch escape system which would propel the CM to safety in the event of a problem during launch, and the Spacecraft–LM Adapter, numbered as SLA-16, which housed the LM during the first hours of the mission.

Apollo 13's designated landing site was near Fra Mauro crater; the Fra Mauro formation was believed to contain much material spattered by the impact that had filled the Imbrium basin early in the Moon's history. Dating it would provide information not only about the Moon, but about the Earth's early history. The landing site was near what was dubbed Cone crater, a site where an impact was believed to have drilled deep into the lunar regolith. Due to the roughness of the terrain, the selected landing site was over a mile (two kilometers) from Cone crater, but Lovell, who as commander was to perform the landing, had the option of setting down closer if he believed he could do so safely. NASA initially had few high-quality photographs of that location, but after Apollo 12 took more from orbit in November 1969, Fra Mauro was confirmed as Apollo 13's landing site.

Concerned about how close Apollo 11's LM, Eagle, had come to running out of propellant during its lunar descent, mission planners decided that beginning with Apollo 13, the CSM would bring the LM to the low orbit from which the landing attempt would commence. This was a change from Apollo 11 and 12, on which the LM made the burn to bring it to the lower orbit. The change was part of an effort to increase the amount of hover time available to the astronauts as the missions headed into rougher terrain.

The LM stages, CM and SM were received at KSC in June 1969; the portions of the Saturn V were received in June and July. Thereafter, testing and assembly proceeded, culminating with the rollout of the launch vehicle, with the spacecraft atop it, on December 15, 1969. Apollo 13 was originally scheduled for launch on March 12, 1970; in January of that year NASA announced the mission would be postponed until April 11, both to allow additional time for planning and to spread the Apollo missions over a longer period of time.

Training and preparation

Lovell practices deploying the flag

The astronauts of Apollo 11 had minimal time for geology training, with only six months between crew assignment and launch; higher priorities took much of their time. Apollo 12 saw more training, including practice traverses, using a CAPCOM and a simulated backroom of scientists, to whom the astronauts had to describe what they saw. Scientist-astronaut Harrison Schmitt saw that there was limited enthusiasm for geology field trips. Believing an inspirational teacher was needed, Schmitt arranged for Lovell and Haise to meet his old professor, Caltech's Lee Silver. The two astronauts, and backups Young and Duke, went on a field trip with Silver at their own time and expense. At the end of their week together, Lovell made Silver their geology mentor, who would be extensively involved in the geology planning for Apollo 13. Farouk El-Baz oversaw the training of Mattingly and his backup, Swigert, which involved describing and photographing simulated lunar landmarks from airplanes. El-Baz had all three prime crew astronauts describe geologic features they saw during their flights between Houston and Kennedy Space Center (KSC); Mattingly's enthusiasm caused other astronauts, such as Apollo 14's CMP, Stu Roosa, to seek out El-Baz as a teacher.

Lovell (left) and Haise during geology training in Hawaii, January 1970

A month before the planned landing, Lovell and Haise undertook a mock EVA at Arizona's Verde Valley, over a landscape made to look as much like the lunar surface as possible. The Apollo 13 prime crew undertook over 1,000 hours of mission-specific training, more than five hours for every hour of the mission's ten-day planned duration. Each member of the prime crew spent over 400 hours in simulators of the CM and of the LM at KSC and at Houston, some of which involved the flight controllers at Mission Control. Specialized simulators at other locations were also used.

The plan was to devote the first of the two four-hour lunar surface EVAs to setting up scientific instruments; during the second, Aquarius's crew would investigate Cone crater, near the planned landing site. Lovell and Haise wore their spacesuits for some 20 walk-throughs of EVA procedures, including sample gathering and use of tools and other equipment. The astronauts flew in the "Vomit Comet" in simulated microgravity or lunar gravity, including practice in donning and doffing spacesuits. To prepare for the descent to the Moon's surface, Lovell flew the Lunar Landing Training Vehicle (LLTV). Despite the fact that four of the five LLTVs and similar Lunar Landing Research Vehicles crashed during the course of the Apollo program, mission commanders considered flying them invaluable experience.

Experiments and scientific objectives

Lovell practices deploying the ALSEP during training

Apollo 11 had left a seismometer on the Moon, but the solar-powered unit did not survive its first two-week-long lunar night. The Apollo 12 astronauts also left one as part of its package of nuclear-powered scientific instruments. Apollo 13 carried a seismometer (known as the Passive Seismic Experiment, or PSE) similar to Apollo 12's as part of its ALSEP package of scientific instruments, which was carried in the LM descent stage's scientific equipment bay. That seismometer was to be calibrated by the impact, after jettison, of the ascent stage of Apollo 13's LM, an object of known mass and velocity impacting at a known location.

Other ALSEP experiments included a Heat Flow Experiment (HFE), which would involve the drilling of two holes 10 feet (3.0 m) deep. This was Haise's responsibility; he was also to drill a third hole of that depth for a core sample. A Charged Particle Lunar Environment Experiment (CPLEE) measured the protons and electrons of solar origin reaching the Moon. The package also included a Lunar Atmosphere Detector (LAD) and a Dust Detector, to measure the accumulation of debris. The Heat Flow Experiment and the CPLEE were flown for the first time on Apollo 13; the other experiments had been flown before.

Haise practices removing the fuel capsule from its transport cask mounted on the LM. The real cask sank unopened into the Pacific Ocean with its radioactive contents.

