Apollo Program

The Apollo program is one of the most famous in American history, if not the history of the world, for it represents the first time any human set foot on an extraterrestrial land mass.

The Apollo program included a large number of uncrewed test missions and 12 crewed missions: Three Earth orbiting missions (Apollo 7, 9 and Apollo-Soyuz), two lunar orbiting missions (Apollo 8 and 10), a lunar swingby (Apollo 13), and six Moon landing missions (Apollo 11, 12, 14, 15, 16, and 17). Two astronauts from each of these six missions walked on the Moon (Neil Armstrong, Edwin Aldrin, Charles Conrad, Alan Bean, Alan Shepard, Edgar Mitchell, David Scott, James Irwin, John Young, Charles Duke, Gene Cernan, and Harrison Schmitt), the only humans to have set foot on another solar system body.

Apollo 15, 16, and 17 provided important data on geological features; it allowed the formation of theories as to the formation of the moon's core, mantle, and crust.

The twelve men who walked on the Moon between 1969 and 1972 brought back over 1/3 of a ton of moon rocks. Total funding for the Apollo program was approximately $20,443,600,000.

One of the worst tragedies in the history of spaceflight, Apollo 1 and crew were killed in a fire in the Apollo Command Module during a preflight test at Cape Canaveral. They were training for the first crewed Apollo flight, an Earth orbiting mission scheduled to be launched on February 21. They were taking part in a "plugs-out" test, in which the Command Module was mounted on the Saturn 1B on the launch pad just as it would be for the actual launch, but the Saturn 1B was not fueled. The plan was to go through an entire countdown sequence.

A number of minor problems cropped up which delayed the test considerably and finally a failure in communications forced a hold in the count at 5:40 P.M. At 6:31 one of the astronauts (probably Chaffee) reported, "Fire, I smell fire." Two seconds later White was heard to say, "Fire in the cockpit." The fire spread throughout the cabin in a matter of seconds. The last crew communication ended 17 seconds after the start of the fire, followed by loss of all telemetry. The Apollo hatch could only open inward and was held closed by a number of latches which had to be operated by ratchets. It was also held closed by the interior pressure, which was higher than outside atmospheric pressure and required venting of the command module before the hatch could be opened. It took at least 90 seconds to get the hatch open under ideal conditions.

Because the cabin had been filled with a pure oxygen atmosphere at normal pressure for the test and there had been many hours for the oxygen to permeate all the material in the cabin, the fire spread rapidly and the astronauts had no chance to get the hatch open. Nearby technicians tried to get to the hatch but were repeatedly driven back by the heat and smoke. By the time they succeeded in getting the hatch open roughly 5 minutes after the fire started the astronauts had already perished, probably within the first 30 seconds, due to smoke inhalation and burns.

The Apollo program was put on hold while an exhaustive investigation was made of the accident. It was concluded that the most likely cause was a spark from a short circuit in a bundle of wires that ran to the left and just in front of Grissom's seat. The large amount of flammable material in the cabin in the oxygen environment allowed the fire to start and spread quickly. A number of changes were instigated in the program over the next year and a half, including designing a new hatch which opened outward and could be operated quickly, removing much of the flammable material and replacing it with self-extinguishing components, using a nitrogen-oxygen mixture at launch, and recording all changes and overseeing all modifications to the spacecraft design more rigorously.

The mission, originally designated Apollo 204 but commonly referred to as Apollo 1, was officially assigned the name "Apollo 1" in honor of Grissom, White, and Chaffee. The first Saturn V launch (uncrewed) in November 1967 was designated Apollo 4 (no missions were ever designated Apollo 2 or 3). The Apollo 1 Command Module capsule 012 was impounded and studied after the accident and was then locked away in a storage facility at NASA Langley Research Center and later transferred to permanent storage with the debris from the Challenger accident in an abandoned missile silo at the Cape Canaveral Air Force Station, FL. The changes made to the Apollo Command Module as a result of the tragedy resulted in a highly reliable craft.

Apollo/Saturn 201 Lanuch from Kennedy Space Center

The unmanned Saturn/Apollo 4 mission was the first full test of the three stage Saturn V rocket. It carried a payload of an Apollo Command and Service Module (CSM) into Earth orbit. The mission was designed to test all aspects of the Saturn V launch vehicle and also returned pictures of Earth taken by the automatic Command Module apogee camera from about one hour before to one hour after apogee. Mission objectives included (and were considered successful:

Orbital insertion was achieved by ignition of the third (S-IVB) stage, putting the spacecraft (S-IVB and CSM) into a 184x192 km parking orbit with a period of 88.2 minutes and an inclination of 32.6°. After two orbits the S-IVB was re-ignited for a simulated translunar injection burn, putting the spacecraft into an Earth-intersecting trajectory with an apogee of 17,346 km. The S-IVB stage then separated from the CSM, and the service propulsion system (SPS) ignited for 16 seconds, raising the apogee to 18,216 km. Later the SPS was re-ignited for 271 seconds to accelerate the CSM to beyond lunar trajectory return velocities. SPS cutoff was followed by separation of the Command Module (CM) from the Service Module and orientation of the CM for reentry. Atmospheric entry at 122 km occurred at a flight path angle of 7.077° with a velocity of 11,140 m/s. The CM landed near Hawaii at about 16 km from the target landing point.

The unmanned Saturn/Apollo 5 was the first test flight of the Lunar Module (LM). Mission objectives were to verify the ascent and descent stages, the propulsion systems, and the restart operations, and to evaluate the spacecraft structure, LM staging, 2^nd stage (S-IVB) and instrument unit (IU) orbital performance.

After launch, the S-IVB 2^nd stage ignited to insert the spacecraft into a 163x222 km Earth orbit with a period of 88.3 minutes and an inclination of 31.63°. The nose cone was jettisoned and after a coast of 43 min 52 sec the LM was separated from the LM adapter. The LM entered a 167x222 km orbit with a period of 88.4 min and an inclination of 31.63°. A planned descent propulsion system (DPS) of 39 seconds was cut short after only 4 seconds. The burn was designed to simulate deceleration for descent to the lunar surface, but was stopped prematurely due to overly conservative programming of the flight software.

