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Pad 505 Assignment 3 Presenting The Budget Cinema

John Young on the Moon, with the Lunar Module and Lunar Rover in the background

Mission typeManned lunar landing
  • CSM: 1972-031A
  • LM: 1972-031C
Mission duration11 d 1 h 51 min 5 s
Spacecraft properties
Launch mass107,226 pounds (48,637 kg)
Landing mass11,995 pounds (5,441 kg)
Crew size3
EVAs1 in cislunar space to retrieve film cassettes
EVA duration1 h 23 min 42 s
Start of mission
Launch dateApril 16, 1972, 17:54:00 (1972-04-16UTC17:54Z) UTC
RocketSaturn V SA-511
Launch siteKennedyLC-39A
End of mission
Recovered byUSS Ticonderoga
Landing dateApril 27, 1972, 19:45:05 (1972-04-27UTC19:45:06Z) UTC
Landing siteSouth Pacific Ocean
0°43′S156°13′W / 0.717°S 156.217°W / -0.717; -156.217 (Apollo 16 splashdown)
Orbital parameters
Reference systemSelenocentric
Periselene20.2 kilometers (10.9 nmi)
Aposelene108.3 kilometers (58.5 nmi)
EpochApril 20, 1972, 00:27 UTC
Lunar orbiter
Spacecraft componentCommand/Service Module
Orbital insertionApril 19, 1972, 20:22:27 UTC
Orbital departureApril 25, 1972, 02:15:33 UTC
Lunar lander
Spacecraft componentLunar Module
Landing dateApril 21, 1972, 02:23:35 UTC
Return launchApril 24, 1972, 01:25:47 UTC
Landing siteDescartes Highlands
8°58′23″S15°30′01″E / 8.97301°S 15.50019°E / -8.97301; 15.50019
Sample mass95.71 kilograms (211.0 lb)
Surface EVAs3
EVA duration
  • 20 h 14 min 14 s
  • First: 7 h 11 min 2 s
  • Second: 7 h 23 min 09 s
  • Third: 5 h 40 min 3 s
Lunar rover
Distance covered26.7 kilometers (16.6 mi)
Docking with LM
Docking dateApril 16, 1972, 21:15:53 UTC
Undocking dateApril 20, 1972, 18:07:31 UTC
Docking with LM Ascent Stage
Docking dateApril 24, 1972, 03:35:18 UTC
Undocking dateApril 24, 1972, 20:54:12 UTC
  • SIM:
  • LRV: 463 pounds (210 kg)

Left to right: Mattingly, Young, Duke

Apollo program

Apollo 16 was the tenth manned mission in the United States Apollo space program, the fifth and penultimate to land on the Moon and the first to land in the lunar highlands. The second of the so-called "J missions," it was crewed by Commander John Young, Lunar Module PilotCharles Duke and Command Module PilotKen Mattingly. Launched from the Kennedy Space Center in Florida at 12:54 PM EST on April 16, 1972, the mission lasted 11 days, 1 hour, and 51 minutes, and concluded at 2:45 PM EST on April 27.[2][3][4]

Young and Duke spent 71 hours—just under three days—on the lunar surface, during which they conducted three extra-vehicular activities or moonwalks, totaling 20 hours and 14 minutes. The pair drove the Lunar Roving Vehicle (LRV), the second produced and used on the Moon, 26.7 kilometers (16.6 mi). On the surface, Young and Duke collected 95.8 kilograms (211 lb) of lunar samples for return to Earth, while Command Module Pilot Ken Mattingly orbited in the Command/Service Module (CSM) above to perform observations. Mattingly spent 126 hours and 64 revolutions in lunar orbit. After Young and Duke rejoined Mattingly in lunar orbit, the crew released a subsatellite from the Service Module (SM). During the return trip to Earth, Mattingly performed a one-hour spacewalk to retrieve several film cassettes from the exterior of the Service Module.[2][3]

Apollo 16's landing spot in the highlands was chosen to allow the astronauts to gather geologically older lunar material than the samples obtained in the first four landings, which were in or near lunar maria. Samples from the Descartes Formation and the Cayley Formation disproved a hypothesis that the formations were volcanic in origin.[5]


Mattingly had originally been assigned to the prime crew of Apollo 13, but was exposed to the measles through Duke, at that time on the back-up crew for Apollo 13, who had caught it from one of his children. He never contracted the illness, but was nevertheless removed from the crew and replaced by his backup, Jack Swigert, three days before the launch.[7] Young, a captain in the United States Navy, had flown on three spaceflights prior to Apollo 16: Gemini 3, Gemini 10 and Apollo 10, which orbited the Moon.[8] One of 19 astronauts selected by NASA in April 1966, Duke had never flown in space before Apollo 16. He served on the support crew of Apollo 10 and was a Capsule Communicator (CAPCOM) for Apollo 11.[9]

Backup crew[edit]

Although not officially announced, the original backup crew consisted of Fred W. Haise (CDR), William R. Pogue (CMP) and Gerald P. Carr (LMP), who were targeted for the prime crew assignment on Apollo 19.[10][11] However, after the cancellations of Apollos 18 and 19 were finalized in September 1970 this crew would not rotate to a lunar mission as planned. Subsequently, Roosa and Mitchell were recycled to serve as members of the backup crew after returning from Apollo 14, while Pogue and Carr were reassigned to the Skylab program where they flew on Skylab 4.[12][13]

Support crew[edit]

Mission insignia[edit]

The insignia of Apollo 16 is dominated by a rendering of an American eagle and a red, white and blue shield, representing the people of the United States, over a gray background representing the lunar surface. Overlaying the shield is a gold NASA vector, orbiting the Moon. On its gold-outlined blue border, there are 16 stars, representing the mission number, and the names of the crew members: Young, Mattingly, Duke.[18] The insignia was designed from ideas originally submitted by the crew of the mission.[19]

Planning and training[edit]

Landing site selection[edit]

Apollo 16 was the second of the Apollo type J missions, featuring the use of the Lunar Roving Vehicle, increased scientific capability, and lunar surface stays of three days.[2] As Apollo 16 was the penultimate mission in the Apollo program and there was no new hardware or procedures to test on the lunar surface, the last two missions (the other being Apollo 17) presented opportunities for astronauts to clear up some uncertainties in understanding the Moon's properties. Although previous Apollo expeditions, including Apollo 14 and Apollo 15, obtained samples of pre-mare lunar material, before lava began to upwell from the Moon's interior and flood the low areas and basins, none had actually visited the lunar highlands.[20]

Apollo 14 had visited and sampled a ridge of material that had been ejected by the impact that created the Mare Imbrium impact basin. Likewise, Apollo 15 had also sampled material in the region of Imbrium, visiting the basin's edge. There remained the possibility, because the Apollo 14 and Apollo 15 landing sites were closely associated with the Imbrium basin, that different geologic processes were prevalent in areas of the lunar highlands far from Mare Imbrium. Several members of the scientific community remarked that the central lunar highlands resembled regions on Earth that were created by volcanic processes and hypothesized the same might be true on the Moon. They had hoped that scientific output from the Apollo 16 mission would provide an answer.[20]

Two locations on the Moon were given primary consideration for exploration by the Apollo 16 expedition: the Descartes Highlands region west of Mare Nectaris and the crater Alphonsus. At Descartes, the Cayley and Descartes formations were the primary areas of interest in that scientists suspected, based on telescopic and orbital imagery, that the terrain found there was formed by magma more viscous than that which formed the lunar maria. The Cayley Formation's age was approximated to be about the same as Mare Imbrium based on the local frequency of impact craters. The considerable distance between the Descartes site and previous Apollo landing sites would be beneficial for the network of geophysical instruments,[21] portions of which were deployed on each Apollo expedition beginning with Apollo 12.[5]

At the Alphonsus, three scientific objectives were determined to be of primary interest and paramount importance: the possibility of old, pre-Imbrium impact material from within the crater's wall, the composition of the crater's interior and the possibility of past volcanic activity on the floor of the crater at several smaller "dark halo" craters. Geologists feared, however, that samples obtained from the crater might have been contaminated by the Imbrium impact, thus preventing Apollo 16 from obtaining samples of pre-Imbrium material. There also remained the distinct possibility that this objective had already been satisfied by the Apollo 14 and Apollo 15 missions, as the Apollo 14 samples had not yet been completely analyzed and samples from Apollo 15 had not yet been obtained.[5]

It was decided to target the Apollo 16 mission for the Descartes site. Following the decision, the Alphonsus site was considered the most likely candidate for Apollo 17, but was eventually rejected. With the assistance of orbital photography obtained on the Apollo 14 mission, the Descartes site was determined to be safe enough for a manned landing. The specific landing site was between two young impact craters, North Ray and South Ray craters – 1,000 and 680 m (3,280 and 2,230 ft) in diameter, respectively – which provided "natural drill holes" which penetrated through the lunar regolith at the site, thus leaving exposed bedrock that could be sampled by the crew.[5]

