Damage to Apollo 13’s Service Module, photographed just after separation 17 April 1970. (NASA Apollo 13 Image Library AS13-59-8500)
13 April 1970: At 10:07:53 p.m. Eastern Standard Time (mission elapsed time 55:54:53), while Apollo 13 and its crew, James A. Lovell, Jr., John L. Swigert and Fred W. Haise, were approximately 200,000 miles (322,000 kilometers) from Earth enroute to a landing at the Fra Mauro Highlands on The Moon, an internal explosion destroyed the Number 2 oxygen tank¹ in the spacecraft’s Service Module. The Number 1 tank was also damaged. Two of three fuel cells that supplied electrical power to the spacecraft failed.
Jack Swigert radioed Mission Control: “I believe we’ve had a problem here.” ²
Mission Control: “This is Houston. Say again, please.”
Jim Lovell: “Houston, we’ve had a problem. Main B Bus undervolt.”
With oxygen supplies depleted and power failing, the lunar landing mission had to be aborted, and the three-man crew evacuated the Command Module and took shelter in the Lunar Module.
This was a life-threatening event.
The story of Apollo 13 and its crew and their journey home is well known. The 1995 Ron Howard/Universal Pictures film, “Apollo 13,” takes some artistic license, but is generally accurate and realistic.
Flight Director Gene Kranz (right of center, with his back to the camera) in Mission Control, Houston, Texas, a few minutes before the accident. (NASA Apollo 13 Image Library Image AP13-S70-35139)
Five years before Apollo 13 was launched, an engineering decision had been made to increase the spacecraft electrical system from 28 volts to 65 volts. This required that every electrical component on the vehicle had to be changed to accommodate the increased power. The after-accident investigation found that the team that designed the cooling fans for the oxygen tanks was never informed of the change.
During the actual flight, the wiring inside the tank heated to approximately 1,000 °F. (538 °C.), and in the pressurized pure oxygen, the insulation caught fire. The tank, originally installed on Apollo 10, had been dropped when it was removed for modification. It was repaired and later used on Apollo 13, however, it had been weakened by the damage. The extreme pressure caused by the heat of the burning electrical wiring in the containment caused the tank to rupture.
The damaged Service Module after being jettisoned from the Command Module, photographed from the Lunar Module. The Moon is visible between the two. (NASA)
¹ Serial number 10024X-TA0009
² The official mission transcript attributes this statement to Jim Lovell, however, in Lovell’s recollection, it was made by Swigert.
Apollo 13 (AS-508) lifts off from Launch Complex 39A at the Kennedy Space Center, Cape Canaveral, Florida, 19:13:00 UTC, 11 April 1970. (NASA)
11 April 1970: At 2:13:00 p.m., Eastern Standard Time, Apollo 13 was launched from Launch Complex 39A at the Kennedy Space Center, Cape Canaveral, Florida. This mission was planned to be the third manned lunar landing. The destination was the Fra Mauro Highlands. In command was Captain James A. Lovell, Jr., United States Navy. The Command Module Pilot was John L. “Jack” Swigert, Jr. (who was originally scheduled as the backup CSM pilot, but had replaced Lieutenant Commander T. Kenneth Mattingly II, USN, just three days before launch). and the Lunar Module Pilot was Fred W. Haise, Jr., A NASA astronaut (formerly a U.S. Marine Corps and U.S. Air Force fighter pilot, test pilot and instructor).
Apollo 13 flight crew, left to right: James A. Lovell, Jr., John L. Swigert, Jr., Fred W. Haise, Jr. (NASA)
The crew change had been made because it was believed that Ken Mattingly had been exposed to measles and NASA administrators did not want to risk that he might become ill during the flight.
The F-1 engines of the S-IC first stage shut down at 2 minutes, 43.6 seconds. After being jettisoned, the first stage continued on a ballistic trajectory and fell into the Atlantic Ocean at 000:09:52.64, 355.3 nautical miles (408.9 statute miles/658.0 kilometers) from the launch site.
At T + 000:05:30.64, while accelerating toward Earth orbit, the center J-2 engine on the Saturn S-II second stage shut down 2 minutes, 12.36 seconds early, which required the other four engines to increase their burn by 34.53 seconds, and the S-IVB third stage engine had to burn 9 seconds seconds longer than planned to achieve the necessary velocity for orbital insertion. The second stage traveled 2,452.6 nautical miles (2,822.4 statute miles/4,542.2 kilometers) before hitting the Atlantic’s surface at T + 20 minutes, 58.1 seconds.
