136-619: Powered Descent Initiation (PDI) is a term used during the Apollo program Moon landing missions to describe the maneuver of the Apollo Lunar Module as it descended from lunar orbit to a rocket-powered landing . " Eagle was GO to ignite its descent engine, and Armstrong and Aldrin locked their eyes to the glowing numbers displayed before them. They were almost at an invisible junction of height, speed, range, and time when everything would join together for commitment. When
272-432: A Seconal sleeping pill . The pill had little effect. Borman eventually fell asleep, and then awoke feeling ill. He vomited twice and had a bout of diarrhea; this left the spacecraft full of small globules of vomit and feces, which the crew cleaned up as well as they could. Borman initially did not want everyone to know about his medical problems, but Lovell and Anders wanted to inform Mission Control. The crew decided to use
408-541: A mission module cabin separate from the command module (piloting and reentry cabin), and a propulsion and equipment module . On August 30, a feasibility study competition was announced, and on October 25, three study contracts were awarded to General Dynamics/Convair , General Electric , and the Glenn L. Martin Company . Meanwhile, NASA performed its own in-house spacecraft design studies led by Maxime Faget , to serve as
544-525: A perigee of 99.57 nautical miles (184.40 km), with an inclination of 32.51° to the Equator , and an orbital period of 88.19 minutes. Propellant venting increased the apogee by 6.4 nautical miles (11.9 km) over the 2 hours, 44 minutes, and 30 seconds spent in the parking orbit. This was followed by a trans-lunar injection (TLI) burn of the S-IVB third stage for 318 seconds, accelerating
680-624: A service module (SM) to provide the command module with propulsion, electrical power, oxygen, and water; and a two-stage lunar module (LM), which comprised a descent stage for landing on the Moon and an ascent stage to return the astronauts to lunar orbit. This configuration could be launched by the Saturn V rocket that was then under development. The initial crew assignment of Frank Borman as Commander, Michael Collins as Command Module Pilot (CMP) and William Anders as Lunar Module Pilot (LMP) for
816-555: A sextant built into the spacecraft, measuring the angle between a star and the Earth's (or the Moon's) horizon . This task was made difficult by a large cloud of debris around the spacecraft, which made it hard to distinguish the stars. By seven hours into the mission, the crew was about 1 hour and 40 minutes behind flight plan because of the problems in moving away from the S-IVB and Lovell's obscured star sightings. The crew placed
952-773: A 130-million-cubic-foot (3,700,000 m ) Vertical Assembly Building (VAB). in which the space vehicle (launch vehicle and spacecraft) would be assembled on a mobile launcher platform and then moved by a crawler-transporter to one of several launch pads. Although at least three pads were planned, only two, designated A and B, were completed in October 1965. The LOC also included an Operations and Checkout Building (OCB) to which Gemini and Apollo spacecraft were initially received prior to being mated to their launch vehicles. The Apollo spacecraft could be tested in two vacuum chambers capable of simulating atmospheric pressure at altitudes up to 250,000 feet (76 km), which
1088-473: A CSM-only mission could be flown in December 1968. Instead of repeating the "C" mission flight of Apollo 7, this CSM could be sent all the way to the Moon, with the possibility of entering a lunar orbit and returning to Earth. The new mission would also allow NASA to test lunar landing procedures that would otherwise have had to wait until Apollo 10 , the scheduled "F" mission. This also meant that
1224-470: A commitment on America's response to the Soviets. On April 20, Kennedy sent a memo to Vice President Lyndon B. Johnson , asking Johnson to look into the status of America's space program, and into programs that could offer NASA the opportunity to catch up. Johnson responded approximately one week later, concluding that "we are neither making maximum effort nor achieving results necessary if this country
1360-525: A crewed mission until additional uncrewed test flights proved the Saturn V was ready. Teams from the MSFC went to work on the problems. Of primary concern was the pogo oscillation, which would not only hamper engine performance, but could exert significant g-forces on a crew. A task force of contractors, NASA agency representatives, and MSFC researchers concluded that the engines vibrated at a frequency similar to