An alternate flight plan was put into effect, in which the DPS fired for 26 seconds at 10% thrust and then for 7 seconds at maximum thrust. A third DPS firing was performed 32 seconds later, consisting of a 26 second burn at 10% thrust and 2 seconds at maximum thrust, followed by a burn to simulate an abort during the landing phase, in which the ascent propulsion system (APS) was ignited simultaneously with the DPS being shut down. The APS burn lasted 60 seconds, followed by a 6 min 23 sec firing which depleted APS fuel. At the end of the 11 hr, 10 min test period, both LM stages were left in orbit eventually to reenter and disintegrate. Despite the initial premature DPS shutdown, the mission was deemed a success and operation of all LM systems was confirmed.

Three major problems occurred during the mission. Two minutes and five seconds after launch, the Saturn V structure underwent a severe pogo oscillation, without damage to the spacecraft structure. Due to a manufacturing flaw and unrelated to the pogo oscillations, structural panels were lost from the lunar module adapter. Finally, after the completion of first stage firing and part way through the second stage burn, two of the five second stage J-2 engines shut down prematurely.

The planned 175 km circular Earth orbit was not achieved, instead, after completion of the third stage burn, the spacecraft was in a 172.1x223.1 km, 89.8 min orbit. After two orbits, the third stage failed to re-ignite as planned, so the Service Module propulsion system was used to boost the spacecraft to an apogee of 22,225.4 km, from which the planned lunar reentry simulation took place at 36,025 km/hr, slightly less than the planned velocity of 40,000 km/hr. The Command Module splashed down 80 km off target 9 hr 50 min after launch and was recovered in good condition.

Launched October 11, 1968 at 15:02:45 UTC; landed October 22, 1968 at 11:11:48 UT
Crew: Walter Schirra, Jr. (Commander), Donn Eisele, and Walter Cunningham
Orbital Mass: 14,781 kg
Two photographic and three medical experiments were conducted by the crew, as well.

Apollo 7 was the first crewed flight of the Apollo spacecraft. The primary objectives of the Earth orbiting mission were to demonstrate Command and Service Module (CSM), crew, launch vehicle, and mission support facilities performance and to demonstrate CSM rendezvous capability. Two photographic experiments and three medical experiments were planned.

The command module (CM), a cone-shaped craft about 390 cm in diameter at the large end, served as a command, control, and communications center. Supplemented by the service module (SM), it provided all life support elements for the crew. The CM was capable of attitude control about three axes and some lateral lift translation. It also served as a buoyant vessel at sea. The SM provided the main propulsion and maneuvering capability. It was jettisoned just before CM reentry. The SM was a cylinder 390 cm in diameter and 670 cm long. There was no lunar module or boilerplate unit on this flight.

After launch, The S-IVB/CSM was put into a 228x282 km Earth orbit. Venting of S-IVB propellants raised the orbit to 232x309 km over the next three hours, at which time the S-IVB stage was separated from the CSM. The S-IVB stage was then used for rendezvous maneuvers over the next two days. Shortly after liftoff the commander, Schirra, reported he was developing a bad head cold. The next day the other two crew members also reported symptoms. The zero-gravity environment exacerbated the cold conditions because normal drainage of fluids from the head did not occur. Medication was taken, but the colds caused extreme discomfort to the crew throughout the mission. This hampered performance of some of the scheduled duties. During re-entry the astronauts did not wear their helmets to make it possible to properly clear their throats and ears.

Many tests were performed over the 11 day mission, including tests of sextant calibration, attitude control, evaporator, navigation, rendezvous radar, thermal control system, and service module propulsion systems. Seven television transmissions were made from Apollo 7, the first live TV transmissions from a piloted U.S. spacecraft. The S-IVB orbit decayed on October 18 and it impacted in the Indian Ocean at 9:30 UT. On October 22 at 10:46 UT the SM was jettisoned and re-entry of the CM and crew started 10 minutes later. Apollo 7 splashed down in the Atlantic Ocean on October 22, 1968 after a mission elapsed time of 260 hrs, 9 mins, 3 sec. The splashdown point was 27° 32 min N, 64° 04 min W, 200 nautical miles SSW of Bermuda and 13 km (8 mi) north of the recovery ship U.S.S. Essex. The Apollo 7 Command Module is on display at the Canada Science and Technology Museum, Ottawa, Canada.

This spacecraft was the first of the Apollo series to successfully orbit the moon, and the first manned spacecraft to leave Earth's gravity and reach the moon. The mission achieved operational experience and tested the Apollo command module systems, including communications, tracking, and life-support, in cis-lunar space and lunar orbit, and allowed evaluation of crew performance on a lunar orbiting mission. The crew photographed the lunar surface, both far side and nearside, obtaining information on topography and landmarks as well as other scientific information necessary for future Apollo landings. Additionally, six live television transmission sessions were done by the crew during the mission, including the famous Christmas Eve broadcast in which the astronauts read from the book of Genesis. All systems operated within allowable parameters and all objectives of the mission were achieved.

The Apollo 8 spacecraft consisted of a command module similar to Apollo 7 except that the forward pressure and ablative hatches were replaced by a combined forward hatch, which would be used for transfer to the Lunar Module on later missions. A Lunar Module was not used on the Apollo 8 mission but a Lunar Module Test Article which was equivalent in mass (9027 kg) to a Lunar Module was mounted in the spacecraft/launch vehicle adapter as ballast for mass loading purposes.

The spacecraft was launched on December 21, 1968, and was placed in a 190.6x183.2 km Earth parking orbit with a period of 88.2 minutes and an inclination of 32.51°. At 15:41:37 UT a third-stage burn injected the Apollo spacecraft into translunar trajectory. Orbit insertion took place on December 24 at 09:59:20 UT into an elliptical 310.6x111.2 km lunar orbit. Two orbits later a second burn placed Apollo 8 into a near-circular 110.4x112.3 km orbit for eight orbits. The trans-Earth injection burn took place on December 25 at 06:10:16 UT after a total of 10 lunar orbits.