Following the Trans Lunar Injection maneuver, Apollo 13’s S-IVB third stage was intentionally crashed into the lunar surface. The impact took place at 00:09:41 UTC, 15 April. The stage was traveling at 5,600 miles per hour (9,012 kilometers per hour). The energy at impact was equivalent to the explosion 7.7 tons of TNT.
The Apollo 13 mission did not go as planned. An explosion inside the service module was a very near disaster, and the lunar landing had to be aborted. Returning the three astronauts safely to Earth became the primary task.
Damage to Apollo 13’s Service Module, photographed just after separation. (NASA)
The Saturn V rocket was a three-stage, liquid-fueled heavy launch vehicle. Fully assembled with the Apollo Command and Service Module, it stood 363 feet (110.642 meters) tall. The first and second stages were 33 feet (10.058 meters) in diameter. Fully loaded and fueled the rocket weighed 6,200,000 pounds (2,948,350 kilograms). It could lift a payload of 260,000 pounds (117,934 kilograms) to Low Earth Orbit.
Apollo 13/Saturn V (AS-508) during rollout, 16 December 1969. (NASA 69-HC-1269)
The first stage was designated S-IC. It was designed to lift the entire rocket to an altitude of 220,000 feet (67,056 meters) and accelerate to a speed of more than 5,100 miles per hour (8,280 kilometers per hour). The S-IC stage was built by Boeing at the Michoud Assembly Facility, New Orleans, Louisiana. It was 138 feet (42.062 meters) tall and had an empty weight of 290,000 pounds (131,542 kilograms). Fully fueled with 203,400 gallons (770,000 liters) of RP-1 and 318,065 gallons (1,204,000 liters) of liquid oxygen, the stage weighed 5,100,000 pounds (2,131,322 kilograms). It was propelled by five Rocketdyne F-1 engines, producing 1,522,000 pounds of thrust, each, for a total of 7,610,000 pounds of thrust at Sea Level. These engines were ignited seven seconds prior to lift off and the outer four burned for 168 seconds. The center engine was shut down after 142 seconds to reduce the rate of acceleration. The F-1 engines were built by the Rocketdyne Division of North American Aviation at Canoga Park, California.
Saturn V first stage Rocketdyne F-1 engines running, producing 7.5 million pounds of thrust. Ice falls from the rocket. The hold-down arms have not yet been released. (NASA)
The S-II second stage was built by North American Aviation at Seal Beach, California. It was 81 feet, 7 inches (24.87 meters) tall and had the same diameter as the first stage. The second stage weighed 80,000 pounds (36,000 kilograms) empty and 1,060,000 pounds loaded. The propellant for the S-II was liquid hydrogen and liquid oxygen. The stage was powered by five Rocketdyne J-2 engines, also built at Canoga Park. Each engine produced 232,250 pounds of thrust, and combined, 1,161,250 pounds of thrust.
The Saturn V third stage was designated S-IVB. It was built by McDonnell Douglas Astronautics Company at Huntington Beach, California. The S-IVB was 58 feet, 7 inches (17.86 meters) tall with a diameter of 21 feet, 8 inches (6.604 meters). It had a dry weight of 23,000 pounds (10,000 kilograms) and fully fueled weighed 262,000 pounds. The third stage had one J-2 engine and also used liquid hydrogen and liquid oxygen for propellant. The S-IVB would place the Command and Service Module into Low Earth Orbit, then, when all was ready, the J-2 would be restarted for the Trans Lunar Injection.
Eighteen Saturn V rockets were built. They were the most powerful machines ever built by man.
Apollo 9 Saturn V (AS-504) launches from Pad 39A, at 11:00:00 a.m., EST, 3 March 1969. (NASA)
3 March 1969: At 11:00:00 a.m. Eastern Standard Time (16:00:00 UTC), Apollo 9 Saturn V (AS-504), the second manned Saturn V rocket, is launched from Launch Complex 39A at the Kennedy Space Center, Cape Canaveral, Florida. Aboard are astronauts Colonel James Alton McDivitt, U.S. Air Force, the Spacecraft Commander; Colonel David Randolph Scott, U.S. Air Force, Command Module Pilot; and Mr. Russell Louis Schweickart (formerly an Air Force pilot), Lunar Module Pilot. McDivitt and Scott were on their second space flight. Rusty Schweickert was on his first.