1496-460: A flight director. The directors for Apollo 8 were Clifford E. Charlesworth (Green team), Glynn Lunney (Black team), and Milton Windler (Maroon team). The triangular shape of the insignia refers to the shape of the Apollo CM. It shows a red figure 8 looping around the Earth and Moon to reflect both the mission number and the circumlunar nature of the mission. On the bottom of
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#17327880981601632-460: A gauge to judge and monitor the three industry designs. In November 1960, John F. Kennedy was elected president after a campaign that promised American superiority over the Soviet Union in the fields of space exploration and missile defense . Up to the election of 1960, Kennedy had been speaking out against the " missile gap " that he and many other senators said had developed between
1768-549: A globe and from that calculated the fuel needed for the flight. The total he had carried was a tenth of the amount that the Saturn V would burn every second. The next day, the Lindberghs watched the launch of Apollo 8 from a nearby dune. The Saturn V rocket used by Apollo 8 was designated AS-503, or the "03rd" model of the Saturn V ("5") rocket to be used in the Apollo-Saturn ("AS") program. When it
1904-454: A great deal of time preparing to test the LM, and that was what he still wanted to do. Slayton then decided to swap the prime and backup crews of the D and E missions. This swap also meant a swap of spacecraft, requiring Borman's crew to use CSM-103, while McDivitt's crew would use CSM-104, since CM-104 could not be made ready by December. David Scott was not happy about giving up CM-103,
2040-440: A great new American enterprise—time for this nation to take a clearly leading role in space achievement, which in many ways may hold the key to our future on Earth. ... I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth. No single space project in this period will be more impressive to mankind, or more important in
2176-462: A limited Earth orbital mission, Apollo would carry three. Possible missions included ferrying crews to a space station , circumlunar flights , and eventual crewed lunar landings . In July 1960, NASA Deputy Administrator Hugh L. Dryden announced the Apollo program to industry representatives at a series of Space Task Group conferences. Preliminary specifications were laid out for a spacecraft with
2312-402: A major setback in 1967 when an Apollo 1 cabin fire killed the entire crew during a prelaunch test. After the first successful landing, sufficient flight hardware remained for nine follow-on landings with a plan for extended lunar geological and astrophysical exploration. Budget cuts forced the cancellation of three of these. Five of the remaining six missions achieved successful landings, but
2448-521: A maximum distance from Earth of 203,752 nautical miles (234,474 statute miles; 377,349 kilometers). Apollo 8 was launched at 12:51:00 UTC (07:51:00 Eastern Standard Time ) on December 21, 1968, using the Saturn V's three stages to achieve Earth orbit. The S-IC first stage landed in the Atlantic Ocean at 30°12′N 74°7′W / 30.200°N 74.117°W / 30.200; -74.117 ( Apollo 8 S-IC impact ) , and
2584-402: A mockup N1 being rolled to the pad at Baikonur on November 25, 1967. The Apollo 8 crew, now living in the crew quarters at Kennedy Space Center, received a visit from Charles Lindbergh and his wife, Anne Morrow Lindbergh , the night before the launch. They talked about how, before his 1927 flight , Lindbergh had used a piece of string to measure the distance from New York City to Paris on
2720-477: A prime and a backup crew. For Apollo, a third crew of astronauts was added, known as the support crew. The support crew maintained the flight plan, checklists, and mission ground rules, and ensured that the prime and backup crews were apprised of any changes. The support crew developed procedures in the simulators, especially those for emergency situations, so that the prime and backup crews could practice and master them in their simulator training. For Apollo 8,
2856-439: A project: to land a man on the Moon and return him to the Earth. This project already had a name: Project Apollo . An early and crucial decision was the adoption of lunar orbit rendezvous , under which a specialized spacecraft would land on the lunar surface. The Apollo spacecraft therefore had three primary components: a command module (CM) with a cabin for the three astronauts, and the only part that would return to Earth;
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#17327880981602992-408: A radiation dosage of no more than a chest X-ray , or 1 milligray (mGy; during a year, the average human receives a dose of 2 to 3 mGy from background radiation ). To record the actual radiation dosages, each crew member wore a Personal Radiation Dosimeter that transmitted data to Earth, as well as three passive film dosimeters that showed the cumulative radiation experienced by