To power the ALSEP, the SNAP-27 radioisotope thermoelectric generator was flown. Developed by the U.S. Atomic Energy Commission, SNAP-27 was first flown on Apollo 12. The fuel capsule contained about 8.36 pounds (3.79 kg) of plutonium oxide. The cask placed around the capsule for transport to the Moon was built with heat shields of graphite and of beryllium, and with structural parts of titanium and of Inconel materials. Thus, it was built to withstand the heat of reentry into the Earth's atmosphere in the event of an aborted mission.

Like Apollo 11 and 12, Apollo 13 flew the Solar Wind Composition Experiment, a windowshade-like device that would be deployed on the lunar surface and then be folded up and brought back by the astronauts. It also flew the Lunar Stereo Closeup Camera, intended to show the fine structure of lunar rocks and soil. A United States flag was also taken, to be erected on the Moon's surface. For Apollo 11 and 12, the flag had been placed in a heat-resistant tube on the front landing leg; it was moved for Apollo 13 to the Modularized Equipment Stowage Assembly (MESA) in the LM descent stage. The structure to fly the flag on the airless Moon was improved from Apollo 12's.

For the first time, red stripes were placed on the helmet, arms and legs of the commander's A7L spacesuit. This was done as after Apollo 11, those reviewing the images taken had trouble distinguishing Armstrong from Aldrin, but the change was approved too late for Apollo 12. The Apollo 12 moon walkers had gotten thirsty during their lunar surface activities; the new drink bags that could be placed inside the helmets and sipped from as the astronauts explored were demonstrated by Haise during Apollo 13's final television broadcast before the accident.

The crater created by the S-IVB's impact, as photographed by the Lunar Reconnaissance Orbiter, 2010

Apollo 13's primary mission objectives were to: "Perform selenological inspection, survey, and sampling of materials in a preselected region of the Fra Mauro Formation. Deploy and activate an Apollo Lunar Surface Experiments Package. Develop man's capability to work in the lunar environment. Obtain photographs of candidate exploration sites." The astronauts were also to accomplish other photographic objectives, including of the Gegenschein from lunar orbit, and of the Moon itself on the journey back to Earth. Some of this photography was to be performed by Swigert as Lovell and Haise walked on the Moon. The command module pilot was also to take photographs of the Lagrangian points of the Earth-Moon system. Apollo 13 had twelve cameras on board, including those for television and moving pictures. The crew was also to downlink bistatic radar observations of the Moon. None of these was attempted because of the accident.

Several experiments were completed nonetheless. An experiment to measure the amount of atmospheric electrical phenomena during the ascent to orbit – added after Apollo 12 was struck by lightning – returned data indicating a heightened risk during marginal weather. A series of photographs of Earth, taken to test whether cloud height could be determined from synchronous satellites, achieved the desired results. An experiment to use Apollo 12's seismometer to detect the impact of Apollo 13's S-IVB (the third stage of the Saturn V) onto the Moon went as planned. On previous missions, the S-IVB was sent into solar orbit once detached. The seismometer left by Apollo 12 had detected frequent impacts of objects onto the Moon, but larger impacts would yield more information about the Moon's crust so it was decided that beginning with Apollo 13, the S-IVB stage would be crashed into the Moon. The impact occurred at 77:56:40 and produced enough energy that the gain on the seismometer, 73 miles (117 km) from the impact, had to be reduced.

Spaceflight

The circumlunar trajectory followed by Apollo 13, drawn to scale; the accident occurred about 56 hours into the mission

Apollo 13 spacecraft configuration en route to the Moon

Launch and translunar injection

Apollo 13 launches from Kennedy Space Center, April 11, 1970

The mission was launched at the planned time, 02:13:00 PM EST (19:13:00 UTC) on April 11. Swigert performed the separation and transposition maneuvers before docking the CSM Odyssey to the LM Aquarius, and the spacecraft pulled away from the third stage, which ground controllers then sent on a course to impact the Moon within range of the seismometer left there by Apollo 12.

At 30:40:50 (that is, 30 hours 40 minutes 50 seconds from launch) a burn redirected Apollo 13 from its free return trajectory onto a hybrid trajectory; this meant a quicker flight to Fra Mauro and more propellant available for the lunar descent, but also that without a further burn at a later time, the spacecraft would miss Earth on its return (rather than intercept it as with a free return). There was a moment of amusement when Swigert realized that he would miss the April 15 deadline for filing his income tax return; it was found that being outside the US at the deadline qualified him for an extension.

Accident

For the cause of the accident, see [[:Apollo 13 investigation]].

Mission Operations Control Room during the TV broadcast just before the accident. LMP Haise is seen on the screen; Gene Kranz is seated in the foreground.

On the third day the crew entered the LM to test its systems, and at 55:00:00 Lovell gave a televised tour of both Odyssey and Aquarius though none of the television networks carried the broadcast. Approximately six and a half minutes after the TV broadcast – approaching 56:00:00 – Apollo 13 was about 180,000 nautical miles (210,000 mi; 330,000 km) from Earth. Haise was completing the shutdown of the LM after testing its systems while Lovell stowed the TV camera. Jack Lousma, the CAPCOM, sent a number of minor instructions to Swigert, including changing the attitude of the craft to facilitate photography of Comet Bennett.

The pressure sensor in one of the SM's oxygen tanks had earlier appeared to be malfunctioning, so Sy Liebergot (the EECOM, in charge of monitoring the CSM's electrical system) requested that the stirring fans in the tanks be activated. Normally this was done once daily; this additional stir would destratify the contents of the tanks, making the pressure readings more accurate. The Flight Director, Gene Kranz, had Liebergot wait a few minutes for the crew to settle down after the telecast, then Lousma relayed the request to Swigert, who activated the switches controlling the fans, then after a few seconds turned them off again.