Apollo 8 splashed down in the Pacific Ocean on December 27, 1968, after a mission elapsed time of 147 hrs, 0 mins, 42 sec. The splashdown point was 8° 7.5 min N, 165° 1.2 min W, 1,000 miles SSW of Hawaii and 5 km (3 mi) from the recovery ship U.S.S. Yorktown. The Apollo 8 Command Module is on display at the Chicago Museum of Science and Industry, Chicago, Illinois.

Apollo 9 was the third crewed Apollo flight and the first crewed flight to include the Lunar Module (LM). The primary objective of the mission was to test all aspects of the Lunar Module (LM) in Earth orbit, including operation of the LM as an independent self-sufficient spacecraft and performance of docking and rendezvous maneuvers. The goal was to simulate maneuvers which would be performed in actual lunar missions. Other concurrent objectives included overall checkout of launch vehicle and spacecraft systems, crew, and procedures. A multispectral photographic experiment was also performed.

Apollo 9 was composed of a command module, a command service module (CSM), a lunar module, and an instrument unit (IU), and was launched by a Saturn V rocket. The vehicle rocket had three stages, S-IC, S-II, and S-IVB. The CM, a cone-shaped craft about 390 cm in diameter at the large end, served as a command, control, and communications center. Supplemented by the SM, it provided all life support elements for the three crewmen. The CM was capable of attitude control about three axes and some lateral lift translation. It permitted LM attachment and CM/LM ingress and egress and served as a buoyant vessel at sea. The CSM provided the main propulsion and maneuvering capability. It was jettisoned just before CM reentry. The CSM was a cylinder 390 cm in diameter. The LM was a two-stage vehicle that accommodated two men and could transport them to the lunar surface. It had its own propulsion, communication, and life support systems.

After launch and injection of the combined S-IVB stage and the adaptor-LM-CSM payload into a 189.6x192.5 km Earth orbit, the S-IVB propellant tanks were vented, changing the orbit to 198x204 km. At 2:41 after launch the CSM separated from the S-IVB and and the adaptor panels were jettisoned, exposing the LM mounted on the S-IVB. The CSM turned around and docked with the LM at 3 hours after launch. At 4 hours after launch the S-IVB and CSM-LM were separated and the S-IVB had a 62 second burn to raise its apogee to 3050 km. Over the next few days the CSM service propulsion system (SPS) was fired five times to change the orbit to prepare for rendezvous maneuvers and test the dynamics of the CSM and LM under thrust. The LM descent engine was also fired for 367 seconds on March 5. On March 6, Schweickart conducted a 37.5 minute EVA on the LM porch to test the astronaut's portable life support system and extravehicular mobility unit. At the same time Scott performed an EVA from the CSM side hatch.

On March 7 at 13:03 UT, the LM, carrying McDivitt and Schweickart, separated from the CSM. It was put into a circular orbit about 20 km higher than the CSM. The LM descent stage was jettisoned and for the first time in space the ascent stage engine was fired, lowering the LM orbit to 16 km below and 120 km behind the CSM. A simulated rendezvous of the LM returning from a lunar mission with the orbiting CSM culminated in docking at 19:02 UT. The crew transferred back to the CSM, The LM ascent stage (1969-018C) was jettisoned and its ascent engine was commanded to fire to fuel depletion, into an Earth orbit of 235x6970 km. The LM ascent stage orbit decayed on October 23, 1981, and the LM descent stage (1969-018D) orbit decayed March 22, 1969. The remaining four days included more orbital maneuvers and a landmark tracking exercise. All systems on all spacecraft worked nearly normally during the mission, and all primary objectives were accomplished.

Apollo 9 splashed down in the Atlantic Ocean on March 13, 1969 after a mission elapsed time of 241 hrs, 0 mins, 54 sec. The splashdown point was 23° 15 min N, 67° 56 min W, 180 miles east of Bahamas and within sight of the recovery ship U.S.S. Guadalcanal. The Apollo 9 Command Module "Gumdrop" is on display at the Michigan Space and Science Center, Jackson, Michigan.

This spacecraft was the second Apollo mission to orbit the moon, and the first to travel to the moon with the full Apollo spacecraft, consisting of the Command and Service Module (CSM-106, "Charlie Brown") and the Lunar Module (LM-4, "Snoopy"). The LM mass including propellants was 13,941 kg. The primary objectives of the mission were to demonstrate crew, space vehicle, and mission support facilities during a manned lunar mission and to evaluate LM performance in cis-lunar and lunar environment. The mission was a full "dry run" for the Apollo 11 mission, in which all operations except the actual lunar landing were performed.

After launch, the spacecraft was inserted into a 189.9x184.4 km Earth parking orbit at 17:00:54 UT, followed by translunar injection after 1 1/2 orbits at 19:28:21 UT. The CSM separated from the Saturn V 3rd stage (S-IVB) at 19:51:42 UT, transposed, and docked with the LM at 20:06:37. After a three day cruise, Apollo 10 entered an initial 315.5x110.4 km lunar orbit on May 21, 1969 at 20:44:54 UT, using a 356 sec. SPS burn. A second SPS burn lasting 19.3 seconds circularized the orbit to 113.9x109.1 km.

On May 22, Stafford and Cernan entered the LM and fired the SM reaction control thrusters to separate the LM from the CSM at 19:36:17 UT. The LM was put into an orbit to allow low altitude passes over the lunar surface, the closest approach bringing it to within 14 km of the moon. All systems on the LM were tested during the separation including communications, propulsion, attitude control, and radar. Numerous close-up photographs of the Moon's surface, in particular the planned Apollo landing sites, were taken. The LM descent stage was jettisoned into lunar orbit. The LM and CSM rendezvous and re-docking occurred 8 hours after separation at 03:22 UT on May 23.

Later on May 23, the LM ascent stage was jettisoned into solar orbit, and on May 24 at 10:25:29 UT after 31 lunar orbits the CSM rockets fired for trans-earth injection. CM-SM separation took place on May 26, at 16:22:26 UT and Apollo 10 splashed down in the Pacific Ocean on 26 May 1969, after a mission elapsed time of 192 hrs, 3 mins, 23 sec. The splashdown point was 15° 2 min S, 164° 39 min W, 400 miles East of American Samoa and 5.5 km (3.4 mi) from the recovery ship U.S.S. Princeton.