3128-404: A reaction control system. The initial LM model weighed approximately 33,300 pounds (15,100 kg), and allowed surface stays up to around 34 hours. An extended lunar module (ELM) weighed over 36,200 pounds (16,400 kg), and allowed surface stays of more than three days. The contract for design and construction of the lunar module was awarded to Grumman Aircraft Engineering Corporation , and
3264-500: A separation maneuver. Mission Control first suggested pointing the spacecraft towards Earth and using the small reaction control system (RCS) thrusters on the service module (SM) to add 1.1 ft/s (0.34 m/s) to their velocity away from the Earth, but Borman did not want to lose sight of the S-IVB. After discussion, the crew and Mission Control decided to burn in the Earth direction to increase speed, but at 7.7 ft/s (2.3 m/s) instead. The time needed to prepare and perform
3400-558: A spacecraft that could meet it while minimizing risk to human life, limiting cost, and not exceeding limits in possible technology and astronaut skill. Four possible mission modes were considered: In early 1961, direct ascent was generally the mission mode in favor at NASA. Many engineers feared that rendezvous and docking, maneuvers that had not been attempted in Earth orbit , would be nearly impossible in lunar orbit . LOR advocates including John Houbolt at Langley Research Center emphasized
3536-493: A speed of 3,990 ft/s (1,220 m/s) relative to the Moon. This historic moment was of little interest to the crew, since they were still calculating their trajectory with respect to the launch pad at Kennedy Space Center. They would continue to do so until they performed their last mid-course correction, switching to a reference frame based on ideal orientation for the second engine burn they would make in lunar orbit. The last major event before Lunar Orbit Insertion (LOI)
3672-427: A television broadcast at 31 hours after launch. The Apollo 8 crew used a 2-kilogram (4.4 lb) camera that broadcast in black-and-white only, using a Vidicon tube. The camera had two lenses , a very wide-angle (160°) lens , and a telephoto (9°) lens . During this first broadcast, the crew gave a tour of the spacecraft and attempted to show how the Earth appeared from space. However, difficulties aiming
3808-508: Is nearly a vacuum. Administrator Webb realized that in order to keep Apollo costs under control, he had to develop greater project management skills in his organization, so he recruited George E. Mueller for a high management job. Mueller accepted, on the condition that he have a say in NASA reorganization necessary to effectively administer Apollo. Webb then worked with Associate Administrator (later Deputy Administrator) Seamans to reorganize
3944-535: Is to reach a position of leadership." His memo concluded that a crewed Moon landing was far enough in the future that it was likely the United States would achieve it first. On May 25, 1961, twenty days after the first US crewed spaceflight Freedom 7 , Kennedy proposed the crewed Moon landing in a Special Message to the Congress on Urgent National Needs : Now it is time to take longer strides—time for
4080-497: The Apollo 13 landing had to be aborted after an oxygen tank exploded en route to the Moon, crippling the CSM. The crew barely managed a safe return to Earth by using the lunar module as a "lifeboat" on the return journey. Apollo used the Saturn family of rockets as launch vehicles, which were also used for an Apollo Applications Program , which consisted of Skylab , a space station that supported three crewed missions in 1973–1974, and
4216-616: The Apollo command and service module , succeeding the Mercury program . A lunar landing became the focus of the program only in 1961. Thereafter Project Gemini instead followed the Mercury program to test and study advanced crewed spaceflight technology. The Apollo program was conceived during the Eisenhower administration in early 1960, as a follow-up to Project Mercury. While the Mercury capsule could support only one astronaut on
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4352-568: The Apollo–Soyuz Test Project, a joint United States - Soviet Union low Earth orbit mission in 1975. Apollo set several major human spaceflight milestones . It stands alone in sending crewed missions beyond low Earth orbit . Apollo 8 was the first crewed spacecraft to orbit another celestial body, and Apollo 11 was the first crewed spacecraft to land humans on one. Overall, the Apollo program returned 842 pounds (382 kg) of lunar rocks and soil to Earth, greatly contributing to