At 55:54:53 – ninety-five seconds after Swigert turned on the fans – the astronauts heard a "pretty large bang", and Haise heard the attitude control thrusters fire as he passed through the docking tunnel. Contact with Earth was lost for 1.8 seconds, until the high-gain S-band antenna automatically switched from narrow-beam mode to wide-beam.

After another 26 seconds Swigert reported, "Okay, Houston, we've had a problem here." Lovell initially thought that Haise had activated the LM's cabin-repressurization valve, which Haise enjoyed doing because it produced a startling bang, but Lovell could see that Haise was puzzled, and at 55:55:42 he echoed Swigert: "Houston, we've had a problem. We've had a Main B Bus undervolt." Swigert initially thought that a meteoroid might have struck, but it was quickly realized that cabin atmosphere was not leaking away.

Low voltage on the B Bus (one of the SM's two electrical distribution systems) suggested a malfunction in the fuel cells fueled by hydrogen and oxygen piped from the tanks; soon the A Bus was showing low voltage as well. Checking the status of the three fuel cells, Haise found that two were dead.

Liebergot initially missed the worrying signs from tank 2 during the stir, as he was focusing on tank 1, believing that its reading would be a good guide to what was present in tank 2; so did controllers supporting him in the "back room". In the minutes after the accident, there were a number of unusual readings, showing that tank 2 was empty and tank 1's pressure slowly falling, that the computer on the spacecraft had reset, and that the high-gain antenna was not working. When Kranz questioned Liebergot on this he initially responded that there might be an instrumentation problem; he was often teased about that in the years to come. but Lovell, looking out the window, reported "a gas of some sort" venting into space, making it clear that there was a serious problem.

Since the fuel cells needed oxygen to operate, when Oxygen Tank 1 ran dry, the remaining fuel cell would shut down, meaning the CSM's only significant power and oxygen would be the CM's batteries and its oxygen "surge tank". These would be needed for the final hours of the mission, but the remaining fuel cell, already starved for oxygen, was drawing from the surge tank. Kranz ordered the surge tank isolated, saving its oxygen, but this meant that the remaining fuel cell would die within two hours, as the oxygen in Tank 1 was consumed or leaked away. A lunar landing was ruled out without all three fuel cells functioning so the mission's goal became simply getting the astronauts back to Earth alive.

Looping around the Moon

This depiction of a direct abort (from a 1966 planning report) contemplates returning from a point much earlier in the mission, and closer to Earth, than where the Apollo 13 accident occurred.

The lunar module had charged batteries and full oxygen tanks for use on the lunar surface, so Kranz directed that the astronauts power up the LM and use it as a "lifeboat" – a scenario anticipated but considered unlikely. (Had the accident occurred on the return voyage, with the LM unavailable, it would have been impossible for the crew to survive.)

A key decision was the choice of return path. A "direct abort" would use the SM's main engine (the "service propulsion system" or SPS) to turn around before reaching the Moon. But the accident could have damaged the SPS, and the fuel cells would have to last at least another hour to meet its power requirements, so Kranz instead decided on a longer route: the spacecraft would swing around the Moon before heading back to Earth. But Apollo 13 was on the hybrid trajectory which was to take it quickly to Fra Mauro, so it now needed to be brought back to a free return. The LM's Descent Propulsion System (DPS), although not as powerful as the SPS, could do this, but new software needed be written by technicians as it had never been contemplated that the CSM/LM spacecraft would have to be maneuvered by the DPS. As the CM was being shut down, Lovell copied down its guidance system's orientation information and made manual calculations to transfer it to the LM's guidance system, which had been turned off; at his request Mission Control checked the math. At 61:29:43.49 the DPS burn of 34.23 seconds took Apollo 13 back to a free return trajectory.

The Apollo 13 crew photographed the Moon out of the Lunar Module.

The change would get Apollo 13 back to Earth in about four days' time, with splashdown in the Indian Ocean, a place where NASA had few recovery forces. Jerry Bostick and other Flight Dynamics Officers (FIDOs) were anxious both to shorten the time, and to get Apollo 13 down in the Pacific Ocean, where the main recovery forces were located. There was a relatively quick option that would shave 36 hours off the return time, but it would involve jettisoning the SM, which would expose the CM's heat shield to space for the return journey, something it had not been designed to endure. The FIDOs also proposed other solutions. After a meeting involving a number of NASA officials and engineers, the senior individual present, Manned Spaceflight Center director Robert R. Gilruth decided on a burn that would save 12 hours and land Apollo 13 in the Pacific. This burn would take place with the DPS two hours after the point of closest approach to the Moon, or pericynthion, and was given the shorthand of PC+2 burn. Kranz's White Team of mission controllers spent most of their time in support of other teams and developing procedures, but took their consoles for the crucial PC+2 burn. As the crew prepared for the burn, they were informed that the S-IVB had impacted the Moon as planned, leading Lovell to quip, "Well, at least something worked on this flight."

Normally, the accuracy of such a burn could be assured by checking the alignment Lovell had transferred to the LM's computer against the position of one of the stars astronauts used for navigation, but the light glinting off the many pieces of debris accompanying the spacecraft made that impractical. The astronauts used the one star available whose position could not be obscured–the Sun. Houston also informed them that the Moon would be centered in the commander's window of the LM as they made the burn, which was almost perfect – less than a foot (.3 meters) per second off. The burn took place at 79:27:38.95 and lasted four minutes, 23 seconds. With Apollo 13 headed towards a splashdown in the Pacific, the crew turned its attention to shutting down most LM systems to conserve consumables.