The 10-day Earth orbital mission is used to test docking-undocking with the lunar module, and to certify the LM as flight-worthy. This was necessary before the program could proceed to the next phase: The Moon.
The flight crew of Apollo 9, James A. McDivitt, David R. Scott and Russell L. Schweickart. AS-504 is in the background. (NASA)
The Apollo Command/Service Module was built by the Space and Information Systems Division of North American Aviation, Inc., at Downey, California.
The SPS engine was an AJ10-137, built by Aerojet General Corporation of Azusa, California. It burned a hypergolic fuel combination of Aerozine 50 and nitrogen tetraoxide, producing 20,500 pounds of thrust (91.19 kilonewtons). It was designed for a 750 second burn, or 50 restarts during a flight.
Astronaut David R. Scott stands in the open hatch of the Apollo Command Module “Gumdrop” in Earth Orbit, 6 March 1969. (Russell L. Schweickart/NASA)
The Apollo Lunar Module was built by Grumman Aerospace Corporation to carry two astronauts from lunar orbit to the surface, and return. There was a descent stage and ascent stage. The LM was intended only for operation in the vacuum of space, and was expended after use.
Three-view drawing of the Lunar Module with dimensions. (NASA)
The LM was 23 feet, 1 inches (7.036 meters) high with a maximum landing gear spread of 31 feet (9.449 meters). It weighed 33,500 pounds (15,195 kilograms). The spacecraft was designed to support the crew for 48 hours, though in later missions, this was extended to 75 hours.
The Descent Stage was powered by a single TRW LM Descent Engine. The LMDE used hypergoloc fuel and was throttleable. It produced from 1,050 pounds of thrust (4.67 kilonewtons) to 10,125 pounds (45.04 kilonewtons). The Ascent Stage was powered by a Bell Aerospace Lunar Module Ascent Engine. This also used hypergolic fuels. It produced 3,500 pounds of thrust (15.57 kilonewtons).
Apollo 9 Lunar Module “Spider” (Apollo LM-3) in Earth orbit, 7 March 1969. (Dave Scott/NASA)
The Saturn V rocket was a three-stage, liquid-fueled heavy launch vehicle. Fully assembled with the Apollo Command and Service Module, it stood 363 feet (110.642 meters) tall. The first and second stages were 33 feet (10.058 meters) in diameter. Fully loaded and fueled the rocket weighed 6,200,000 pounds (2,948,350 kilograms). It could lift a payload of 260,000 pounds (117,934 kilograms) to Low Earth Orbit.
The first stage was designated S-IC. It was designed to lift the entire rocket to an altitude of 220,000 feet (67,056 meters) and accelerate to a speed of more than 5,100 miles per hour (8,280 kilometers per hour). The S-IC stage was built by Boeing at the Michoud Assembly Facility, New Orleans, Louisiana. It was 138 feet (42.062 meters) tall and had an empty weight of 290,000 pounds (131,542 kilograms). Fully fueled with 203,400 gallons (770,000 liters) of RP-1 and 318,065 gallons (1,204,000 liters) of liquid oxygen, the stage weighed 5,100,000 pounds (2,131,322 kilograms). It was propelled by five Rocketdyne F-1 engines, producing 1,522,000 pounds of thrust (6770.19 kilonewtons), each, for a total of 7,610,000 pounds of thrust at Sea Level (33,850.97 kilonewtons). These engines were ignited seven seconds prior to lift off and the outer four burned for 168 seconds. The center engine was shut down after 142 seconds to reduce the rate of acceleration. The F-1 engines were built by the Rocketdyne Division of North American Aviation at Canoga Park, California.
The S-II second stage was built by North American Aviation at Seal Beach, California. It was 81 feet, 7 inches (24.87 meters) tall and had the same diameter as the first stage. The second stage weighed 80,000 pounds (36,000 kilograms) empty and 1,060,000 pounds loaded. The propellant for the S-II was liquid hydrogen and liquid oxygen. The stage was powered by five Rocketdyne J-2 engines, also built at Canoga Park. Each engine produced 232,250 pounds of thrust (1,022.01 kilonewtons), and combined, 1,161,250 pounds of thrust (717.28 kilonewtons).