All systems on both spacecraft functioned nominally, the only exception being an anomaly in the automatic abort guidance system aboard the LM. In addition to extensive photography of the lunar surface from both the LM and CSM, television images were taken and transmitted to Earth. The Apollo 10 Command Module "Charlie Brown" is on display at the Science Museum, London, England.

Apollo 11 was the first mission in which humans walked on the lunar surface and returned to Earth. On July 20, 1969 two astronauts (Apollo 11 Commander Neil A. Armstrong and LM pilot Edwin E. "Buzz" Aldrin Jr.) landed in Mare Tranquillitatis (the Sea of Tranquility) on the Moon in the Lunar Module (LM) while the Command and Service Module (CSM) (with CM pilot Michael Collins) continued in lunar orbit. During their stay on the moon, the astronauts set up scientific experiments, took photographs, and collected lunar samples. The LM took off from the Moon on July 21 and the astronauts returned to Earth on July 24.

After launch on Saturn V SA-504 on July 16, 1969 from pad 39A of Kennedy Space Center, Apollo 11 entered Earth orbit. After 1 1/2 Earth orbits, the S-IVB stage was re-ignited at 16:16:16 UT for a translunar injection burn of 5 minutes, 48 seconds putting the spacecraft on course for the moon. The CSM separated from the S-IVB stage containing the LM33 minutes later, turned around and docked with the LM at 16:56:03 UT. About an hour and 15 minutes later the S-IVB stage was injected into heliocentric orbit. During translunar coast a color TV transmission was made from Apollo 11 and on July 17 a 3-second mid-course correction burn of the main engine was performed. Lunar orbit insertion was achieved on July 19 at 17:21:50 UT by a retrograde firing of the main engine for 357.5 seconds while the spacecraft was behind the moon and out of contact with Earth. A later 17 second burn circularized the orbit. On July 20 Armstrong and Aldrin entered the LM for final checkout. At 18:11:53 the LM and CSM separated. After a visual inspection by Collins, the LM descent engine fired for 30 seconds at 19:08 UT, putting the craft into a descent orbit with a closest approach 14.5 km above the moon's surface. At 20:05 the LM descent engine fired for 756.3 seconds and descent to the lunar surface began.

The LM landed at 20:17:40 UT (4:17:40 p.m. EDT) in Mare Tranquillitatis (the Sea of Tranquility), Armstrong reporting, "Houston, Tranquility Base here - the Eagle has landed." Armstrong stepped onto the lunar surface at 02:56:15 UT on July 21 stating, "That's one small step for man, one giant leap for mankind", and Aldrin followed 19 minutes later. The astronauts deployed the EASEP and other instruments, took photographs, and collected 21.7 kg of lunar rock and soil. The astronauts traversed a total distance of about 250 meters. The EVA ended at 5:11:13 UT when the astronauts returned to the LM and closed the hatch.

The LM lifted off from the Moon at 17:54:01 UT on July 21 after 21 hours, 36 minutes on the lunar surface. After docking with the CSM at 21:34:00 UT, the LM was jettisoned into lunar orbit at 00:01:01 UT on July 22. Trans-Earth injection began at 04:54:42 UT on July 22 with a 2 1/2 minute firing of the CSM main engine. A mid-course correction was made later on 22 July. The CM separated from the SM at 16:21:13 UT on July 24. Apollo 11 splashed down in the Pacific Ocean on July 24, 1969 after a mission elapsed time of 195 hrs, 18 mins, 35 sec. The splashdown point was 13° 19 min N, 169° 9 min W, 400 miles SSW of Wake Island and 24 km (15 mi) from the recovery ship U.S.S. Hornet.

The performance of the spacecraft was excellent throughout the mission. The primary mission goal of landing astronauts on the moon and returning them to Earth was achieved. Armstrong was a civilian on his second spaceflight (he'd previously flown on Gemini 8), Aldrin was a USAF Colonel on his second spaceflight (Gemini 12), Collins was a USAF Lt. Colonel also on his second flight (Gemini 10). The backup crew for this mission was Jim Lovell, Fred Haise, and William Anders. The Apollo 11 Command Module is on display at the National Air and Space Museum in Washington, D.C.

Apollo 12 was the second mission in which humans walked on the lunar surface and returned to Earth. On November 19, 1969, two astronauts (Apollo 12 Commander Charles P. "Pete" Conrad and LM Pilot Alan L. Bean) landed in Oceanus Procellarum (Ocean of Storms) on the moon in the Lunar Module (LM) while the Command and Service Module (CSM) (with CM pilot Richard F. Gordon) continued in lunar orbit. During their stay on the moon, the astronauts set up scientific experiments, took photographs, examined the nearby Surveyor 3 spacecraft which had landed on the Moon 2 1/2 years earlier and removed pieces for later examination on Earth, and collected lunar samples on two moonwalk EVA's. The LM took off from the moon on 20 November and the astronauts returned to Earth on November 24.

Launch took place under cloudy, rain-swept skies on Saturn V SA-507 on November 14, 1969 from Pad 39A at Kennedy Space Center. The spacecraft was struck by lightning 36 seconds after launch and again 52 seconds after launch, which momentarily shut off electrical power and cut out telemetry contact. Power was automatically switched to battery backup while the crew restored the primary power system. There were no further problems with the power system and the spacecraft entered planned Earth parking orbit at 11 minutes 44 seconds after liftoff. After 1 1/2 orbits the S-IVB stage was re-ignited at 19:15:14 UT for a translunar injection burn of 5 min 45 sec putting the spacecraft on course for the moon.