Return to earth

Swigert, at right, with the "mailbox" rig improvised to adapt the CM's square lithium hydroxide canisters to fit the LM, which took a round cartridge

Aquarius was designed to accommodate two astronauts during a lunar surface mission of at most 45 hours; now it would have to sustain three people for 77 to 100 hours, depending on the trajectory taken. The LM carried sufficient oxygen, but unlike the command and service module (CSM), which was powered by fuel cells that produced water as a byproduct, the LM was powered by silver-zinc batteries, so conservation of electrical power and water (used for equipment cooling as well as drinking) would be imperative. Accordingly, LM power consumption was reduced to the lowest levels possible; Swigert was able to fill some drinking bags with water from the CM's water tap, but even assuming rationing of personal consumption Haise initially calculated they would run out of water for cooling about five hours before reentry. This did not present a major hazard because Haise knew that Apollo 11's LM, Eagle, once jettisoned in lunar orbit, had its systems continue to operate for 7–8 hours even with the water cut off. In the end, Apollo 13 returned to Earth with 28.2 pounds (12.8 kg) of water remaining. Their daily ration of .2 liters of water each may have been inadequate, given that the three astronauts lost a total of 31 pounds (14 kg) among them and Haise fell ill with an infection.

Lovell tries to rest in the frigid spacecraft

Availability of lithium hydroxide (LiOH) for removing carbon dioxide presented a serious problem. The LM's internal stock of LiOH canisters was not sufficient to support the crew until return, and the remainder was stored in the descent stage, out of reach. The CM had an adequate supply of canisters, but these were incompatible with the LM. Engineers on the ground improvised a way to join the cube-shaped CM canisters to the LM's cylindrical canister-sockets by drawing air through them with a suit return hose. NASA engineers referred to the improvised device as "the mailbox." The procedure to build the device was read up to the crew by CAPCOM Joe Kerwin over the course of an hour, and it was built by Swigert and Haise. Once built and installed, the device allowed the CM's canisters to work, leading to a sharp drop in the carbon dioxide level. Lovell later described the solution to the carbon dioxide problem as "a great improvisation—and a fine example of cooperation between ground and space".

Apollo 13: Houston, We've Got a Problem (1970) — Documentary about the mission by NASA (28:21)

Inside the darkened spacecraft, the temperature dropped to as low as 38 °F (3 °C). Lovell considered having the crew don their spacesuits, but decided this would be too hot. Instead, Lovell and Haise wore their lunar EVA boots and Swigert put on an extra coverall. All three astronauts were cold, especially Swigert who got his feet wet and had no lunar overshoes to insulate them. As they had been asked not to make any waste dumps, they had to find ways to store their urine in bags. Water condensed on the walls of the spacecraft, and, the crew feared, under the panels where there was electrical wiring. This turned out not to be a problem, partly because of the extensive electrical insulation improvements instituted after the Apollo 1 fire. Despite the difficult conditions, the crew voiced few complaints.

Another problem, solved by flight controller John Aaron along with Mattingly and various engineers and designers, was devising a procedure for powering up the command module from full shutdown – something never intended to be done in flight, much less under Apollo 13's severe power and time constraints.

Reentry and splashdown

President Richard Nixon, National Security Advisor Henry Kissinger and former astronauts Michael Collins and William Anders watch the splashdown of Apollo 13 on television

Despite the accuracy of the transearth injection, the spacecraft slowly drifted off course, necessitating a midcourse correction. As the LM's guidance system had been shut down following the PC+2 burn, the crew was called upon to use the terminator line between night and day on the Earth to guide them, a technique used on NASA's earth-orbit missions but never on the way back from the Moon. This burn was done using the DPS at 105:18:42 for 14 seconds, bringing the projected entry flight path angle back within safe limits. Nevertheless, an additional burn needed to be made, using the LM's reaction control system (RCS) thrusters, for 21.5 seconds at 137:40:13. The SM was jettisoned less than half an hour later, allowing the crew to see the damage for the first time, and photograph it. They reported that an entire panel was missing from the SM's exterior, the fuel cells above the oxygen tank shelf were tilted, that the high-gain antenna was damaged, and there was a considerable amount of debris elsewhere. Haise could see damage to the SM's engine bell, validating Kranz's decision not to use the SPS.

Apollo 13 splashes down in the South Pacific on April 17, 1970

The last problem to be solved was how to separate the lunar module a safe distance away from the command module just before reentry. The normal procedure was to use the service module's RCS to pull the CSM away after releasing the LM along with the command module's docking ring, but the SM would be released before the LM, and was in any event inoperative. Grumman, the manufacturer of the LM, called a team of six University of Toronto engineers, led by senior scientist Bernard Etkin, to solve the problem within a day. The team concluded that pressurizing the tunnel connecting the lunar module to the command module just before separation would provide the force necessary to push the two modules a safe distance away from each other just prior to reentry. The team had six hours to accurately compute the pressure required, using slide rules. Too high a pressure could damage the hatch and its seal, endangering the astronauts on reentry; too low and the lunar module would not be sufficiently separated. Grumman relayed their calculation to NASA, and from there in turn to the astronauts, who used it successfully.

Ionization of the air around the command module during reentry would typically cause a four-minute communications blackout. Apollo 13's shallow reentry path lengthened this to six minutes, longer than had been predicted; there was great tension and fear that the CM's heat shield had failed. Odyssey regained radio contact and splashed down safely in the South Pacific Ocean, 21°38′24″S 165°21′42″W, southeast of American Samoa and 6.5 km (3.5 nmi) from the recovery ship, USS Iwo Jima. Although fatigued, the crew was in good condition except for Haise, who was suffering from a serious urinary tract infection because of insufficient water intake. The crew stayed overnight on the ship and flew to Pago Pago, Samoa, the next day. They flew to Hawaii, where President Nixon awarded them the Presidential Medal of Freedom, the highest civilian honor. They stayed overnight, and then were flown back to Houston.