The Saturn V third stage was designated S-IVB. It was built by McDonnell Douglas Astronautics Company at Huntington Beach, California. The S-IVB was 58 feet, 7 inches (17.86 meters) tall with a diameter of 21 feet, 8 inches (6.604 meters). It had a dry weight of 23,000 pounds (10,000 kilograms) and fully fueled weighed 262,000 pounds. The third stage had one J-2 engine and also used liquid hydrogen and liquid oxygen for propellant. The S-IVB would place the Command and Service Module into Low Earth Orbit, then, when all was ready, the J-2 would be restarted for the Trans Lunar Injection.
Eighteen Saturn V rockets were built. They were the most powerful machines ever built by man.
Apollo-Saturn IB AS-201 launch from Pad 34, Kennedy Space Center, 26 February 1966. (NASA)
26 February 1966: AS-201, the first Apollo/Saturn IB, was launched, carrying the first complete Block 1 Apollo Command and Service Module on an unmanned suborbital test flight. The launch took place at Launch Complex 34, Cape Kennedy Air Force Station, Cape Kennedy, Florida.
An illustration of an Apollo/Saturn IB space vehicle, with approximate dimensions. (Department of Special Collections, M. Louis Salmon Library, University of Alabama, via heroicrelics.org)
This flight was a demonstration of the combined Apollo Command Module and the Service Module. The second production Apollo capsule, CM-009, and the first production service module, SM-009, were launched by the first Saturn IB, SA-201.¹ (When combined, the capsule and service module are referred to as the CSM.)
The command to ignite the eight H-1 first stage engines was sent from the Mission Control Room at T-3.038 (16:11:56.962 UTC).² The engines ignited at T-2.45 and began to build thrust. First motion occurred at T+0.11.
Liftoff ³ was at 16:12:01.37 UTC, T+0.37. AS-201 climbed vertically for 11.2 seconds before beginning a pitch and roll maneuver which carried the space vehicle to its planned trajectory. Control of the mission was shifted from the Cape Kennedy Air Force Station to Mission Control at the Manned Spacecraft Center, Houston, Texas. Flight Director Glynn S. Lunney was now in charge.
AS-201 reached Mach 1 at T+65.7. The vehicle experienced its maximum dynamic pressure (max q) at T+77.7.
Maximum acceleration was reached at T+141.5, just as the first stage engines were shut down.
The S-IB first stage inner engines cutoff (IECO) occurred at T+141.5, and outer engine cutoff (OECO), at T+146.9. The vehicle had reached an altitude of 31.4 nautical miles (36.1 statute miles/58.2 kilometers) and was 33.9 nautical miles (39.0 statute miles/62.8 kilometers) downrange. It was traveling at 7,499.66 feet per second (5,113.4 miles per hour/8,229.2 kilometers per hour). The first stage was jettisoned.
Apollo/Saturn IB AS-201 first stage separation. (NASA)
The S-IVB second stage engine ignition occurred at T+149.3. The Launch Escape System (LES) was jettisoned at T+172.6. The vehicle continued to accelerate until its J-2 engine cut off at T+602.9. The vehicle had now reached an altitude of 141.2 nautical miles (162.5 statute miles/261.5 kilometers) and was 857.9 nautical miles (987.3 statute miles/1,588.8 kilometers) downrange, traveling 22,769.23 feet per second (15,524.5 miles per hour/24,984.2 kilometers per hour). The S-IVB and Command and Service Module separated at T+844.9.
The Apollo CSM reached a maximum altitude (apogee) of 265.7 nautical miles (305.8 miles/492.1 kilometers) at T+1020.0. As it began to descend, the Service Module’s Service Propulsion Subsystem (SPS) was tested. The SPS was powered by a non-throttleable, restartable, AJ10-137 rocket engine, built by Aerojet General Corporation of Azusa, California. This engine was fueled by Aerozine 50, a hypergolic 50:50 mixture of Unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide (N2O4). It produced 20,500 pounds of thrust (91.19 kilonewtons) in vacuum. It was designed for a 750 second burn, or 50 restarts during a flight. The first burn was from T+1211.2 –1395.2 (184 seconds), and the second, from T+1410.7–1420.7 (10 seconds). The engine did not operate exactly as planned during the flight. Thrust was erratic, possibly as a result of helium ingestion into the engine oxidizer feed line.