After selecting the landing site for Apollo 16, sampling the Descartes and Cayley formations, two geologic units of the lunar highlands, was determined by mission planners to be the primary sampling interest of the mission. It was these formations that the scientific community widely suspected were formed by lunar volcanism, but this hypothesis was proven incorrect by the composition of lunar samples from the mission.[5]


In preparing for their mission, in addition to the usual Apollo spacecraft training, Young and Duke, along with backup commander Fred Haise, underwent an extensive geological training program that included several field trips to introduce them to concepts and techniques they would use in analyzing features and collecting samples on the lunar surface. During these trips, they visited and provided scientific descriptions of geologic features they were likely to encounter.[22][23][24] In July 1971, they visited Sudbury, Ontario, Canada for geology training exercises, the first time U.S. astronauts did so. Geologists chose the area because of a 60 mi (97 km) wide crater created about 1.8 billion years ago by a large meteorite.[25] The Sudbury Basin shows evidence of shatter cone geology familiarizing the Apollo crew with geologic evidence of a meteor impact. During the training exercises the astronauts did not wear space suits, but carried radio equipment to converse with each other and scientist-astronaut Anthony W. England, practicing procedures they would use on the lunar surface.[26]

In addition to the field geology training, Young and Duke also trained to use their EVA space suits, adapt to the reduced lunar gravity, collect samples, and drive the Lunar Roving Vehicle. They also received survival training and preparation for other technical aspects of the mission.[27]

Command Module pilot Mattingly also received training in recognizing geological features from orbit by flying over the field areas in an airplane, and trained to operate the Scientific Instrument Module from lunar orbit.

Mission highlights[edit]

Launch and outbound trip[edit]

The launch of Apollo 16 was delayed one month from March 17 to April 16. This was the first launch delay in the Apollo program due to a technical problem. During the delay, the space suits, a spacecraft separation mechanism and batteries in the Lunar Module (LM) were modified and tested.[28] There were concerns that the explosive mechanism designed to separate the docking ring from the Command Module (CM) would not create enough pressure to completely sever the ring. This, along with a dexterity issue in Young's space suit and fluctuations in the capacity of the Lunar Module batteries, required investigation and trouble-shooting.[29] In January 1972, three months before the planned April launch date, a fuel tank in the Command Module was accidentally damaged during a routine test.[30] The rocket was returned to the Vertical Assembly Building (VAB) and the fuel tank replaced, and the rocket returned to the launch pad in February in time for the scheduled launch.[31]

The official mission countdown began on Monday, April 10, 1972, at 8:30 AM, six days before the launch. At this point the Saturn V rocket's three stages were powered up and drinking water was pumped into the spacecraft. As the countdown began, the crew of Apollo 16 was participating in final training exercises in anticipation of a launch on April 16. The astronauts underwent their final preflight physical examination on April 11.[32] On April 15, liquid hydrogen and liquid oxygen propellants were pumped into the spacecraft, while the astronauts rested in anticipation of their launch the next day.[33]

The Apollo 16 mission launched from the Kennedy Space Center in Florida at 12:54 PM EST on April 16, 1972.[34] The launch was nominal; the crew experienced vibration similar to that of previous crews. The first and second stages of the Saturn V rocket performed nominally; the spacecraft entered orbit around Earth just under 12 minutes after lift-off. After reaching orbit, the crew spent time adapting to the zero-gravity environment and preparing the spacecraft for Trans Lunar Injection (TLI), the burn of the third-stage rocket that would propel them to the Moon. In Earth orbit, the crew faced minor technical issues, including a potential problem with the environmental control system and the S-IVB third stage's attitude control system, but eventually resolved or compensated for them as they prepared to depart towards the Moon. After two orbits, the rocket's third stage reignited for just over five minutes, propelling the craft towards the Moon at about 22,000 mph (35,000 km/h).[35] Six minutes after the burn of the S-IVB, the Command/Service Module, containing the crew, separated from the rocket and traveled for 15 m (49 ft) before turning around and retrieving the Lunar Module from inside the expended rocket stage. The maneuver, known as transposition, went smoothly and the LM was extracted from the S-IVB.[36][37] Following transposition and docking, the crew noticed the exterior surface of the Lunar Module was giving off particles from a spot where the LM's skin appeared torn or shredded; at one point, Duke estimated they were seeing about five to ten particles per second. The crew entered the Lunar Module through the docking tunnel connecting it with the Command Module to inspect its systems, at which time they did not spot any major issues. Once on course towards the Moon, the crew put the spacecraft into a rotisserie "barbecue" mode in which the craft rotated along its long axis three times per hour to ensure even heat distribution about the spacecraft from the Sun. After further preparing the craft for the voyage, the crew began the first sleep period of the mission just under 15 hours after launch.[38]

By the time Mission Control issued the wake-up call to the crew for flight day two, the spacecraft was about 98,000 nautical miles (181,000 km) away from the Earth, traveling at about 5,322 ft/s (1,622 m/s). As it was not due to arrive in lunar orbit until flight day four,[39] flight days two and three were largely preparatory days, consisting of spacecraft maintenance and scientific research. On day two, the crew performed an electrophoresis experiment, also performed on Apollo 14, in which they attempted to prove the higher purity of particle migrations in the zero-gravity environment. The remainder of day two included a two-second mid-course correction burn performed by the Command/Service Module's Service Propulsion System engine to tweak the spacecraft's trajectory. Later in the day, the astronauts entered the Lunar Module for the second time in the mission to further inspect the landing craft's systems. The crew reported they had observed additional paint peeling from a portion of the LM's outer aluminum skin. Despite this, the crew discovered that the spacecraft's systems were performing nominally. Following the LM inspection, the crew reviewed checklists and procedures for the following days in anticipation of their arrival and the Lunar Orbit Insertion burn. Command Module Pilot Mattingly reported a "gimbal lock" warning light, indicating the craft was not reporting an attitude. Mattingly alleviated this by realigning the guidance system using the Sun and Moon. At the end of day two, Apollo 16 was about 140,000 nautical miles (260,000 km) away from Earth.[40]

At the beginning of day three, the spacecraft was about 157,000 nautical miles (291,000 km) away from the Earth. The velocity of the craft steadily decreased, as it had not yet reached the lunar sphere of gravitational influence. The early part of day three was largely housekeeping, spacecraft maintenance and exchanging status reports with Mission Control in Houston. The crew performed the Apollo light flash experiment, or ALFMED, to investigate "light flashes" that were seen by the astronauts when the spacecraft was dark, regardless of whether or not their eyes were open, on Apollo lunar flights. This was thought to be caused by the penetration of the eye by cosmic ray particles.[41][42] During the second half of the day, Young and Duke again entered the Lunar Module to power it up and check its systems, and perform housekeeping tasks in preparation for lunar landing. The systems were found to be functioning as expected. Following this, the crew donned their space suits and rehearsed procedures that would be used on landing day. Just before the end of flight day three at 59 hours, 19 minutes, 45 seconds after liftoff, while 178,673 nautical miles (330,902 km) from the Earth and 33,821 nautical miles (62,636 km) from the Moon, the spacecraft's velocity began increasing as it accelerated towards the Moon after entering the lunar sphere of influence.[43]

After waking up on flight day four, the crew began preparations for the maneuver that would brake the spacecraft into orbit around the Moon, or lunar orbit insertion.[39] At a distance of 11,142 nautical miles (20,635 km) from the Moon, the Scientific Instrument Module (SIM) bay cover was jettisoned. At just over 74 hours into the mission, the spacecraft passed behind the Moon, losing direct contact with Mission Control. While over the far side of the Moon, the Command/Service Module's Service Propulsion System engine burned for 6 minutes and 15 seconds, braking the spacecraft into an orbit around the Moon with a low point (pericynthion) of 58.3 and a high point (apocynthion) of 170.4 nautical miles (108.0 and 315.6 km, respectively).[44] After entering lunar orbit, the crew began preparations for the Descent Orbit Insertion (DOI) maneuver to further modify the spacecraft's orbital trajectory. The maneuver was successful, decreasing the craft's pericynthion to 10.7 nautical miles (19.8 km). The remainder of flight day four was spent making observations and preparing for activation of the Lunar Module, undocking, and landing the next day.[45]

Lunar surface[edit]