On his way to Honolulu, President Nixon flew to Houston to award the Apollo 13 Mission Operations Team the Presidential Medal of Freedom. He originally planned to give NASA administrator Dr. Thomas O. Paine the award, but Paine recommended the mission operations team.

Public and media reaction

Nobody believes me, but during this six-day odyssey we had no idea what an impression Apollo 13 made on the people of Earth. We never dreamed a billion people were following us on television and radio, and reading about us in banner headlines of every newspaper published. We still missed the point on board the carrier Iwo Jima, which picked us up, because the sailors had been as remote from the media as we were. Only when we reached Honolulu did we comprehend our impact: there we found President Nixon and [NASA Administrator] Dr. Paine to meet us, along with my wife Marilyn, Fred's wife Mary (who being pregnant, also had a doctor along just in case), and bachelor Jack's parents, in lieu of his usual airline stewardesses.

— Jim Lovell

Worldwide interest in the Apollo program was reawakened by the incident; television coverage of which was seen by millions. Four Soviet ships headed toward the landing area to assist if needed, and other nations offered assistance should the craft have to splash down elsewhere. President Richard Nixon cancelled his appointments, phoned the astronauts' families, and drove to NASA's Goddard Space Flight Center in Greenbelt, Maryland, where Apollo's tracking and communications were coordinated.

The rescue received more public attention than most spaceflights to that point, other than the first Moon landing on Apollo 11. There were worldwide headlines, and people surrounded television sets to get the latest developments, offered by networks who interrupted their regular programming for bulletins. Pope Paul VI led a congregation of 10,000 people in praying for the astronauts' safe return; ten times that number also offered prayers at a religious festival in India. The United States Senate on April 14 passed a resolution urging businesses to pause at 9 pm local time that evening to allow for employee prayer.

An estimated 40 million Americans watched Apollo 13's splashdown, carried live on all three networks, with another 30 million watching some portion of the six and one-half hour telecast. Even more outside the U.S. watched. Jack Gould of The New York Times stated that Apollo 13, "which came so close to tragic disaster, in all probability united the world in mutual concern more fully than another successful landing on the moon would have".

Investigation and response

Review board

Oxygen tank number 2, showing heater and thermostat unit

Immediately upon the crew's return, NASA Administrator Paine and Deputy Administrator George Low appointed a review board – chaired by NASA Langley Research Center Director Edgar M. Cortright and including Neil Armstrong and six others – to investigate the accident. The board's final report, sent to Paine on June 15, found that the failure began in the service module's number 2 oxygen tank. Damaged Teflon insulation on the wires to the stirring fan inside Oxygen Tank 2 allowed the wires to short-circuit and ignite this insulation. The resulting fire rapidly increased pressure inside the tank and the tank dome failed, filling the fuel cell bay (SM Sector 4) with rapidly expanding gaseous oxygen and combustion products. The escaping gas was probably enough by itself to blow out the aluminum exterior panel to Sector 4, but there may also have been combustion products generated as nearby insulation may have briefly burned until the departure of the panel exposed the sector to space, snuffing out the fire. As it went, the panel probably hit the nearby high-gain antenna, disrupting communications to Earth for 1.8 seconds. The report questioned the use of Teflon and other materials shown to be flammable in supercritical oxygen, such as aluminum, within the tank. The board found no evidence pointing to any other theory of the accident.

Mechanical shock forced the oxygen valves closed on the number 1 and number 3 fuel cells, putting them out of commission. The sudden failure of Oxygen Tank 2 compromised Oxygen Tank 1, causing its contents to leak out, possibly through a damaged line or valve, over the next 130 minutes, entirely depleting the SM's oxygen supply. With both SM oxygen tanks emptying, and with other damage to the SM, the mission had to be aborted.

Oxygen Tank 2 was manufactured by the Beech Aircraft Company of Boulder, Colorado, as subcontractor to North American Rockwell (NAR) of Downey, California, prime contractor for the CSM. It contained two thermostatic switches, originally designed for the command module's 28-volt DC power, but which could fail if subjected to the 65 volts used during ground testing at KSC. Under the original 1962 specifications, the switches would be rated for 28 volts, but revised specifications issued in 1965 called for 65 volts to allow for quicker tank pressurization at KSC. Nonetheless, the switches Beech used were not rated for 65 volts.

At NAR's facility, Oxygen Tank 2 had been originally installed in an oxygen shelf placed in the Apollo 10 service module, SM-106, but was removed to fix a potential electromagnetic interference problem and another shelf substituded. During removal, the shelf was accidentally dropped at least 2 inches (5 cm) because a retaining bolt had not been removed. The probability of damage from this was low, but it is possible that there was a loosely-fitting fill line whose fit was made worse by the fall. After some retesting (which did not include filling the tank with liquid oxygen), in November 1968 the shelf was re-installed in SM-109, intended for Apollo 13, which was shipped to KSC in June 1969.

Panel similar to the SM Sector 4 cover being ejected during a test performed as part of the investigation

After the tank was filled during the Countdown Demonstration Test, which began on March 16, 1970, it could not be emptied through the normal drain line, and a report was written. After discussion among NASA and the contractors, attempts to empty the tank resumed on March 27. When it would not empty normally, the heaters in the tank were turned on to boil off the oxygen. The thermostatic switch was designed to prevent the heaters from raising the temperature higher than 80 °F (27 °C), but it failed under the 65V power supply applied. Temperatures on the heater tube within the tank may have reached 1,000 °F (538 °C), most likely damaging the Teflon insulation. The temperature gauge was not designed to read higher than 85 °F (29 °C), so the technician monitoring the procedure detected nothing unusual. This heating had been approved by Lovell and Mattingly of the prime crew, as well as by NASA managers and engineers. But once the tank was refilled with oxygen prior to the launch of Apollo 13, and electric power was connected to it, it was in a hazardous condition. The board found that Swigert's activation of the Oxygen Tank 2 fan at the request of Mission Control caused an electrical arc that set the tank on fire.