The CSM separated from the S-IVB stage containing the LM25 minutes later, turned around and docked with the LM at 19:48:53 UT. The S-IVB stage was then jettisoned into Earth orbit instead of planned heliocentric orbit due to error in the instrument unit. During lunar coast, the LM was checked out to ensure no electrical damage had been caused by the lightning. A midcourse correction was made on November 16 at 02:15 UT. A six minute SPS burn on November 18 at 03:47:23 UT put the Apollo 12 into lunar orbit. Two orbits later a second burn circularized the orbit. Conrad and Bean entered the LM and it separated from the CSM at 04:16:03 UT on November 19. The LM descent engine fired for 29 seconds at 05:47 UT, and the LM landed in Oceanus Procellarum near the rim of Surveyor crater at 06:54:35 UT. Conrad and Bean performed two surface EVA's, one on November 19 and one on November 20, during which an Apollo lunar surface experiments package (ALSEP) was placed on the lunar surface, 34.4 kg of samples of the lunar terrain were acquired, various photographs were exposed by the astronauts during lunar surface activities, and parts were taken from the Surveyor 3 spacecraft for examination.

The LM lifted off from the Moon on November 20 at 14:25:47 UT after 31 hours 31 minutes on the lunar surface. After docking with the CSM at 17:58:22 UT, the LM was jettisoned at 20:21:30 and intentionally crashed into the moon creating the first recorded artificial moonquake. Trans-Earth injection began at 20:49:16 UT on November 21 with a firing of the CSM main engine. A mid-course correction was made on November 22. The CM separated from the SM on November 24 at 20:29:21. Apollo 12 splashed down in the Pacific Ocean on November 24, 1969 after a mission elapsed time of 244 hrs, 36 mins, 24 sec. The splashdown point was 15° 47 min S, 165° 9 min W, near American Samoa and 6.9 km (4.3 mi) from the recovery ship U.S.S. Hornet.

Performance of the spacecraft, the first of the Apollo H-series missions, was very good for all aspects of the mission. The primary mission goals of an extensive series of lunar exploration tasks, deployment of the ALSEP, and demonstration of the ability to remain and work on the surface of the moon for an extended period were achieved. Conrad was a Navy Commander on his third spaceflight (previously on Gemini's 5 and 11, later to fly on Skylab 2), Bean was a Navy Lt. Commander on his first flight (he later flew on Skylab 3), and Gordon was a Navy Commander on his second flight (Gemini 11). The backup crew for this mission was David Scott, Alfred Worden, and James Irwin. The Apollo 12 Command Module "Yankee Clipper" is on display at the Virginia Air and Space Center in Hampton, Virginia. The returned Surveyor 3 camera is on display at the Smithsonian Air and Space Museum in Washington, D.C.

Apollo 13 was intended to be the third mission to carry humans to the surface of the moon, but an explosion of one of the oxygen tanks and resulting damage to other systems resulted in the mission being aborted before the planned lunar landing could take place. The crew were returned safely to Earth on April 17, 1970.

Apollo 13 was launched on Saturn V SA-508 on April 11, 1970 from pad 39A at Kennedy Space Center. During second stage boost the center engine of the S-II stage cut off 132 seconds early, causing the remaining four engines to burn 34 seconds longer than normal. The velocity after S-II burn was still lower than planned by 68 m/sec, so the S-IVB orbital insertion burn at 19:25:40 was 9 seconds longer than planned. Translunar injection took place at 21:54:47 UT, CSM/S-IVB separation at 22:19:39 UT, and CSM-LM docking at 22:32:09 UT. The S-IVB auxiliary propulsive system burned at 01:13 UT on April 12 for 217 seconds to put the S-IVB into a lunar impact trajectory. (It impacted the lunar surface on April 14 at 01:09:41.0 at 2.75 S, 27.86 W with a velocity of 2.58 km/s at a 76° angle from horizontal.) A 3.4 second mid-course correction was made at 01:27 UT on April 13.

A television broadcast was made from Apollo 13 from 02:24 UT to 02:59 UT on April 14 and a few minutes later, at 03:06:18 UT Jack Swigert turned the fans on to stir oxygen tanks 1 and 2 in the service module. The Accident Review Board concluded that wires which had been damaged during pre-flight testing in oxygen tank no. 2 shorted and the teflon insulation caught fire. The fire spread within the tank, raising the pressure until at 3:07:53 UT on April 14 (55:54:53 mission elapsed time) oxygen tank no. 2 exploded, damaging oxygen tank no. 1 and the interior of the service module and blowing off the bay no. 4 cover. With the oxygen stores depleted, the command module was unusable, the mission had to be aborted, and the crew transferred to the lunar module and powered down the command module.

At 08:43 UT a mid-course maneuver (11.6 m/s delta V) was performed using the lunar module descent propulsion system (LMDPS) to place the spacecraft on a free-return trajectory which would take it around the moon and return to Earth, targeted at the Indian Ocean at 03:13 UT April 18. After rounding the moon another LMDPS burn at 02:40:39 UT April 15 for 263.4 seconds produced a differential velocity of 262 m/s and shortened the estimated return time to 18:06 UT April 17 with splashdown in the mid-Pacific. To conserve power and other consumables the lunar module was powered down except for environmental control, communications, and telemetry, and passive thermal control was established. At 04:32 UT on April 16 a 15 second LMDPS burn at 10% throttle produced a 2.3 m/s velocity decrease and raised the entry flight path angle to -6.52°. Following this the crew partially powered up the CSM. On April 17 at 12:53 UT a 22.4 second LMDPS burn put the flight path entry angle at -6.49°.

The service module, which had been kept attached to the command module to protect the heat shield, was jettisoned on April 17 at 13:15:06 UT and the crew took photographs of the damage. The command module was powered up and lunar module was jettisoned at 16:43:02 UT. Any parts of the lunar module which survived atmospheric re-entry, including the SNAP-27 generator, planned to power the ALSEP apparatus on the lunar surface and containing 3.9 kg of plutonium, fell into the Pacific Ocean northeast of New Zealand. Apollo 13 splashed down in the Pacific Ocean on April 17, 1970 after a mission elapsed time of 142 hrs, 54 mins, 41 sec. The splashdown point was 21° 38 min S, 165° 22 min W, SE of American Samoa and 6.5 km (4 mi) from the recovery ship U.S.S. Iwo Jima.