The crew continued preparing for Lunar Module activation and undocking shortly after waking up to begin flight day five. The boom that extended the mass spectrometer out from the Command/Service Module's Scientific Instruments Bay was stuck in a semi-deployed position. It was decided that Young and Duke would visually inspect the boom after undocking from the CSM in the LM. They entered the LM for activation and checkout of the spacecraft's systems. Despite entering the LM 40 minutes ahead of schedule, they completed preparations only 10 minutes early due to numerous delays in the process.[37] With the preparations finished, they undocked in the LM Orion from Mattingly in the Command/Service Module Casper 96 hours, 13 minutes, 13 seconds into the mission.[46] For the rest of the two crafts' passes over the near side of the Moon, Mattingly prepared to shift Casper to a circular orbit while Young and Duke prepared Orion for the descent to the lunar surface. At this point, during tests of the CSM's steerable rocket engine in preparation for the burn to modify the craft's orbit, a malfunction occurred in the engine's backup system. According to mission rules, Orion would have then re-docked with Casper, in case Mission Control decided to abort the landing and use the Lunar Module's engines for the return trip to Earth. After several hours of analysis, however, mission controllers determined that the malfunction could be worked around and Young and Duke could proceed with the landing.[20] As a result of this, powered descent to the lunar surface began about six hours behind schedule. Because of the delay, Young and Duke began their descent to the surface at an altitude higher than that of any previous mission, at 20.1 kilometers (10.9 nmi). At an altitude of about 4,000 m (13,000 ft), Young was able to view the landing site in its entirety. Throttle-down of the LM's landing engine occurred on time and the spacecraft tilted forward to its landing orientation at an altitude of 2,200 m (7,200 ft). The LM landed 270 m (890 ft) north and 60 m (200 ft) west of the planned landing site at 104 hours, 29 minutes, and 35 seconds into the mission, at 2:23:35 UTC on April 21.[37][47]

After landing, Young and Duke began powering down some of the LM's systems to conserve battery power. Upon completing their initial adjustments, the pair configured Orion for their three-day stay on the lunar surface, removed their space suits and took initial geological observations of the immediate landing site. They then settled down for their first meal on the surface. After eating, they configured the cabin for their first sleep period on the Moon.[48][49] The landing delay caused by the malfunction in the Command/Service Module's main engine necessitated significant modifications to the mission schedule. Apollo 16 would spend one less day in lunar orbit after surface exploration had been completed to afford the crew contingency time to compensate for any further problems and to conserve expendables. In order to improve Young's and Duke's sleep schedule, the third and final moonwalk of the mission was trimmed from seven hours to five.[37]

The next morning, flight day five, Young and Duke ate breakfast and began preparations for the first extra-vehicular activity (EVA), or moonwalk.[50][51] After the pair donned and pressurized their space suits and depressurized the Lunar Module cabin, Young climbed out onto the "porch" of the LM, a small platform above the ladder. Duke handed Young a jettison bag full of trash to dispose of on the surface.[52] Young then lowered the equipment transfer bag (ETB), containing equipment for use during the EVA, to the surface. Young descended the ladder and, upon setting foot on the lunar surface, became the ninth human to walk on the Moon.[37] Upon stepping onto the surface, Young expressed his sentiments about being there: "There you are: Mysterious and Unknown Descartes. Highland plains. Apollo 16 is gonna change your image. I'm sure glad they got ol' Brer Rabbit, here, back in the briar patch where he belongs."[52] Duke soon descended the ladder and joined Young on the surface, becoming the tenth and youngest human to walk on the Moon, at age 36. After setting foot on the lunar surface, Duke expressed his excitement, commenting: "Fantastic! Oh, that first foot on the lunar surface is super, Tony!"[52] The pair's first task of the moonwalk was to unload the Lunar Roving Vehicle, the Far Ultraviolet Camera/Spectrograph (UVC),[53] and other equipment, from the Lunar Module. This was done without problems. On first driving the lunar rover, Young discovered that the rear steering was not working. He alerted Mission Control to the problem before setting up the television camera and planting the flag of the United States with Duke. The day's next task was to deploy the Apollo Lunar Surface Experiments Package (ALSEP); while they were parking the lunar rover, on which the TV camera was mounted, to observe the deployment, the rear steering began functioning without explanation. While deploying a heat-flow experiment (that had burned up with the Lunar Module Aquarius on Apollo 13 and had been attempted with limited success on Apollo 15), a cable was inadvertently snapped after getting caught around Young's foot. After ALSEP deployment, they collected samples in the vicinity. About four hours after the beginning of EVA-1, they mounted the lunar rover and drove to the first geologic stop, Plum Crater, a 36 m-wide (118 ft) crater on the rim of Flag crater, about 240 m (790 ft) across. There, at a distance of 1.4 km (0.87 mi) from the LM, they sampled material from the vicinity of Flag Crater, which scientists believed penetrated through the upper regolith layer to the underlying Cayley Formation. It was there that Duke retrieved, at the request of Mission Control, the largest rock returned by an Apollo mission, a breccia nicknamed Big Muley after mission geology principal investigator William R. Muehlberger.[54][55] The next stop of the day was Buster Crater, about 1.6 km (0.99 mi) from the LM. There, Duke took pictures of Stone Mountain and South Ray Crater while Young deployed a magnetic field experiment.[56] At that point, scientists began to reconsider their pre-mission hypothesis that Descartes had been the setting of ancient volcanic activity, as the two astronauts had yet to find any volcanic material. Following their stop at Buster, Young did a demonstration drive of the lunar rover while Duke filmed with a 16 mm movie camera.[57] After completing more tasks at the ALSEP, they returned to the LM to close out the moonwalk. They reentered the LM 7 hours, 6 minutes, and 56 seconds after the start of the EVA. Once inside, they pressurized the LM cabin, went through a half-hour briefing with scientists in Mission Control, and configured the cabin for the sleep period.[54][58][59]

Shortly after waking up on the morning of flight day six three and a half minutes early, they discussed with Mission Control in Houston the day's timeline of events.[60][61] The second lunar excursion's primary objective was to visit Stone Mountain to climb up the slope of about 20 degrees to reach a cluster of five craters known as "Cinco Craters." After preparations for the day's moonwalk were completed, the astronauts climbed out of the Lunar Module. After departing the immediate landing site in the lunar rover, they arrived at the day's first destination, the Cinco Craters, 3.8 km (2.4 mi) from the LM. At 152 m (499 ft) above the valley floor, the pair were at the highest elevation above the LM of any Apollo mission. After marveling at the view (including South Ray) from the side of Stone Mountain, which Duke described as "spectacular,"[62] the astronauts gathered samples in the vicinity.[54] After spending 54 minutes on the slope, they climbed aboard the lunar rover en route to the day's second stop, station five, a crater 20 m (66 ft) across. There, they hoped to find Descartes material that had not been contaminated by ejecta from South Ray Crater, a large crater south of the landing site. The samples they collected there, although their origin is still not certain, are, according to geologist Don Wilhelms, "a reasonable bet to be Descartes."[54] The next stop, station six, was a 10 m-wide (33 ft) blocky crater, where the astronauts believed they could sample the Cayley Formation as evidenced by the firmer soil found there. Bypassing station seven to save time, they arrived at station eight on the lower flank of Stone Mountain, where they sampled material on a ray from South Ray Crater for about an hour. There, they collected black and white breccias and smaller, crystalline rocks rich in plagioclase. At station nine, an area known as the "Vacant Lot,"[63] which was believed to be free of ejecta from South Ray, they spent about 40 minutes gathering samples. Twenty-five minutes after departing station nine, they arrived at the final stop of the day, halfway between the ALSEP site and the LM. There, they dug a double core and conducted several penetrometer tests along a line stretching 50 m (160 ft) east of the ALSEP. At the request of Young and Duke, the moonwalk was extended by ten minutes. After returning to the LM to wrap up the second lunar excursion, they climbed back inside the landing craft's cabin, sealing and pressurizing the interior after 7 hours, 23 minutes, and 26 seconds of EVA time, breaking a record that had been set on Apollo 15.[54][64] After eating a meal and proceeding with a debriefing on the day's activities with Mission Control, they reconfigured the LM cabin and prepared for the sleep period.[65]

Flight day seven was their third and final day on the lunar surface, returning to orbit to rejoin Mattingly in the Command/Service Module following the day's moonwalk. During the third and final lunar excursion, they were to explore North Ray Crater, the largest of any of the craters any Apollo expedition had visited. After exiting Orion, the pair drove the lunar rover 0.8 km (0.50 mi) away from the LM before adjusting their heading to travel 1.4 km (0.87 mi) to North Ray Crater. The drive was smoother than that of the previous day, as the craters were shallower and boulders were less abundant north of the immediate landing site. After passing Palmetto crater, boulders gradually became larger and more abundant as they approached North Ray in the lunar rover. Upon arriving at the rim of North Ray crater, they were 4.4 km (2.7 mi) away from the LM. After their arrival, the duo took photographs of the 1 km (0.62 mi) wide and 230 m (750 ft) deep crater. They visited a large boulder, taller than a four-story building, which became known as 'House Rock'. Samples obtained from this boulder delivered the final blow to the pre-mission volcanic hypothesis, proving it incorrect. House Rock had numerous bullet hole-like marks where micrometeoroids from space had impacted the rock. About 1 hour and 22 minutes after arriving, they departed for station 13, a large boulder field about 0.5 km (0.31 mi) from North Ray. On the way, they set a lunar speed record, traveling at an estimated 17.1 kilometers per hour (10.6 mph) downhill. They arrived at a 3 m (9.8 ft) high boulder, which they called 'Shadow Rock'. Here, they sampled permanently shadowed soil. During this time, Mattingly was preparing the Command/Service Module in anticipation of their return approximately six hours later. After three hours and six minutes, they returned to the LM, where they completed several experiments and offloaded the rover. A short distance from the LM, Duke placed a photograph of his family and a United States Air Force commemorative medallion on the surface.[54] Young drove the rover to a point about 90 m (300 ft) east of the LM, known as the 'VIP site,' so its television camera, controlled remotely by Mission Control, could observe Apollo 16's liftoff from the Moon. They then reentered the LM after a 5-hour and 40 minute final excursion.[67] After pressurizing the LM cabin, the crew began preparing to return to lunar orbit.[68]