The board conducted a test of an oxygen tank rigged with hot-wire ignitors that caused a rapid rise in temperature within the tank, after which it failed, producing telemetry similar to that seen with the Apollo 13 Oxygen Tank 2. Tests with panels similar to the one that was seen to be missing on SM Sector 4 caused separation of the panel in the test apparatus.

Changes in response

Redesigned oxygen tank for Apollo 14

For Apollo 14, the oxygen tank was redesigned, with the thermostats upgraded to handle the proper voltage. The heaters were retained since they were necessary to maintain oxygen pressure. The stirring fans, with their unsealed motors, were removed, which meant the oxygen quantity gauge was no longer accurate. This required adding a third tank so that no tank would go below half full. The quantity probe was upgraded from aluminum to stainless steel. The third tank was placed in Bay 1 of the SM, on the side opposite the other two, and was given an isolation valve that could isolate it from the fuel cells and from the other two oxygen tanks in an emergency, and allow it to feed the CM's environmental system only.

All electrical wiring in Bay 4 was sheathed in stainless steel. The fuel cell oxygen supply valves were redesigned to isolate the Teflon-coated wiring from the oxygen. The spacecraft and Mission Control monitoring systems were modified to give more immediate and visible warnings of anomalies. An emergency supply of 5 US gallons (19 L) of water was stored in the CM, and an emergency battery, identical to those that powered the LM's descent stage, was placed in the SM. The LM was modified to make easier transfer of power from LM to CM. Devices were placed in the S-II second stage to counteract pogo vibrations.

Mission notes

President Richard Nixon awarding the Apollo 13 astronauts the Presidential Medal of Freedom

"Towing bill" rendered by Grumman to Rockwell

Apollo 13 was called a "successful failure" by Lovell. It has been repeatedly called, "NASA's finest hour".

On February 5, 1971, Apollo 14's LM, Antares, landed on the Moon with astronauts Alan Shepard and Ed Mitchell aboard, near Fra Mauro, the site Apollo 13 had been intended to explore. The Lunar Atmosphere Detector, also called the Cold Cathode Gauge Experiment (CCGE), which was part of the Apollo Lunar Surface Experiment Package on Apollo 13, was not flown again. It was a version of the Cold Cathode Ion Gauge (CCIG) which featured on Apollo 12, Apollo 14, and Apollo 15. The CCGE was designed as a standalone version of the CCIG. On other missions, the CCIG was connected as part of the Suprathermal Ion Detector (SIDE). Because of the aborted landing, this experiment was never deployed.

The Guinness Book of World Records lists the Apollo 13 mission as the absolute altitude record holder for a crewed spacecraft: 400,171 kilometers (248,655 mi) from Earth at 7:21 pm EST, April 14 (00:21:00 UTC April 15). The primary factor was that the Moon was nearly at apogee during the mission. Apollo 13's unique free return trajectory caused it to go approximately 100 km (60 mi) further from the lunar far side than other Apollo lunar missions, but this was a minor contribution to the record. A reconstruction of the trajectory by astrodynamicist Daniel Adamo in 2009 records the furthest distance as 400,046 kilometers (248,577 mi) at 7:34 pm EST (00:34:13 UTC). Apollo 10 holds the record for second furthest at a distance of 399,806 kilometers (248,428 mi).

As a joke, Grumman issued an invoice to North American Rockwell, prime contractor for the CSM, for "towing" the CSM most of the way to the Moon and back. Line items included 400,001 miles (643,739 km) at $1 per mile (plus $4 for the first mile); $536.05 for battery charging; oxygen; and four nights at $8 per night for an "additional guest in room" (Swigert). After a 20% "commercial discount", and a 2% discount for timely payment, the final total was $312,421.24. North American declined payment, noting that it had ferried three previous Grumman LMs to the Moon without compensation.

Hardware disposition

The Apollo 13 command module Odyssey on display at the Cosmosphere in Hutchinson, Kansas

The command module shell was formerly at the Musée de l'air et de l'espace, in Paris. The interior components were removed during the investigation of the accident and reassembled into boilerplate BP-1102A, the water egress training module, and were subsequently on display at the Museum of Natural History and Science in Louisville, Kentucky, until 2000. The command module and the internal components were reassembled, and Odyssey is currently on display at the Cosmosphere in Hutchinson, Kansas.

The lunar module Aquarius re-entered Earth's atmosphere on April 17, 1970. Any surviving pieces fell into the deep ocean off the coast of New Zealand. Apollo 13's final midcourse correction had addressed the concerns of the Atomic Energy Commission, who wanted the cask containing the plutonium oxide intended for the SNAP-27 reactor to impact in a safe place. The LM's remains fell to Earth over the Tonga Trench in the Pacific, one of its deepest points, and sank 10 kilometers to the bottom. Later helicopter surveys found no radioactive leakage.

Lovell's lunar space suit helmet, one of his gloves, and the plaque that had been intended to be left on the Moon are on exhibit at the Adler Planetarium in Chicago, Illinois.

Mission insignia and call signs

Apollo 13 flown silver Robbins medallion

The Apollo 13 mission insignia depicts the Greek god of the Sun, Apollo, with three horses pulling his chariot across the face of the Moon, and the Earth seen in the distance. This is meant to symbolize the Apollo flights bringing the light of knowledge to all people. The motto, Ex luna, scientia means "From the Moon, knowledge"; Lovell adapted the motto of his alma mater, the Naval Academy, Ex scientia, trident (From knowledge, sea power).