The spacecraft was the second of the Apollo H-series. The purposes of the mission were:

These goals were to be carried out from a near-circular lunar orbit and on the lunar surface at 3° S latitude, 17° W longitude. Although the planned mission objectives were not realized, a limited amount of photographic data was obtained. Lovell was a Navy captain on his fourth spaceflight (he'd flown previously on Gemini 7, Gemini 12, and Apollo 8), Haise and Swigert were both civilians on their first spaceflights. The backup crew was John Young, Charles Duke, and John Swigert (who replaced Thomas Mattingly on the prime crew after the crew was exposed to German measles). The Apollo 13 Command Module "Odyssey" is now at the Kansas Cosmosphere and Space Center, Hutchinson, Kansas. It was originally on display at the Musee de l'Air, Paris, France.

Apollo 14 was the third mission in which humans walked on the lunar surface and returned to Earth. During their stay on the moon, the astronauts set up scientific experiments, took photographs, and collected lunar samples. The LM took off from the moon on February 6 and the astronauts returned to Earth on February 9.

After a delay of 40 minutes, 2 seconds due to clouds and rain, Apollo 14 was launched into Earth parking orbit on January 31, 1971 at 21:03:02 UT from pad 39A of Kennedy Space Center on Saturn V SA-509. Earth orbit insertion occurred at 21:14:51 UT followed by translunar injection at 23:37:34. An early first mid-course correction was made to make up for the launch delay so the spacecraft would arrive at the moon on schedule. The CSM separated from the S-IVB stage containing the LM at 00:05:31 UT on February 1. Five attempts were made to dock the CSM and the LM, all unsuccessful because the catches on the docking ring did not release. The sixth attempt, at 02:00:02 UT, was successful and no further problems with the docking mechanism occurred. The S-IVB stage was released into a lunar impact trajectory. (It impacted the lunar surface on February 4 at 07:40:55.4 UT at 8.09 S, 26.02 W with a velocity of 2.54 km/s at a 69° angle from the horizontal.) A second mid-course correction was made on February 2 and a third on February 4. Lunar orbit insertion occurred at 06:59:43 UT on February 4.

The LM, with Shepard and Mitchell aboard, separated from the CSM, piloted by Roosa, at 04:50:44 UT on February 5 and landed at 09:18:11 UT in the hilly upland region 24 km north of the rim of Fra Mauro crater at 3.6 S, 17.5 W. The astronauts made two moonwalk EVA's totaling 9 hours, 23 minutes, one on February 5 and one on February 6, during which the Apollo lunar surface experiments package (ALSEP) was placed on the surface of the moon, 42.9 kg of lunar samples were acquired, and photographs were taken. At the end of the second EVA Shepard hit two golf balls. Experiments were also performed from the CSM in equatorial orbit.

The LM lifted off from the moon at 18:48:42 UT on February 6 after 33 hours, 31 minutes on the lunar surface. After the LM docked with the CSM at 20:35:53 UT the lunar samples and other equipment were transferred from the LM and the LM was jettisoned at 22:48:00 UT. It impacted the moon on February 8 00:45:25.7 UT at 3.42 S, 19.67 W. Trans-Earth injection began at 01:39:04 UT on February 7. One small mid-course correction was made on February 8. The CM separated from the SM at 20:35:44 UT on February 9. Apollo 14 splashed down in the Pacific Ocean on February 9, 1971 at 21:05:00 UT after a mission elapsed time of 216 hrs, 1 min, 58 sec. The splashdown point was 27° 1 min S, 172° 39 min W, 765 nautical miles south of American Samoa. The astronauts and capsule were picked up by the recovery ship U.S.S. New Orleans. This was the last Apollo mission in which the astronauts were put in quarantine after their return.

Performance of the spacecraft, the third of the Apollo H-series missions, was good for most aspects of the mission. The primary mission goals of deployment of the ALSEP and other scientific experiments, collection of lunar samples, surface photography, and photography, radio science and other scientific experiments from orbit were achieved with the exception of the full coverage planned for the Hycon camera. Shepard, 47, was a Navy captain on his second spaceflight (he'd flown previously as the first American in space on Mercury Redstone 3), Roosa, 37, was an Air Force major on his first spaceflight, and Mitchell, 40, was a Navy commander also on his first spaceflight. The backup crew for this mission was Eugene Cernan, Ronald Evans, and Joe Engle. The Apollo 14 command module "Kitty Hawk" is currently on display at the Astronaut Hall of Fame in Titusville, Florida.

Apollo 15 was the fourth mission in which humans walked on the lunar surface and returned to Earth. During their stay on the moon, the astronauts set up scientific experiments, took photographs, and collected lunar samples. The LM took off from the Moon on August 2 and the astronauts returned to Earth on August 7.

Apollo 15 launched on July 26, 1971 at 13:34:00 UT on Saturn V SA-510 from Pad 39A at Kennedy Space Center. The spacecraft was inserted into Earth orbit at 13:45:44 UT and translunar injection took place at 16:30:03 UT. The CSM separated from the S-IVB stage at 16:56:24 UT and docked with the LM at 17:07:49 UT. The S-IVB stage was released and burns at 19:22 UT and 23:34 UT sent the stage into a lunar impact trajectory. (It impacted the lunar surface on July 29 at 20:58:42.9 UT at 1.51 S, 11.81 W with a velocity of 2.58 km/s at a 62° angle from the horizontal.) A short was discovered in the service propulsion system and contingency procedures were developed for using the engine. A mid-course correction was performed on July 27 at 18:14:22 UT and another on July 29 at 15:05:15. During cruise it was discovered that the LM range/range-rate exterior glass cover had broken and a small water leak had developed in the CM requiring repair and clean-up. The SIM door was jettisoned at 15:40 UT and lunar orbit insertion took place at 20:05:47 UT. The descent orbit maneuver was executed at 00:13:49 UT on July 30.