Return to Earth[edit]

Eight minutes before departing the lunar surface, CAPCOM James Irwin notified Young and Duke from Mission Control that they were go for liftoff. Two minutes before launch, they activated the "Master Arm" switch and then the "Abort Stage" button, after which they awaited ignition of Orion’s ascent stage engine. When the ascent stage ignited, small explosive charges severed the ascent stage from the descent stage and cables connecting the two were severed by a guillotine-like mechanism. Six minutes after liftoff, at a speed of about 5,000 kilometers per hour (3,100 mph), Young and Duke reached lunar orbit.[54][69] Young and Duke successfully rendezvoused and re-docked with Mattingly in the Command/Service Module. To minimize the transfer of lunar dust from the LM cabin into the CSM, Young and Duke cleaned the cabin before opening the hatch separating the two spacecraft. After opening the hatch and reuniting with Mattingly, the crew transferred the samples Young and Duke had collected on the surface into the CSM for transfer to Earth. After transfers were completed, the crew would sleep before jettisoning the empty Lunar Module ascent stage the next day, when it was to be crashed intentionally into the lunar surface.[37]

The next day, after final checks were completed, the expended LM ascent stage was jettisoned.[70] Because of a failure by the crew to activate a certain switch in the LM before sealing it off, it initially tumbled after separation and did not execute the rocket burn necessary for the craft's intentional de-orbit. The ascent stage eventually crashed into the lunar surface nearly a year after the mission. The crew's next task, after jettisoning the Lunar Module ascent stage, was to release a subsatellite into lunar orbit from the CSM's Scientific Instrument Bay. The burn to alter the CSM's orbit to that desired for the subsatellite had been cancelled; as a result, the subsatellite lasted half of its anticipated lifetime. Just under five hours later, on the CSM's 65th orbit around the Moon, its Service Propulsion System main engine was reignited to propel the craft on a trajectory that would return it to Earth. The SPS engine performed the burn flawlessly despite the malfunction that had delayed the lunar landing several days before.[37][70]

At a distance of about 170,000 nautical miles (310,000 km) from Earth, Mattingly performed a "deep-space" extra-vehicular activity, or spacewalk, during which he retrieved several film cassettes from the CSM's SIM bay. While outside the spacecraft, Mattingly set up a biological experiment, the Microbial Ecology Evaluation Device (MEED).[71] The MEED experiment was only performed on Apollo 16.[72] The crew carried out various housekeeping and maintenance tasks aboard the spacecraft and ate a meal before concluding the day.[71]

The penultimate day of the flight was largely spent performing experiments, aside from a twenty-minute press conference during the second half of the day. During the press conference, the astronauts answered questions pertaining to several technical and non-technical aspects of the mission prepared and listed by priority at the Manned Spacecraft Center in Houston by journalists covering the flight. In addition to numerous housekeeping tasks, the astronauts prepared the spacecraft for its atmospheric reentry the next day. At the end of the crew's final full day in space, the spacecraft was approximately 77,000 nautical miles (143,000 km) from Earth and closing at a rate of about 7,000 feet per second (2,100 m/s).[73][74]

When the wake-up call was issued to the crew for their final day in space by CAPCOM Tony England, it was about 45,000 nautical miles (83,000 km) out from Earth, traveling just over 9,000 ft/s (2,700 m/s). Just over three hours before splashdown in the Pacific Ocean, the crew performed a final course correction burn, changing their velocity by 1.4 ft/s (0.43 m/s). Approximately ten minutes before reentry into Earth's atmosphere, the cone-shaped Command Module containing the three crewmembers separated from the Service Module, which would burn up during reentry. At 265 hours and 37 minutes into the mission, at a velocity of about 36,000 ft/s (11,000 m/s), Apollo 16 began atmospheric reentry. At its maximum, the temperature of the heat shield was between 4,000 and 4,500 °F (2,200 and 2,480 °C). After successful parachute deployment and less than 14 minutes after reentry began, the Command Module splashed down in the Pacific Ocean 350 km (220 mi) southeast of the island of Kiritimati (or "Christmas Island"), 290 hours, 37 minutes, 6 seconds after liftoff. The spacecraft and its crew was retrieved by USS Ticonderoga. They were safely aboard the Ticonderoga 37 minutes after splashdown.[37][75]

Lunar subsatellite PFS-2[edit]

The Apollo 16 subsatellite (PFS-2) was a small satellite released into lunar orbit from the Service Module. Its principal objective was to measure charged particles and magnetic fields all around the Moon as the Moon orbited Earth, similar to its sister spacecraft, PFS-1, released eight months earlier by Apollo 15. "The low orbits of both subsatellites were to be similar ellipses, ranging from 55 to 76 miles (89 to 122 kilometres) above the lunar surface."[76]

"Instead, something bizarre happened. The orbit of PFS-2 rapidly changed shape and distance from the Moon. In 2-1/2 weeks the satellite was swooping to within a hair-raising 6 miles (9.7 km) of the lunar surface at closest approach. As the orbit kept changing, PFS-2 backed off again, until it seemed to be a safe 30 miles away. But not for long: inexorably, the subsatellite's orbit carried it back toward the Moon. And on May 29, 1972—only 35 days and 425 orbits after its release"—PFS-2 crashed into the Lunar surface.[76]

In later years, through a study of many lunar orbiting satellites, scientists came to discover that most low lunar orbits (LLO) are unstable. PFS-2 had been placed, unknown to mission planners at the time, squarely into one of the most unstable of orbits, at 11 degrees orbital inclination, far from the four frozen lunar orbits discovered only later at 27°, 50°, 76°, and 86° inclination.[76]

Spacecraft locations[edit]

The aircraft carrier USS Ticonderoga delivered the Apollo 16 Command Module to the North Island Naval Air Station, near San Diego, California, on Friday, May 5, 1972. On Monday, May 8, 1972, ground service equipment being used to empty the residual toxic reaction control system fuel in the Command Module tanks exploded in a Naval Air Station hangar. Forty-six people were sent to the hospital for 24 to 48 hours observation, most suffering from inhalation of toxic fumes. Most seriously injured was a technician who suffered a fractured kneecap when the GSE cart overturned on him. A hole was blown in the hangar roof 250 feet above; about 40 windows in the hangar were shattered. The Command Module suffered a three-inch gash in one panel.[77][78][79]

The Apollo 16 Command Module Casper is on display at the U.S. Space & Rocket Center in Huntsville, Alabama. The Lunar Module ascent stage separated 24 April 1972 but a loss of attitude control rendered it out of control. It orbited the Moon for about a year. Its impact site remains unknown.[80] The S-IVB was deliberately crashed into the moon. However, due to a communication failure before impact the exact location was unknown until January 2016, when it was discovered within Mare Insularum by the Lunar Reconnaissance Orbiter, approximately 160 mi (260 km) southwest of Copernicus Crater.[37][80][81]

Duke donated some flown items, including a lunar map, to Kennesaw State University in Kennesaw, Georgia. He left two items on the Moon, both of which he photographed. The most famous is a plastic-encased photo portrait of his family (NASA Photo AS16-117-18841[82]). The reverse of the photo is signed by Duke's family and bears this message: "This is the family of Astronaut Duke from Planet Earth. Landed on the Moon, April 1972." The other item was a commemorative medal issued by the United States Air Force, which was celebrating its 25th anniversary in 1972. He took two medals, leaving one on the Moon and donating the other to the Wright-Patterson Air Force Base museum.[83]

In 2006, shortly after Hurricane Ernesto affected Bath, North Carolina, eleven-year-old Kevin Schanze discovered a piece of metal debris on the ground near his beach home. Schanze and a friend discovered a "stamp" on the 36-inch (91 cm) flat metal sheet, which upon further inspection turned out to be a faded copy of the Apollo 16 mission insignia. NASA later confirmed the object to be a piece of the first stage of the Saturn V rocket that launched Apollo 16 into space. In July 2011, after returning the piece of debris at NASA's request, 16-year-old Schanze was given an all-access tour of the Kennedy Space Center and VIP seating for the launch of STS-135, the final mission of the Space Shuttle program.[84]

See also[edit]


 This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.