On the patch, the mission number appeared in Roman numerals as Apollo XIII. It did not have to be modified after Mattingly's replacement by Swigert since it is one of only two Apollo mission insignia—the other being Apollo 11—not to include the names of the crew. It was designed by artist Lumen Martin Winter, who based it on a mural he had painted for The St. Regis Hotel in New York City. The mural was later purchased by actor Tom Hanks, who portrayed Lovell in the movie Apollo 13, and was on the wall of a restaurant near Chicago owned by Lovell's son. After the restaurant closed down, Lovell had it installed in the Capt. James A. Lovell Federal Healthcare Center.

The motto was in Lovell's mind when he chose the call sign Aquarius for the lunar module, taken from Aquarius, the bringer of water. Some from the media erroneously reported that the call sign was taken from a song by that name from the musical Hair. The command module's call sign, Odyssey, was chosen not only for its Homeric association but to refer to the recent movie, 2001: A Space Odyssey, based on a short story by science fiction author Arthur C. Clarke. In his book, Lovell indicated he chose the name Odyssey because he liked the word and its definition: a long voyage with many changes of fortune.

The support crews for the Apollo missions were astronauts, usually low in seniority, who assembled the mission's rules, flight plan, and checklists, and kept them updated; for Apollo 13, they were Vance D. Brand, Jack Lousma and William R. Pogue.

The CAPCOMs (the individual in Mission Control responsible for voice communications with the crew, and by tradition an astronaut) were Kerwin, Brand, Lousma, Young and Mattingly.

Popular culture and media

The 1974 movie Houston, We've Got a Problem, while set around the Apollo 13 incident, is a fictional drama about the crises faced by ground personnel when the emergency disrupts their work schedules and places additional stress on their lives; only a couple news clips and a narrator's solemn voice deal with the actual crisis. Lovell publicly complained about the movie, saying it was "fictitious and in poor taste."

"Houston ... We've Got a Problem" was the title of an episode of the BBC documentary series A Life At Stake, broadcast in March 1978. This was an accurate, if simplified, reconstruction of the events. In 1994, during the 25th anniversary of Apollo 11, PBS released a 90-minute documentary titled Apollo 13: To the Edge and Back.

Following the flight, the crew planned to write a book, but they all left NASA without starting it. After Lovell retired in 1991, he was approached by journalist Jeffrey Kluger about writing a non-fiction account of the mission. Swigert died in 1982 and Haise was no longer interested in collaborating on a book. The resultant book, Lost Moon: The Perilous Voyage of Apollo 13, was published in 1994.

The next year, in 1995, a film adaptation of the book, Apollo 13, was released, directed by Ron Howard and starring Tom Hanks as Lovell, Bill Paxton as Haise, Kevin Bacon as Swigert, Gary Sinise as Mattingly, Ed Harris as Kranz, and Kathleen Quinlan as Marilyn Lovell. James Lovell, Eugene Kranz, and other principals have stated that this film depicted the events of the mission with reasonable accuracy, given that some dramatic license was taken. For example, the film changes the tense of Lovell's famous follow-up to Swigert's original words from, "Houston, we've had a problem" to "Houston, we have a problem". The film also invented the phrase "Failure is not an option", uttered by Harris as Kranz in the film; the phrase became so closely associated with Kranz that he used it for the title of his 2000 autobiography. The film won two of the nine Academy Awards it was nominated for, Best Film Editing and Best Sound.

In the 1998 miniseries From the Earth to the Moon, co-produced by Hanks and Howard, the mission is dramatized in the episode "We Interrupt This Program". Rather than showing the incident from the crew's perspective as in the Apollo 13 feature film, it is instead presented from an Earth-bound perspective of television reporters competing for coverage of the event.

In 2008, an interactive theatrical show titled Apollo 13: Mission Control premiered at BATS Theatre in Wellington, New Zealand. The production faithfully recreated the mission control consoles and audience members became part of the storyline. The show also featured a "guest" astronaut each night: a member of the public who suited up and amongst other duties, stirred the oxygen tanks and said the line "Houston, we've had a problem." This "replacement" astronaut was a nod to Swigert, who replaced Mattingly shortly before launch. The production toured to other cities extensively in New Zealand and Australia in 2010–2011. The production traveled to the US and performed 45 shows in 2012.

Gallery

• 
  The "mailbox" at Mission Control during the Apollo 13 mission
• 
  The crew on board the USS Iwo Jima following splashdown
• 
  Lunar module Aquarius after it was jettisoned above the Earth
• The service module (SM) and lunar module (LM) as they burned up reentering Earth's atmosphere over the Pacific Ocean
  The service module (SM) and lunar module (LM) as they burned up reentering Earth's atmosphere over the Pacific Ocean
• 
  Mission Control celebrates the successful splashdown
• 
  The crew speaking with President Nixon shortly after their return
• 
  Replica of the plaque with Swigert's name that was to cover the one attached to Aquarius with Mattingly's name