CM/SM separation occurred at T+1455.0, at an altitude of 138.9 nautical miles (159.8 statute miles/257.2 kilometers) and 3,660 nautical miles (4,211 statute miles/6,778 kilometers) down range. The command module was now traveling at a speed of 25968 fps (17,705 miles per hour/28,494 kilometers per hour). During reentry, the maximum deceleration was 14.3 gs. The Apollo capsule landed near Ascension Island in the South Atlantic Ocean, 4,577 nautical miles (5,267 statute miles/8,477 kilometers) from Cape Canaveral, and about 45 miles from the primary recovery ship. (S. 8.18°, W 11.15°) Total duration of the flight was 37 minutes, 19.7 seconds.
The Apollo spacecraft was recovered by USS Boxer (LPH- 4), a Wasp-class amphibious assault ship, and taken to Norfolk, Virginia.
Mission AS-201 was successful, though several problems occurred during the flight. These were identified and corrected on the following production vehicles.
Apollo/Saturn IB AS-201 at Launch Complex 34, 4 February 1966. (NASA S-66-21307)
Apollo/Saturn IB AS-201 was approximately 223 feet, 4 inches (68.072 meters) tall. The total vehicle weight was 1,320,220 pounds (598,842 kilograms).
The Apollo command module of AS-201 was Spacecraft 009 (CM-009), a Block I capsule. (Various crew equipment had not been installed for this test flight.) The Apollo was a conical space capsule designed and built by North American Aviation’s Space and Information Systems Division in Downey, California, to carry a crew of three astronauts on space missions of two weeks or longer. The capsule had a length of 11 feet, 1.5 inches (3.3909 meters) and maximum diameter of 12 feet, 10 inches (3.9116 meters). The service module, also built by North American Aviation, was 12 feet, 11 inches (3.937 meters) long and 12 feet, 10 inches (3.9116 meters) in diameter.
Construction of CM-009 began in 1963. It was accepted 20 October 1965 and shipped to the Kennedy Space Center, arriving at the Manned Spacecraft Operations Building (MSOB) on 25 October. The CSM was stacked on the vehicle 26 December 1965. The Launch Escape System was added 24 January 1966.
Between the CSM and the Saturn IB was the Spacecraft-Lunar Module Adapter (SLA) structure, also built by NAA. This conical section had a length of 28 feet, 0 inches (8.5344 meters) and tapered from a diameter of 12 feet, 10 inches (3.9116 meters) to 21 feet, 8 inches (6.604 meters). No Lunar Module was carried on this flight.
Saturn IB SA-201 at Launch Complex 34. The launch vehicle consists of an S-IB first stage, S-IVB second stage, and an Instrumentation Unit. (NASA 65-H-2067)
The Saturn IB two-stage launch vehicle was numbered SA-201. It consisted of an S-IB first stage, an S-IVB second stage, an Instrumentation Unit, and various fairings and adapters. It was capable of launching a 46,000 pound (20,865 kilogram) payload to Earth orbit.
The Saturn IB SA-201 S-IB first stage is lifted onto Launch Pad 34, 19 August 1965. Several of the stage’s eight stabilizing fins are not present during this maneuver. (NASA KSC-65C-5347)
The S-IB first stage was built by Chrysler Corporation Space Division at the Michoud Assembly Facility near New Orleans, Louisiana. The S-IB was 80 feet, 2 inches (24.435 meters) long, with a diameter of 21 feet, 5.0 inches (6.528 meters). The empty weight of this stage was 92,500 pounds (41,957 kilograms). Eight Redstone rocket fuel tanks containing the RP-1 fuel (a highly-refined kerosene) surrounded a Jupiter rocket tank containing the liquid oxygen oxidizer (LOX). It had a propellant capacity of 880,500 pounds (399,388 kilograms). The stage had eight stabilizing fins.
The S-IB was powered by eight Rocketdyne H-1 engines. The H-1s were built by the North American Aviation Rocketdyne Division, Canoga Park, California. Total thrust of the S-IB stage was 1,666,460 pounds (7,417.783 kilonewtons) at Sea Level,⁴ and it carried sufficient propellant for a maximum 4 minutes, 22.57 seconds of burn. This could lift the vehicle to an altitude of 37 nautical miles (69 kilometers).