Location of the Apollo 16 landing site
Oblique closeup of the proposed Apollo 16 landing site as photographed by Apollo 14 from lunar orbit. North Ray crater is at left and South Ray crater is at right, with bright rays.
Earth from Apollo 16 during the trans-lunar coast
The lunar surface through a Lunar Module window shortly after landing
The view from the side of Stone Mountain
John Young stands in the shadow of Shadow Rock
Charlie Duke left a photo of his family on the Moon. Cat Crater at Station 14 was named for sons Charles And Tom. Dot Crater at Station 16 was named for his wife.[66]
Launch of the ascent stage of the Apollo 16 Lunar Module from the lunar surface
Ken Mattingly performs his deep-space EVA, retrieving film cassettes from the CSM's exterior
Artist's conception of subsatellite deployment

This article is about the rocket. For the fifth moon of Saturn, see Rhea (moon).

The final manned Saturn V, AS-512, before the launch of Apollo 17 in December 1972

Country of originUnited States
Project cost$6.417 billion in 1964–1973 dollars[1]
Cost per launch$185 million in 1969–1971 dollars[2] ($1.16 billion in 2016 value), of which $110 million was for vehicle.[3]
Height363.0 ft (110.6 m)
Diameter33.0 ft (10.1 m)
Mass6,540,000 lb (2,970,000 kg)[4]
Payload to LEO (90 nmi (170 km), 30° inclination)310,000 lb (140,000 kg)[5][6][note 1]
Payload to TLI107,100 lb (48,600 kg)[4]
Associated rockets
DerivativesSaturn INT-21
Launch history
Launch sitesLC-39, Kennedy Space Center
Total launches13
Partial failures1 (Apollo 6)
First flightNovember 9, 1967 (AS-501[note 2]Apollo 4)
Last flightMay 14, 1973 (AS-513 Skylab 1)
First stage – S-IC
Length138.0 ft (42.1 m)
Diameter33.0 ft (10.1 m)
Empty mass287,000 lb (130,000 kg)
Gross mass5,040,000 lb (2,290,000 kg)
Engines5 Rocketdyne F-1
Thrust7,891,000 lbf (35,100 kN) sea level
Specific impulse263 seconds (2.58 km/s) sea level
Burn time168 seconds
Second stage – S-II
Length81.5 ft (24.8 m)
Diameter33.0 ft (10.1 m)
Empty mass88,400 lb (40,100 kg)[note 3]
Gross mass1,093,900 lb (496,200 kg)[note 3]
Engines5 Rocketdyne J-2
Thrust1,155,800 lbf (5,141 kN) vacuum
Specific impulse421 seconds (4.13 km/s) vacuum
Burn time360 seconds
Third stage – S-IVB
Length61.6 ft (18.8 m)
Diameter21.7 ft (6.6 m)
Empty mass29,700 lb (13,500 kg)[4][note 4]
Gross mass271,000 lb (123,000 kg)[note 4]
Engines1 Rocketdyne J-2
Thrust225,000 lbf (1,000 kN) vacuum
Specific impulse421 seconds (4.13 km/s) vacuum
Burn time165 + 335 seconds (2 burns)

The Saturn V (pronounced "Saturn five") was an American human-ratedexpendablerocket used by NASA between 1967 and 1973.[7] The three-stageliquid-fueledsuper heavy-lift launch vehicle was developed to support the Apollo program for human exploration of the Moon and was later used to launch Skylab, the first American space station. The Saturn V was launched 13 times from the Kennedy Space Center in Florida with no loss of crew or payload. As of 2018, [update]the Saturn V remains the tallest, heaviest, and most powerful (highest total impulse) rocket ever brought to operational status, and holds records for the heaviest payload launched and largest payload capacity to low Earth orbit (LEO) of 140,000 kg (310,000 lb), which included the third stage and unburned propellant needed to send the Apollo Command/Service Module and Lunar Module to the Moon.[5][6]

The largest production model of the Saturn family of rockets, the Saturn V, was designed under the direction of Wernher von Braun and Arthur Rudolph at the Marshall Space Flight Center in Huntsville, Alabama, with Boeing, North American Aviation, Douglas Aircraft Company, and IBM as the lead contractors.

To date[update], the Saturn V remains the only launch vehicle to carry humans beyond low Earth orbit. A total of 15 flight-capable vehicles were built, but only 13 were flown. An additional three vehicles were built for ground testing purposes. A total of 24 astronauts were launched to the Moon, three of them twice, in the four years spanning December 1968 through December 1972.

Historical background[edit]

Main article: Space Race

The origins of the Saturn V rocket begin with the US government bringing Wernher von Braun along with about seven hundred German rocket engineers and technicians to the United States in Operation Paperclip, a program authorized by President Truman in August 1946 with the purpose of harvesting Germany's rocket expertise, to give the US an edge in the Cold War through development of intermediate-range (IRBM) and intercontinental ballistic missiles (ICBM). It was known that America's rival, the Soviet Union, would also try to secure some of the Germans.

Von Braun was put into the rocket design division of the Army due to his prior direct involvement in the creation of the V-2 rocket.[8] Between 1945 and 1958, his work was restricted to conveying the ideas and methods behind the V-2 to the American engineers.[citation needed] Despite Von Braun's many articles on the future of space rocketry, the US Government continued funding Air Force and Navy rocket programs to test their Vanguard missiles in spite of numerous costly failures. It was not until the 1957 Soviet launch of Sputnik 1 atop an R-7ICBM capable of carrying a thermonuclear warhead to the US,[9][10] that the Army and the government started taking serious steps towards putting Americans in space.[11] Finally, they turned to von Braun and his team, who during these years created and experimented with the Jupiter series of rockets. The Juno I was the rocket that launched the first American satellite in January 1958, and part of the last-ditch plan for NACA (the predecessor of NASA) to get its foot in the Space Race.[12] The Jupiter series was one more step in von Braun's journey to the Saturn V, later calling that first series "an infant Saturn".[11]

Saturn development[edit]

Main article: Saturn (rocket family)

The Saturn V's design stemmed from the designs of the Jupiter series rockets. As the success of the Jupiter series became evident, the Saturn series emerged.

C-1 to C-4[edit]

Between 1960 and 1962, the Marshall Space Flight Center (MSFC) designed a series of Saturn rockets that could be used for various Earth orbit or lunar missions.

The C-1 was developed into the Saturn I, and the C-2 rocket was dropped early in the design process in favor of the C-3, which was intended to use two F-1 engines on its first stage, four J-2 engines for its second stage, and an S-IV stage, using six RL10 engines.

NASA planned to use the C-3 as part of the Earth Orbit Rendezvous (EOR) concept, with at least four or five launches needed for a single lunar mission.[citation needed] But MSFC was already planning an even bigger rocket, the C-4, which would use four F-1 engines on its first stage, an enlarged C-3 second stage, and the S-IVB, a stage with a single J-2 engine, as its third stage. The C-4 would need only two launches to carry out an EOR lunar mission.[citation needed]


On January 10, 1962, NASA announced plans to build the C-5. The three-stage rocket would consist of: the S-IC first stage, with five F-1 engines; the S-II second stage, with five J-2 engines; and the S-IVB third stage, with a single J-2 engine.[13] The C-5 was designed for a 90,000-pound (41,000 kg) payload capacity to the Moon.[13]

The C-5 would undergo component testing even before the first model was constructed. The S-IVB third stage would be used as the second stage for the C-IB, which would serve both to demonstrate proof of concept and feasibility for the C-5, but would also provide flight data critical to development of the C-5.[13] Rather than undergoing testing for each major component, the C-5 would be tested in an "all-up" fashion, meaning that the first test flight of the rocket would include complete versions of all three stages. By testing all components at once, far fewer test flights would be required before a manned launch.[14]

The C-5 was confirmed as NASA's choice for the Apollo program in early 1963, and was named the Saturn V.[13] The C-1 became the Saturn I, and C-1B became Saturn IB. Von Braun headed a team at the Marshall Space Flight Center in building a vehicle capable of launching a manned spacecraft on a trajectory to the Moon.[11] Before they moved under NASA's jurisdiction, von Braun's team had already begun work on improving the thrust, creating a less complex operating system, and designing better mechanical systems.[11] It was during these revisions that the decision to reject the single engine of the V-2's design came about, and the team moved to a multiple-engine design. The Saturn I and IB reflected these changes, but were not large enough to send a manned spacecraft to the Moon.[11] These designs, however, provided a basis for which NASA could determine its best method towards landing a man on the Moon.