See also

• List of artificial objects on the Moon

Sources

• Adamo, Daniel (2009). "The Elusive Human Maximum Altitude Record". Quest: The History of Spaceflight Quarterly. Vol. 16, no. 4. ISSN 1065-7738.{{cite magazine}}: CS1 maint: ref duplicates default (link)
• Apollo 13 Press Kit (PDF). Washington, D.C.: NASA. 1970. 70-50K.
• Apollo 14 Press Kit (PDF). Washington, D.C.: NASA. 1971. 71-3K.
• Barell, John (2016). Antarctic Adventures: Life Lessons from Polar Explorers. Balboa Press. ISBN 978-1504366519.{{cite book}}: CS1 maint: ref duplicates default (link)
• Benson, Charles D.; Faherty, William Barnaby (1978). Moonport: A History of Apollo Launch Facilities and Operations (PDF). NASA History Series. Washington, DC. SP-4204. {{cite book}}: |website= ignored (help)CS1 maint: location missing publisher (link)
• Chaikin, Andrew (1998) [1994]. A Man on the Moon: The Voyages of the Apollo Astronauts. New York: Penguin Books. ISBN 978-0-14-024146-4.{{cite book}}: CS1 maint: ref duplicates default (link)
• Cooper, Henry S. F. Jr. (2013) [1972]. Thirteen: The Apollo Mission that Failed. New York, NY: Open Road Integrated Media, Inc. ISBN 978-1-4804-6221-2.{{cite book}}: CS1 maint: ref duplicates default (link)
• Cortright, Edgar M. (June 15, 1970). Report of Apollo 13 Review Board (PDF). NASA.
  • Report of Apollo 13 Review Board, appendix F–H (PDF).
• Driscoll, Everly (April 4, 1970). "Apollo 13 to the highlands". Science News. 97 (14): 353–355. doi:10.2307/3954891. JSTOR 3954891.(subscription required)
• Flight Control Division (April 1970). Mission Operations Report (PDF). Houston, Texas: NASA Manned Spacecraft Center.
• Gatland, Kenneth (1976). Manned Spacecraft (Second ed.). New York: MacMillan. ISBN 0-02-542820-9.{{cite book}}: CS1 maint: ref duplicates default (link)
• Glenday, Craig, ed. (2010). Guinness World Records 2010. New York: Bantam Books. ISBN 978-0-553-59337-2.{{cite book}}: CS1 maint: ref duplicates default (link)
• Harland, David (1999). Exploring the Moon: The Apollo Expeditions. London; New York: Springer. ISBN 978-1-85233-099-6.{{cite book}}: CS1 maint: ref duplicates default (link)
• Houston, Rick; Heflin, J. Milt; Aaron, John (2015). Go, Flight!: the Unsung Heroes of Mission Control, 1965–1992 (eBook ed.). Lincoln, NE: University of Nebraska Press. ISBN 978-0-8032-8494-4.
• Houston, We've Got a Problem (PDF). Washington, D.C.: NASA Office of Public Affairs. 1970. EP-76.
• Kranz, Gene (2000). Failure Is Not an Option: Mission Control from Mercury to Apollo 13 and Beyond. Simon & Schuster. ISBN 0743200799.{{cite book}}: CS1 maint: ref duplicates default (link)
• Larsen, Curtis E. (May 22, 2008). NASA Experience with Pogo in Human Spaceflight Vehicles (PDF). NATO RTO Symposium ATV-152 on Limit-Cycle Oscillations and Other Amplitude-Limited, Self-Excited Vibrations. NASA Johnson Space Center. Norway. RTO-MP-AVT-152.{{cite conference}}: CS1 maint: ref duplicates default (link)
• Lovell, Jim; Kluger, Jeffrey (2000) [1994]. Lost Moon: The Perilous Voyage of Apollo 13. Houghton Mifflin. ISBN 0618056653.
• Lovell, James A. (1975). "Chapter 13: "Houston, We've Had a Problem"" (PDF). In Cortright, Edgar M. (ed.). Apollo Expeditions to the Moon (PDF). Washington, D.C.: NASA. SP-350.
• Mission Evaluation Team (September 1970). Apollo 13 Mission Report (PDF). Houston, Texas: NASA Manned Spacecraft Center. MSC-02680.
• Orloff, Richard W.; Harland, David M. (2006). Apollo: The Definitive Sourcebook. Chichester, UK: Praxis Publishing Company. ISBN 978-0-387-30043-6.
• Orloff, Richard W. (2000). Apollo by the Numbers: A Statistical Reference (PDF). NASA History Series. Washington, DC: NASA History Division, Office of Policy and Plans. ISBN 978-0-16-050631-4. LCCN 00061677. OCLC 829406439. NASA SP-2000-4029.{{cite book}}: CS1 maint: ref duplicates default (link)
• Phinney, William C. (2015). Science Training History of the Apollo Astronauts (PDF). NASA. SP-2015-626.{{cite book}}: CS1 maint: ref duplicates default (link)
• Slayton, Donald K. "Deke"; Cassutt, Michael (1994). Deke! U.S. Manned Space: From Mercury to the Shuttle (1st ed.). New York: Forge. ISBN 9780312855031.
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Further reading

• Lattimer, Dick (1985). All We Did Was Fly to the Moon. History-alive series. Vol. 1. Foreword by James A. Michener (1st ed.). Alachua, FL: Whispering Eagle Press. ISBN 0-9611228-0-3. LCCN 85222271.

External links

NASA reports

• The Apollo Spacecraft – A Chronology NASA SP-4009, vol. IV, pt. 3
• "Apollo Program Summary Report" (PDF), NASA, JSC-09423, April 1975
• "Apollo 13: Lunar exploration experiments and photography summary" (Original mission as planned) (PDF) NASA, February 1970
• "Apollo 13 Technical Air-to-Ground Voice Transcription" (PDF) NASA, April 1970

Multimedia

• "Space Educators' Handbook Apollo 13" at NASA
• "Apollo 13: LIFE With the Lovell Family During 'NASA's Finest Hour'" – slideshow by Life magazine
• "Apollo 13: NASA's Finest Hour" – slideshow by Life magazine at the Internet Archive