Scott and Irwin entered the LM and the LM-CSM undocking maneuver was initiated at 17:48 UT but undocking did not take place. Worden found a loose umbilical plug and reconnected it, allowing the LM to separate from the CSM at 18:13:30 UT. The LM fired its descent engine at 22:04:09 UT and landed at 22:16:29 UT on July 30 1971 in the Mare Imbrium region at the foot of the Apennine mountain range at 26.1 N, 3.6 E. Scott and Irwin made three moonwalk EVAs totaling 18 hours, 35 minutes. During this time they covered 27.9 km, collected 76.8 kg of rock and soil samples, took photographs, and set up the ALSEP and performed other scientific experiments. This was the first mission which employed the Lunar Roving Vehicle which was used to explore regions within 5 km of the LM landing site. After the final EVA Scott performed a televised demonstration of a hammer and feather falling at the same rate in the lunar vacuum. The CSM remained in a slightly elliptical orbit from which Worden performed scientific experiments.

The LM lifted off from the Moon at 17:11:22 UT on August 2 after 66 hours, 55 minutes on the lunar surface. After the LM docked with the CSM at 19:09:47 UT the lunar samples and other equipment were transferred from the LM. The LM was jettisoned at 01:04:14 UT on August 3, after a one orbit delay to ensure LM and CSM hatches were completely sealed. The LM impacted the moon on August 3 03:03:37.0 UT at 26.36 N, 0.25 E, 93 km west of the Apollo 15 ALSEP site, with an estimated impact velocity of 1.7 km/s at an angle of ~3.2° from horizontal. Experiments were performed from orbit over the next day.

After Apollo 15 underwent an orbit-shaping maneuver the scientific subsatellite was spring-launched from the SM SIM bay at 20:13:19 UT on August 4 into a 102.0x141.3 km lunar orbit. Trans-Earth injection began on the next orbit with a 2 minute, 21 second main engine burn at 21:22:45 UT. On August 5, Worden carried out the first deep space EVA when he exited the CM and made three trips to the SIM bay at the rear of the SM to retrieve film canisters and check the equipment. Total EVA time was 38 minutes, 12 seconds. The CM separated from the SM at 20:18:00 UT on August 7. During descent, one of the three main parachutes failed to open fully, resulting in a descent velocity of 35 km/hr (21.8 mph), 4.5 km/hr (2.8 mph) faster than planned. Apollo 15 splashed down in the Pacific Ocean on August 7, 1971 at 20:45:53 UT after a mission elapsed time of 295 hrs, 11 mins, 53 sec. The splashdown point was 26° 7 min N, 158° 8 min W, 330 miles north of Honolulu, Hawaii and 9.8 km (6.1 mi) from the recovery ship U.S.S. Okinawa.

Performance of the spacecraft, the first of the Apollo J-series missions, was excellent for most aspects of the mission. The primary mission goals of exploration of the Hadley-Appenine region, deployment of the ALSEP and other scientific experiments, collection of lunar samples, surface photography, and photography and other scientific experiments from orbit, and engineering evaluation of new Apollo equipment, particularly the rover, were achieved. Scott, 39, was an Air Force Colonel on his third spaceflight (he'd flown previously on Gemini 8 and Apollo 9), Worden, 39, was an Air Force major on his first spaceflight, and Irwin, 41, was an Air Force lt. colonel also on his first spaceflight. The backup crew for this mission was Richard Gordon, Vance Brand, and Harrison Schmitt. The Apollo 15 command module "Endeavor" is on display at the USAF Museum at Wright-Patterson Air Force Base, Dayton, Ohio.

Apollo 16 was the fifth mission in which humans walked on the lunar surface and returned to Earth. During their stay on the moon, the astronauts set up scientific experiments, took photographs, and collected lunar samples. The LM took off from the Moon on April 24 and the astronauts returned to Earth on April 27.

Apollo 16 launched on April 16, 1972 at 17:54:00 on Saturn V SA-511 from Pad 39A at Kennedy Space Center. (The launch was postponed from the originally scheduled date, March 17, because of a docking ring jettison malfunction.) The spacecraft entered Earth parking orbit at 18:05:56 UT and translunar injection took place at 20:27:37 UT. The CSM and S-IVB stage separated at 20:58:59 UT and CSM-LM docking was achieved at 21:15:53 UT. The S-IVB stage was released into a lunar impact trajectory, but due to an earlier problem with the auxiliary propulsion system (APS) helium regulators, which resulted in continuous venting and loss of helium, the second APS burn could not be made. Tracking of the S-IVB was lost on April 17 at 21:03 UT due to a transponder failure. (The S-IVB stage impacted the moon on April 19 at 21:02:04 UT at 1.3 N, 23.8 W with a velocity of 2.5 to 2.6 km/s at a 79° angle from the horizontal, as estimated from the Apollo 12, 14 and 16 seismic station data.) A mid-course correction was performed at 00:33:01 UT on April 18. During translunar coast a CSM navigation problem was discovered in which a false indication would cause loss of inertial reference, this was solved by a real-time change in the computer program. The SIM door was jettisoned on April 19 at 15:57:00 UT and lunar orbit insertion took place at 20:22:28 UT. Two revolutions later the orbit was lowered to one with a perilune of 20 km.

At 15:24 UT on April 20 Young and Duke entered the LM. The LM separated from the CSM at 18:08:00 UT, but the LM descent was delayed almost 6 hours due to a malfunction in the yaw gimbal servo loop on the CSM which caused oscillations in the service propulsion system (SPS). Engineers determined that the problem would not seriously affect CSM steering and the mission was allowed to continue with the LM descent. The LM landed at 02:23:35 UT on April 21 in the Descartes highland region just north of the crater Dolland at 9.0 S, 15.5 E. Young and Duke made three moonwalk EVAs totaling 20 hours, 14 minutes. During this time they covered 27 km using the Lunar Roving Vehicle, collected 94.7 kg of rock and soil samples, took photographs, and set up the ALSEP and other scientific experiments. Other experiments were also performed from orbit in the CSM during this time.