A Saturn IB S-IVB second stage with its Rocketdyne J-2 engine and adapter section. (This S-IVB was part of Saturn IB SA-206.) (NASA 67-HC-26)
The S-IVB second stage was assembled at the Douglas Aircraft Company Missile & Space Division, Huntington Beach, California. The S-IVB was 61 feet, 4.555 inches (18.708497 meters) long, with a maximum diameter of 21 feet, 8.0 inches (6.604 meters). The second stage had an empty weight of 23,400 pounds (10,614 kilograms), and fuel capacity of 228,500 pounds (103,646 kilograms).
It was powered by a single Rocketdyne J-2 engine, fueled by liquid hydrogen (LH2) and LOX. The J-2 produced 229,714 pounds of thrust (1,021.819 kilonewtons), at high thrust, and 198,047 pounds (880.957 kilonewtons) at low thrust). The second stage carried enough fuel for 7 minutes, 49.50 seconds burn at high thrust.
The Instrumentation Unit, containing the Saturn’s guidance systems and attached to the top of the S-IVB stage, was designed by NASA’s Manned Space Flight Center (MSFC), and built by IBM at the Space Systems Center, Huntsville, Alabama. It was 3 feet, 0 inches (0.9 meters) tall with a diameter of 22 feet, 0 inches (6.7056 meters).
After being recovered, the AS-201 Apollo command module was used for drop tests. It is at the Strategic Air and Space Museum, Ashland, Nebraska.
Apollo Command Module CM-009 at the Strategic Air and Space Museum, Ashland, Nebraska. (HrAtsuo)
¹ NASA vehicle designations can sometimes be confusing. In this case, “AS-201” designates the all-up Apollo/Saturn IB Space Vehicle, number 201, including the first and second stages, the instrument package, lunar module adapter, service module, command module CM-009, and Launch Escape System (LES). “Spacecraft SC-009” refers to the LES, the CSM and the SLA. The “Saturn IB SA-201,” refers to just the two-stage launch vehicle, number 201: the S-IB first stage, S-IVB second stage, and the Instrumentation Unit. It does not include the payload.
² Range Zero, T-0 (“tee minus zero”), is the last full second before liftoff. This is the time reference for all mission events. In this case, T-0 was 16:12:01.000 UTC (11:12:01 a.m., Eastern Standard Time).
³ Lift off is defined as the instant of Instrumentation Unit umbilical disconnect. This is distinct from “First Motion.”
⁴ The total thrust the the eight H-1 engines of the S-IB first stage was only slightly more than that of just one of the five Rocketdyne F-1 engines of the Saturn V’s S-IC first stage booster.
Skylab in Earth orbit, as seen by the departing Skylab 4 mission crew, 8 February 1974. (NASA)
8 February 1974: At 02:33:12 UTC, the Skylab 4/Apollo command module undocked from the Skylab space station in Earth orbit, after 83 days, 4 hours, 38 minutes, 12 seconds. After several orbits, the Apollo capsule reentered the atmosphere and landed in the Pacific Ocean southwest of San Diego California, at 15:16:53 UTC. The crew was recovered by USS New Orleans (LPH-11), a helicopter carrier. Today, the Apollo capsule is displayed at the Smithsonian Institution National Air and Space Museum.
Skylab was an orbital laboratory built from a Saturn S-IVB third stage. It was launched from Cape Canaveral 14 May 1973 as part of a modified Saturn V rocket. The Skylab 4 crew was the third and final group of astronauts to live and the space station. (The mission insignia incorporates the numeral 3.)
Skylab’s orbit gradually decayed and it re-entered the atmosphere near Perth, Australia, 11 July 1979.
The Skylab 4 mission crew, left to right, Mission Commander Gerald P. Carr, Mission Scientist Edward G. Gibson and Pilot William R. Pogue. Pogue and Carr had joined NASA during the Apollo Program and were scheduled for Apollo 19, which was cancelled. This was the only space flight for these three astronauts. (NASA)
13 April 1970: At 10:07:53 p.m. Eastern Standard Time (mission elapsed time 55:54:53), while Apollo 13 and its crew, James A. Lovell, Jr., John L. Swigert and Fred W. Haise, were approximately 200,000 miles (322,000 kilometers) from Earth enroute to a landing at the Fra Mauro Highlands on The Moon, an internal explosion destroyed the Number 2 oxygen tank¹ in the spacecraft’s Service Module. The Number 1 tank was also damaged. Two of three fuel cells that supplied electrical power to the spacecraft failed.