The Saturn V's final design had several key design features. Engineers determined that the best engines were the F-1s coupled with the new liquid hydrogen propulsion system called J-2, which made the Saturn C-5 configuration optimal.[11] By 1962, NASA had finalized its plans to proceed with von Braun's Saturn designs, and the Apollo space program gained speed.[15]

With the configuration finalized, NASA turned its attention to mission profiles. Despite some controversy, a lunar orbit rendezvous for the lunar module was chosen over an Earth orbital rendezvous.[11] Issues such as type of fuel injections, the needed amount of fuel for such a trip, and rocket manufacturing processes were ironed out, and the designs for the Saturn V were selected. The stages were designed by von Braun's Marshall Space Flight Center in Huntsville, and outside contractors were chosen for the construction: Boeing (S-IC), North American Aviation (S-II), Douglas Aircraft (S-IVB), and IBM (Instrument Unit).[15]

Selection for Apollo lunar landing[edit]

See also: Project Apollo § Choosing a mission mode

Early in the planning process, NASA considered three leading ideas for the Moon mission: Earth Orbit Rendezvous, Direct Ascent, and Lunar Orbit Rendezvous (LOR). A direct ascent configuration would launch a larger rocket which would land directly on the lunar surface, while an Earth orbit rendezvous would launch two smaller spacecraft which would combine in Earth orbit. A LOR mission would involve a single rocket launching a single spacecraft, but only a small part of that spacecraft would land on the moon. That smaller landing module would then rendezvous with the main spacecraft, and the crew would return home.[16]

NASA at first dismissed LOR as a riskier option, given that an orbital rendezvous had yet to be performed in Earth orbit, much less in lunar orbit. Several NASA officials, including Langley Research Center engineer John Houbolt and NASA Administrator George Low, argued that a Lunar Orbit Rendezvous provided the simplest landing on the moon, the most cost–efficient launch vehicle and, perhaps most importantly, the best chance to accomplish a lunar landing within the decade.[13] Other NASA officials were convinced, and LOR was officially selected as the mission configuration for the Apollo program on November 7, 1962.[13]


The Saturn V's size and payload capacity dwarfed all other previous rockets which had successfully flown at that time. With the Apollo spacecraft on top, it stood 363 feet (111 m) tall, and without fins, it was 33 feet (10 m) in diameter. Fully fueled, the Saturn V weighed 6.5 million pounds (2,950 metric tons)[4] and had a low Earth orbit payload capacity originally estimated at 261,000 pounds (118,000 kg),[17] but was designed to send at least 90,000 pounds (41,000 kg) to the Moon. Later upgrades increased that capacity; during the final three Apollo lunar missions it deployed about 310,000 pounds (140,000 kg)[5][6][note 1] to LEO and sent up to 107,100 lb (48,600 kg)[4] spacecraft to the Moon. At a height of 363 feet (111 m), the Saturn V was 58 feet (18 m) taller than the Statue of Liberty from the ground to the torch, and 48 feet (15 m) taller than the Big Ben clock tower.[18]

In contrast, the Mercury-Redstone Launch Vehicle used on Freedom 7, the first manned American spaceflight, was just under 11 feet (3.4 m) longer than the S-IVB stage, and delivered less sea level thrust (78,000 pounds-force (350 kN)) than the Launch Escape System rocket (150,000 pounds-force (667 kN) sea level thrust) mounted atop the Apollo Command Module.[19]

The Saturn V was principally designed by the Marshall Space Flight Center in Huntsville, Alabama, although numerous major systems, including propulsion, were designed by subcontractors. It used the powerful new F-1 and J-2rocket engines for propulsion. When tested, these engines shattered the windows of nearby houses.[20] Designers decided early on to attempt to use as much technology from the Saturn I program as possible. Consequently, the S-IVB-500 third stage of the Saturn V was based on the S-IVB-200 second stage of the Saturn IB. The Instrument Unit that controlled the Saturn V shared characteristics with that carried by the Saturn IB.

Blueprints and other Saturn V plans are available on microfilm at the Marshall Space Flight Center.[21]


The Saturn V consisted of three stages—the S-IC first stage, S-II second stage and the S-IVB third stage—and the instrument unit. All three stages used liquid oxygen (LOX) as an oxidizer. The first stage used RP-1 for fuel, while the second and third stages used liquid hydrogen (LH2). The upper stages also used small solid-fueled ullage motors that helped to separate the stages during the launch, and to ensure that the liquid propellants were in a proper position to be drawn into the pumps.

S-IC first stage[edit]

Main article: S-IC

The S-IC was built by the Boeing Company at the Michoud Assembly Facility, New Orleans, where the Space ShuttleExternal Tanks would later be built by Lockheed Martin. Most of its mass at launch was propellant, RP-1 fuel with liquid oxygen as the oxidizer.[22] It was 138 feet (42 m) tall and 33 feet (10 m) in diameter, and provided over 7,600,000 pounds-force (34,000 kN) of thrust. The S-IC stage had a dry weight of about 289,000 pounds (131 metric tons) and fully fueled at launch had a total weight of 5,100,000 pounds (2,300 metric tons). It was powered by five Rocketdyne F-1 engines arrayed in a quincunx (five units, with four arranged in a square, and the fifth in the center) The center engine was held in a fixed position, while the four outer engines could be hydraulically turned (gimballed) to steer the rocket.[22] In flight, the center engine was turned off about 26 seconds earlier than the outboard engines to limit acceleration. During launch, the S-IC fired its engines for 168 seconds (ignition occurred about 8.9 seconds before liftoff) and at engine cutoff, the vehicle was at an altitude of about 36 nautical miles (67 km), was downrange about 50 nautical miles (93 km), and was moving about 7,500 feet per second (2,300 m/s).[23]

S-II second stage[edit]

Main article: S-II

The S-II was built by North American Aviation at Seal Beach, California. Using liquid hydrogen and liquid oxygen, it had five Rocketdyne J-2 engines in a similar arrangement to the S-IC, also using the outer engines for control. The S-II was 81.6 feet (24.87 m) tall with a diameter of 33 feet (10 m), identical to the S-IC, and thus was the largest cryogenic stage until the launch of the Space Shuttle in 1981. The S-II had a dry weight of about 80,000 pounds (36,000 kg) and fully fueled, weighed 1,060,000 pounds (480,000 kg). The second stage accelerated the Saturn V through the upper atmosphere with 1,100,000 pounds-force (4,900 kN) of thrust in vacuum. When loaded, significantly more than 90 percent of the mass of the stage was propellant; however, the ultra-lightweight design had led to two failures in structural testing. Instead of having an intertank structure to separate the two fuel tanks as was done in the S-IC, the S-II used a common bulkhead that was constructed from both the top of the LOX tank and bottom of the LH2 tank. It consisted of two aluminum sheets separated by a honeycomb structure made of phenolic resin. This bulkhead had to insulate against the 126 °F (70 °C) temperature gradient between the two tanks. The use of a common bulkhead saved 7,900 pounds (3.6 t). Like the S-IC, the S-II was transported from its manufacturing plant to the Cape by sea.

S-IVB third stage[edit]

Main article: S-IVB

The S-IVB was built by the Douglas Aircraft Company at Huntington Beach, California. It had one J-2 engine and used the same fuel as the S-II. The S-IVB used a common bulkhead to separate the two tanks. It was 58.6 feet (17.86 m) tall with a diameter of 21.7 feet (6.604 m) and was also designed with high mass efficiency, though not quite as aggressively as the S-II. The S-IVB had a dry weight of about 23,000 pounds (10,000 kg) and, fully fueled, weighed about 262,000 pounds (119,000 kg).[24]

The S-IVB-500 model used on the Saturn V differed from the S-IVB-200 used as the second stage of the Saturn IB, in that the engine was restartable once per mission. This was necessary as the stage would be used twice during a lunar mission: first in a 2.5 min burn for the orbit insertion after second stage cutoff, and later for the trans-lunar injection (TLI) burn, lasting about 6 min. Two liquid-fueled Auxiliary Propulsion System (APS) units mounted at the aft end of the stage were used for attitude control during the parking orbit and the trans-lunar phases of the mission. The two APSs were also used as ullage engines to settle the propellants in the aft tank engine feed lines prior to the trans-lunar injection burn.

The S-IVB was the only rocket stage of the Saturn V small enough to be transported by plane, in this case the Pregnant Guppy.

Instrument Unit[edit]

Main article: Saturn V Instrument Unit

The Instrument Unit was built by IBM and rode atop the third stage. It was constructed at the Space Systems Center in Huntsville, Alabama. This computer controlled the operations of the rocket from just before liftoff until the S-IVB was discarded. It included guidance and telemetry systems for the rocket. By measuring the acceleration and vehicle attitude, it could calculate the position and velocity of the rocket and correct for any deviations.

Range safety[edit]

In the event of an abort requiring the destruction of the rocket, the range safety officer would remotely shut down the engines and after several seconds send another command for the shaped explosive charges attached to the outer surfaces of the rocket to detonate. These would make cuts in fuel and oxidizer tanks to disperse the fuel quickly and to minimize mixing. The pause between these actions would give time for the crew to escape using the Launch Escape Tower or (in the later stages of the flight) the propulsion system of the Service module. A third command, "safe", was used after the S-IVB stage reached orbit to irreversibly deactivate the self-destruct system. The system was also inactive as long as the rocket was still on the launch pad.[25]


Titan II[edit]

The Saturn V had a much lower thrust-to-weight ratio than Project Gemini's Titan II GLV. Richard F. Gordon, Jr. described Saturn as "an old man's ride", with "a lot more shake-rattle-and-roll" but milder thrust. Buzz Aldrin and other Apollo 11 astronauts agreed that they could not tell when Saturn liftoff occurred except from instruments, unlike on Titan.[26]

Soviet N1-L3[edit]

The Soviet space program's counterpart to the Saturn V was Sergei Korolev's N1-L3. The Saturn V was taller, heavier, and had greater payload capacity, both to low Earth orbit and to translunar injection.[27] The N-1 was a three-stage launch vehicle with more liftoff thrust and a larger first stage diameter than the Saturn V.[28] It was to carry the 209,000 lb (95,000 kg) L3 vehicle into orbit. The L3 contained an Earth departure stage, which would send to the Moon a 51,800 lb (23,500 kg) package which contained another stage for lunar orbit insertion and powered descent initiation, a single-cosmonautlander, and a two-cosmonaut lunar orbiter for the return to Earth. The N1/L3 would have produced more total impulse (product of thrust and time) in its first four stages than the three-stage Saturn V, but it was not able to convert as much of this into payload momentum (product of mass and velocity).