The LM lifted off from the moon at 01:25:48 UT on April 24 after 71 hours, 2 minutes on the lunar surface. After the LM docked with the CSM at 03:35:18 UT the lunar samples and other equipment were transferred from the LM and the LM was jettisoned at 20:54:12 UT on April 24. The LM began tumbling, apparently due to an open circuit breaker in the guidance and navigation system. As a result the planned deorbit and lunar impact could not be attempted. The LM remained in lunar orbit with an estimated lifetime of one year. The instrument boom which carried the orbital mass spectrometer would not retract and was jettisoned. Because of earlier problems with the SPS yaw gimbal servo loop the mission was shortened by one day. The orbital shaping maneuver was cancelled, and the subsatellite was spring-launched at 21:56:09 UT into an elliptical orbit with a lifetime of one month, rather than the planned one-year orbit. Trans-Earth injection began at 02:15:33 UT on April 25. On April 25 at 20:43 UT, Mattingly began a cis-lunar EVA to retrieve camera film from the SIM bay and inspect instruments, two trips taking a total of 1 hour, 24 minutes. The CM separated from the SM on April 27 at 19:16:33 UT. Apollo 16 splashed down in the Pacific Ocean on April 27, 1972 at 19:45:05 UT after a mission elapsed time of 265 hrs, 51 mins, 5 sec. The splashdown point was 0° 43 min S, 156° 13 min W, 215 miles southeast of Christmas Island and 5 km (3 miles) from the recovery ship U.S.S. Ticonderoga.

Performance of the spacecraft, the second of the Apollo J-series missions, was good for most aspects of the mission. The primary mission goals of inspecting, surveying, and sampling materials in the Descartes region, emplacement and activation of surface experiments, conducting in-flight experiments and photographic tasks from lunar orbit, engineering evaluation of spacecraft and equipment, and performance of zero-gravity experiments were achieved despite the mission being shortened by one day. Young, 41, was a Navy Captain who had flown on three previous spaceflights (Gemini 3, Gemini 10, and Apollo 10; he later flew on STS-1 and STS-9), Mattingly, 36, was a Navy lt. commander on his first spaceflight (he later flew STS-4 and STS-51C), and Duke, 36, was an Air Force lt. colonel also on his first spaceflight. The backup crew for this mission was Fred Haise, Stuart Roosa, and Edger Mitchell. The Apollo 16 Command Module "Casper" is on display at the Alabama Space and Rocket Center in Huntsville, Alabama.

Apollo 17 was the sixth and last Apollo mission in which humans walked on the lunar surface. During their stay on the moon, the astronauts set up scientific experiments, took photographs, and collected lunar samples. The LM took off from the Moon on December 14 and the astronauts returned to Earth on 1December 9.

Apollo 17 lifted off at 05:33:00 UT on December 7, 1972 after a 2 hour, 40 minute delay due to a malfunction of a launch sequencer. Launch was on Saturn V SA-512 from Pad 39A at Kennedy Space Center and was the first nighttime launch of an Apollo. The spacecraft began Earth parking orbit at 05:44:53 UT and translunar injection took place at 08:45:37 UT. The CSM separated from the S-IVB at 09:15:29 UT and CSM-LM docking took place at 09:29:45 UT. The S-IVB was released at 10:18 UT into a lunar impact trajectory. (It impacted the lunar surface on December 10 at 20:32:42.3 UT at 4.21 S, 12.31 W with a velocity of 2.55 km/s at a 55° angle from the horizontal.) A single mid-course correction requiring a 1.6 second burn of the Service Propulsion System (SPS) was made at 17:03:00 UT on December 8. On December 10 at 15:05:40 UT the SIM bay door was jettisoned and a 398 second burn of the SPS was initiated at 19:47:23 UT to insert Apollo 17 into lunar orbit. Approximately 4 hours 20 minutes later another maneuver lowered the orbit to a perilune of 28 km. At 14:35 UT on December 11 Cernan and Schmitt entered the LM.

The LM separated from the CSM at 17:20:56 UT on December 11 and reduced its orbit to 11.5 km perilune at 18:55:42 UT. The descent burn took place at 19:43 UT and the LM landed at 19:54:57 UT on the southeastern rim of Mare Serenitatis in a valley at Taurus-Littrow, at 20.2 N, 30.8 E. Cernan and Schmitt made three moonwalk extra-vehicular activities (EVAs) totaling 22 hours, 4 minutes. During this time they covered 30 km using the Lunar Roving Vehicle, collected 110.5 kg of lunar samples, took photographs, and set up the ALSEP and performed other scientific experiments. Evans performed experiments from orbit in the CSM during this time.

The LM lifted off from the moon at 22:54:37 UT on December 14 after 75 hours on the lunar surface. After the LM docked with the CSM at 01:10:15 UT on December 15 the lunar samples and other equipment were transferred from the LM and the LM was jettisoned at 04:51:31 UT. The LM impacted the moon at 06:50:20.8 UT at 19.96 N, 30.50 E, approximately 15 km from the Apollo 17 landing site, with an estimated impact velocity of 1.67 km/s at an angle ~4.9° from horizontal. After another 1 1/2 days in lunar orbit, trans-Earth injection took place at 23:35:09 UT on December 16. On December 17 at 20:27 UT Evans began a cis-lunar spacewalk EVA consisting of three trips to the SM SIM bay to collect camera and lunar sounder film over a period of 67 minutes. The CM and SM separated at 18:56:49 UT on December 19. Apollo 17 splashed down in the Pacific Ocean on December 19, 1972 at 19:24:59 UT after a mission elapsed time of 301 hrs, 51 mins, 59 sec. The splashdown point was 17° 53 min S, 166° 7 min W, 350 nautical miles SE of the Samoan Islands and 6.5 km (4 miles) from the recovery ship U.S.S. Ticonderoga.

Performance of the spacecraft, the third of the Apollo J-series missions, was excellent for all aspects of the mission. The primary mission goals of investigating the lunar surface and environment in the Taurus-Littrow region, replacing and activating surface experiments, performing experiments in lunar orbit, obtaining and returning lunar surface samples, and enhancing the capability for future astronaut lunar exploration were achieved. Cernan, 38, was a Navy captain with two previous spaceflights (Gemini 9, Apollo 10), Evans, 39, was a Navy commander making his first spaceflight, and Schmitt, 37, was a civilian also making his first spaceflight. The backup crew for this mission was John Young, Stuart Roosa, and Charles Duke. The Apollo 17 command module capsule "America" is on display at the Johnson Space Center in Houston, Texas.