The N1 never became operational; four test launches each resulted in catastrophic vehicle failure early in flight, and the program was canceled. Korolev elected to cluster 30 relatively small engines for the first stage, rather than develop a large engine like the Rocketdyne F-1.

The three-stage Saturn V grew over its lifetime to a peak thrust of at least 7,650,000 lbf (34,020 kN) (AS-510 and subsequent)[29] and a lift capacity of 310,000 lb (140,000 kg) to LEO. The AS-510 mission (Apollo 15) had a liftoff thrust of 7,823,000 lbf (34,800 kN). The AS-513 mission (Skylab 1) had slightly greater liftoff thrust of 7,891,000 lbf (35,100 kN). By comparison, the N-1 had a sea-level liftoff thrust of about 10,200,000 lbf (45,400 kN).[30] No other operational launch vehicle has ever surpassed the Saturn V in height, weight, total impulse, or payload capability. The closest contenders were the US Space Shuttle and the Soviet Energia.

Saturn V (Apollo 11)[31]N1-L3
Diameter, maximum33 ft (10 m)56 ft (17 m)
Height w/ payload363 ft (111 m)344 ft (105 m)
Gross weight6,478,000 lb (2,938 t)6,030,000 lb (2,735 t)
First stageS-ICBlock A
Thrust, SL7,500,000 lbf (33,000 kN)10,200,000 lbf (45,400 kN)
Burn time, s168125
Second stageS-IIBlock B
Thrust, vac1,155,800 lbf (5,141 kN)3,160,000 lbf (14,040 kN)
Burn time, s384120
Orbital insertion stageS-IVB (burn 1)Block V
Thrust, vac202,600 lbf (901 kN)360,000 lbf (1,610 kN)
Burn time, s147370
Total impulse[32]1.7336×109 lbf (7.711×106 kN)·s1.789×109 lbf (7.956×106 kN)·s
Orbital payload264,900 lb (120.2 t)[33]209,000 lb (95 t)
Injection velocity25,568 ft/s (7,793 m/s)25,570 ft/s (7,793 m/s)[34]
Payload momentum2.105×108slug-ft/s (9.363×108 kg·m/s)1.6644×108 slug-ft/s (7.403×108 kg·m/s)
Propulsive efficiency12.14%9.31%
Earth departure stageS-IVB (burn 2)Block G
Thrust, vac201,100 lbf (895 kN)100,000 lbf (446 kN)
Burn time, s347443
Total impulse[32]1.8034×109 lbf (8.022×106 kN)·s1.833×109 lbf (8.153×106 kN)·s
Translunar payload100,740 lb (45.69 t)52,000 lb (23.5 t)
Injection velocity35,545 ft/s (10,834 m/s)35,540 ft/s (10,834 m/s)[34]
Payload momentum1.1129×108 slug-ft/s (4.95×108 kg·m/s)5.724×107 slug-ft/s (2.546×108 kg·m/s)
Propulsive efficiency6.17%3.12%

U.S. Space Shuttle[edit]

The Space Shuttle generated a peak thrust of 6,800,000 lbf (30,100 kN),[35] and payload capacity to LEO (excluding the Orbiter itself) was 63,500 pounds (28,800 kg), which was about 25 percent of the Saturn V's payload. Total mass in orbit, including the Orbiter, was about 247,000 lb (112,000 kg), compared to the Apollo 15 total orbital mass of the S-IVB third stage and Apollo spacecraft, of 309,771 lb (140,510 kg),[36] some 62,800 lb (28,500 kg) heavier than the Shuttle was rated to carry to LEO.

Soviet Energia/Buran[edit]

Energia had a liftoff thrust of 7,826,000 lbf (34,810 kN),[37] and flew twice in 1987 and 1988, the second time as the launcher for the Buran shuttle. However, both the Energia and Buran programs were cancelled in 1993. Hypothetical future versions of Energia might have been significantly more powerful than the Saturn V, delivering 10,000,000 lbf (46,000 kN) of thrust and able to deliver up to 386,000 lb (175 t) to LEO in the "Vulkan" configuration. Planned uprated versions of the Saturn V using F-1A engines would have had about 18 percent more thrust and 302,580 pounds (137,250 kg) payload.[38] NASA contemplated building larger members of the Saturn family, such as the Saturn C-8, and also unrelated rockets, such as Nova, but these were never produced.

Other US vehicles[edit]

Some other recent US launch vehicles have significantly lower launch capacity to LEO than Saturn V: the US Delta 4 Heavy capacity is 63,470 lb (28,790 kg), the Atlas V 551 has a capacity of 41,478 lb (18,814 kg), and the SpaceXFalcon Heavy has a capacity of 140,700 lb (63,800 kg). The European Ariane 5 ES delivers up to 46,000 lb (21,000 kg) and the Russian Proton-M can launch 49,000 lb (22,000 kg).

Space Launch System[edit]

NASA's Space Launch System, planned for its first flight in 2020, in its final configuration is planned to be 400 feet (120 m) tall with payload, and lift up to 290,000 pounds (130,000 kg) into low Earth orbit.[39]

S-IC thrust comparisons[edit]

Because of its large size, attention is often[citation needed] focused on the S-IC thrust and how this compares to other large rockets. However, several factors make such comparisons more complex than first appears:

  • Commonly referenced thrust numbers are a specification, not an actual measurement. Individual stages and engines may fall short or exceed the specification, sometimes significantly.
  • The F-1 thrust specification was uprated beginning with Apollo 15 (SA-510) from 1,500,000 lbf (6,670 kN) to 1,520,000 lbf (6,770 kN), yielding 7,610,000 lbf (33,850 kN) for the S-IC stage. The higher thrust was achieved via a redesign of the injector orifices and a slightly higher propellant mass flow rate. However, comparing the specified number to the actual measured thrust of 7,800,000 lbf (34,800 kN) on Apollo 15 shows a significant difference.
  • There is no way to directly measure thrust of a rocket in flight; Rather, a mathematical calculation is made from combustion chamber pressure, turbopump speed, calculated propellant density and flow rate, nozzle design, and atmospheric pressure.
  • Thrust varies greatly with external pressure and thus with altitude, even for a non-throttled engine. For example, on Apollo 15, the calculated total liftoff thrust (based on actual measurements) was about 7,830,000 lbf (34,810 kN), which increased to 9,200,000 lbf (40,800 kN) at T+135 seconds, just before center engine cutoff (CECO), at which time the jet was heavily underexpanded.
  • Thrust specifications are often given as vacuum thrust (for upper stages) or sea level thrust (for lower stages or boosters), sometimes without qualifying which one. This can lead to incorrect comparisons.
  • Thrust specifications are often given as average thrust or peak thrust, sometimes without qualifying which one. Even for a non-throttled engine at a fixed altitude, thrust can often vary somewhat over the firing period due to several factors. These include intentional or unintentional mixture ratio changes, slight propellant density changes over the firing period, and variations in turbopump, nozzle and injector performance over the firing period.

Without knowing the exact measurement technique and mathematical method used to determine thrust for each different rocket, comparisons are often inexact. As the above shows, the specified thrust often differs significantly from actual flight thrust calculated from direct measurements. The thrust stated in various references is often not adequately qualified as to vacuum vs sea level, or peak vs average thrust.

Similarly, payload increases are often achieved in later missions independent of engine thrust. This is by weight reduction or trajectory reshaping.

The result is there is no single absolute figure for engine thrust, stage thrust or vehicle payload. There are specified values and actual flight values, and various ways of measuring and deriving those actual flight values.

The performance of each Saturn V launch was extensively analyzed and a Launch Evaluation Report produced for each mission, including a thrust/time graph for each vehicle stage on each mission.


After the construction and ground testing of a stage was completed, it was then shipped to the Kennedy Space Center. The first two stages were so large that the only way to transport them was by barge. The S-IC, constructed in New Orleans, was transported down the Mississippi River to the Gulf of Mexico. After rounding Florida, it was then transported up the Intra-Coastal Waterway to the Vehicle Assembly Building (originally called the Vertical Assembly Building). This was essentially the same route which would be used later by NASA to ship Space Shuttle External Tanks. The S-II was constructed in California and thus traveled to Florida via the Panama Canal. The third stage and Instrument Unit could be carried by the Aero SpacelinesPregnant Guppy and Super Guppy, but could also have been carried by barge if warranted.

On arrival at the Vertical Assembly Building, each stage was inspected in a horizontal position before being moved to a vertical position. NASA also constructed large spool-shaped structures that could be used in place of stages if a particular stage was late. These spools had the same height and mass and contained the same electrical connections as the actual stages.

NASA stacked or assembled the Saturn V on a Mobile Launcher Platform (MLP), which consisted of a Launch Umbilical Tower (LUT) with nine swing arms (including the crew access arm), a "hammerhead" crane, and a water suppression system which was activated prior to launch. After assembly was completed, the entire stack was moved from the VAB to the launch pad using the Crawler Transporter (CT). Built by the Marion Power Shovel company (and later used for transporting the smaller and lighter Space Shuttle), the CT ran on four double-tracked treads, each with 57 'shoes'. Each shoe weighed 2,000 pounds (910 kg). This transporter was also required to keep the rocket level as it traveled the 3 miles (4.8 km) to the launch site, especially at the 3 percent grade encountered at the launch pad. The CT also carried the Mobile Service Structure (MSS), which allowed technicians access to the rocket until eight hours before launch, when it was moved to the "halfway" point on the Crawlerway (the junction between the VAB and the two launch pads).

Lunar mission launch sequence[edit]

The Saturn V carried all Apollo lunar missions. All Saturn V missions were launched from Launch Complex 39 at the John F. Kennedy Space Center in Florida. After the rocket cleared the launch tower, flight control transferred to Johnson Space Center's Mission Control in Houston, Texas.

An average mission used the rocket for a total of just 20 minutes. Although Apollo 6 experienced three engine failures,[41] and Apollo 13 one engine shutdown,[42] the onboard computers were able to compensate by burning the remaining engines longer to achieve parking orbit. None of the Saturn V launches resulted in a payload loss.

S-IC sequence[edit]

The first stage burned for about 2 minutes and 41 seconds, lifting the rocket to an altitude of 42 miles (68 km) and a speed of 6,164 miles per hour (2,756 m/s) and burning 4,700,000 pounds (2,100,000 kg) of propellant.[43]

At 8.9 seconds before launch, the first stage ignition sequence started. The center engine ignited first, followed by opposing outboard pairs at 300-millisecond intervals to reduce the structural loads on the rocket. When thrust had been confirmed by the onboard computers, the rocket was "soft-released" in two stages: first, the hold-down arms released the rocket, and second, as the rocket began to accelerate upwards, it was slowed by tapered metal pins pulled through dies for half a second. Once the rocket had lifted off, it could not safely settle back down onto the pad if the engines failed. The astronauts considered this one of the tensest moments in riding the Saturn V, for if the rocket did fail to lift off after release they had a low chance of survival given the large amounts of propellant. A fully fueled Saturn V exploding on the pad would have released the energy equivalent of two kilotons of TNT. To improve safety, the Saturn Emergency Detection System (EDS) inhibited engine shutdown for the first 30 seconds of flight. (See Saturn V Instrument Unit)

It took about 12 seconds for the rocket to clear the tower. During this time, it yawed 1.25 degrees away from the tower to ensure adequate clearance despite adverse winds. (This yaw, although small, can be seen in launch photos taken from the east or west.) At an altitude of 430 feet (130 m) the rocket rolled to the correct flight azimuth and then gradually pitched down until 38 seconds after second stage ignition. This pitch program was set according to the prevailing winds during the launch month. The four outboard engines also tilted toward the outside so that in the event of a premature outboard engine shutdown the remaining engines would thrust through the rocket's center of mass. The Saturn V reached 400 feet per second (120 m/s) at over 1 mile (1,600 m) in altitude. Much of the early portion of the flight was spent gaining altitude, with the required velocity coming later. The Saturn V broke the sound barrier at just over 1 minute at an altitude of between 3 and 4 nautical miles (5.5 to 7.4 kilometers). At this point, shock collars, or condensation clouds, could be seen forming around the bottom of the command module and around the top of the second stage.

At about 80 seconds, the rocket experienced maximum dynamic pressure (max Q). The dynamic pressure on a rocket varies with air density and the square of relative velocity. Although velocity continues to increase, air density decreases so quickly with altitude that dynamic pressure falls below max Q.

Acceleration increased during S-IC flight for three reasons. One, increased acceleration increased the propellant pressure at the engines, increasing the flow rate somewhat. This was the least important factor, though this feedback effect often led to an undesirable thrust oscillation called pogo. Two, as it climbed into thinner air F-1 engine efficiency increased significantly, a property of all rockets. The combined thrust of five engines on the pad was about 7.5 million pounds, reaching nearly 9 million pounds at altitude. But the biggest contribution by far was the rocket's rapidly decreasing mass. The propellant in just the S-IC made up about three-quarters of Saturn V's entire launch mass, and it was furiously consumed at over 13 metric tonnes per second. Newton's second law states that force is equal to mass multiplied by acceleration, or equivalently that acceleration is equal to force divided by mass, so as the mass decreased (and the force increased somewhat), acceleration rose. Including gravity, launch acceleration was only 1¼ g, i.e., the astronauts felt 1¼ g while the rocket accelerated vertically at ¼ g. As the rocket rapidly lost mass, total acceleration including gravity increased to nearly 4 g at T+135 seconds. At this point, the inboard (center) engine was shut down to prevent acceleration from increasing beyond 4 g.

When oxidizer or fuel depletion was sensed in the suction assemblies, the remaining four outboard engines were shut down. First stage separation occurred a little less than one second after this to allow for F-1 thrust tail-off. Eight small solid fuel separation motors backed the S-IC from the rest of the vehicle at an altitude of about 36 nautical miles (67 km). The first stage continued ballistically to an altitude of about 59 nautical miles (109 km) and then fell in the Atlantic Ocean about 300 nautical miles (560 km) downrange.

The engine shutdown procedure was changed for the launch of Skylab to avoid damage to the Apollo Telescope Mount. Rather than shutting down all four outboard engines at once, they were shut down two at a time with a delay to reduce peak acceleration further.

S-II sequence[edit]

After S-IC separation, the S-II second stage burned for 6 minutes and propelled the craft to 109 miles (175 km) and 15,647 mph (6,995 m/s), close to orbital velocity.

For the first two unmanned launches, eight solid-fuelullage motors ignited for four seconds to give positive acceleration to the S-II stage, followed by start of the five J-2 engines. For the first seven manned Apollo missions only four ullage motors were used on the S-II, and they were eliminated completely for the final four launches. About 30 seconds after first stage separation, the interstage ring dropped from the second stage. This was done with an inertially fixed attitude so that the interstage, only 1 meter from the outboard J-2 engines, would fall cleanly without contacting them. Shortly after interstage separation the Launch Escape System was also jettisoned. See Apollo abort modes for more information about the various abort modes that could have been used during a launch.

About 38 seconds after the second stage ignition the Saturn V switched from a preprogrammed trajectory to a "closed loop" or Iterative Guidance Mode. The Instrument Unit now computed in real time the most fuel-efficient trajectory toward its target orbit. If the Instrument Unit failed, the crew could switch control of the Saturn to the Command Module's computer, take manual control, or abort the flight.

About 90 seconds before the second stage cutoff, the center engine shut down to reduce longitudinal pogo oscillations. At around this time, the LOX flow rate decreased, changing the mix ratio of the two propellants, ensuring that there would be as little propellant as possible left in the tanks at the end of second stage flight. This was done at a predetermined delta-v.

Five level sensors in the bottom of each S-II propellant tank were armed during S-II flight, allowing any two to trigger S-II cutoff and staging when they were uncovered. One second after the second stage cut off it separated and several seconds later the third stage ignited. Solid fuel retro-rockets mounted on the interstage at the top of the S-II fired to back it away from the S-IVB. The S-II impacted about 2,300 nautical miles (4,200 km) from the launch site.

On the Apollo 13 mission, the inboard engine suffered from major pogo oscillation, resulting in an early automatic cutoff. To ensure sufficient velocity was reached, the remaining four engines were kept active for longer than planned. A pogo suppressor was fitted to later Apollo missions to avoid this, though the early engine 5 cutoff remained to reduce g-forces.

S-IVB sequence[edit]

Unlike the two-plane separation of the S-IC and S-II, the S-II and S-IVB stages separated with a single step. Although it was constructed as part of the third stage, the interstage remained attached to the second stage.

The first stage of Apollo 8 Saturn V being erected in the VAB on February 1, 1968
Cutaway drawing of the Saturn V S-IVB
A comparison of the U.S. Saturn V rocket with the Soviet N1-L3
Apollo 17 ascent flight parameters
Liftoff of Apollo 11, the first mission to land humans on the Moon, July 16, 1969
Apollo 11 launch pad filmed at 500 fps.
Apollo 11 S-IC separation
Still from film footage of Apollo 6's interstage falling away
Apollo 6 interstage falling away. The engine exhaust from the S-II stage glows as it impacts the interstage.

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