4488-488: The National Aeronautics and Space Administration (NASA), which succeeded in preparing and landing the first men on the Moon in 1969. It was first conceived in 1960 during President Dwight D. Eisenhower's administration as a three-person spacecraft to follow the one-person Project Mercury , which put the first Americans in space. Apollo was later dedicated to President John F. Kennedy 's national goal for
4624-531: The S-II second stage landed at 31°50′N 37°17′W / 31.833°N 37.283°W / 31.833; -37.283 ( Apollo 8 S-II impact ) . The S-IVB third stage injected the craft into Earth orbit and remained attached to perform the TLI burn that would put the spacecraft on a trajectory to the Moon. Once the vehicle reached Earth orbit, both the crew and Houston flight controllers spent
4760-473: The SPS ." Ironically, just such a failure happened on Apollo 13 when an oxygen tank explosion left the CSM without electrical power. The lunar module provided propulsion, electrical power and life support to get the crew home safely. Faget's preliminary Apollo design employed a cone-shaped command module, supported by one of several service modules providing propulsion and electrical power, sized appropriately for
4896-488: The Saturn V launch vehicle and LOR by forcing Shea, Seamans, and even Webb to defend themselves, delaying its formal announcement to the press on July 11, 1962, and forcing Webb to still hedge the decision as "tentative". Wiesner kept up the pressure, even making the disagreement public during a two-day September visit by the President to Marshall Space Flight Center . Wiesner blurted out "No, that's no good" in front of
5032-425: The Soviet Union 's Zond 5 mission, which flew some living creatures, including Russian tortoises , in a cislunar loop around the Moon and returned them to Earth on September 21. There was speculation within NASA and the press that they might be preparing to launch cosmonauts on a similar circumlunar mission before the end of 1968. Compounding these concerns, American reconnaissance satellites observed
5168-588: The Sputnik crisis and triggered the Space Race . President John F. Kennedy believed that not only was it in the national interest of the United States to be superior to other nations, but that the perception of American power was at least as important as the actuality. It was therefore intolerable to him for the Soviet Union to be more advanced in the field of space exploration. He was determined that
5304-526: The U.S. Air Force , so he got Webb's permission to recruit General Samuel C. Phillips , who gained a reputation for his effective management of the Minuteman program, as OMSF program controller. Phillips's superior officer Bernard A. Schriever agreed to loan Phillips to NASA, along with a staff of officers under him, on the condition that Phillips be made Apollo Program Director. Mueller agreed, and Phillips managed Apollo from January 1964, until it achieved
5440-737: The White Sands Missile Range between May 1964 and January 1966. Saturn I, the first US heavy lift launch vehicle, was initially planned to launch partially equipped CSMs in low Earth orbit tests. The S-I first stage burned RP-1 with liquid oxygen (LOX) oxidizer in eight clustered Rocketdyne H-1 engines, to produce 1,500,000 pounds-force (6,670 kN) of thrust. The S-IV second stage used six liquid hydrogen-fueled Pratt & Whitney RL-10 engines with 90,000 pounds-force (400 kN) of thrust. The S-V third stage flew inactively on Saturn I four times. The first four Saturn I test flights were launched from LC-34, with only
5576-512: The heat shield to crack and propellant lines to burst. Because it was impossible to get a perfect roll, the spacecraft swept out a cone as it rotated. The crew had to make minor adjustments every half hour as the cone pattern got larger and larger. The first mid-course correction came eleven hours into the flight. The crew had been awake for more than 16 hours. Before launch, NASA had decided at least one crew member should be awake at all times to deal with problems that might arise. Borman started
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5712-453: The lunar surface . At 64 hours into the flight, the crew began to prepare for Lunar Orbit Insertion 1 (LOI-1). This maneuver had to be performed perfectly, and due to orbital mechanics had to be on the far side of the Moon, out of contact with the Earth. After Mission Control was polled for a " go/no go " decision, the crew was told at 68 hours that they were Go and "riding the best bird we can find". Lovell replied, "We'll see you on
5848-450: The "5" indicating Saturn V. The three-stage Saturn V was designed to send a fully fueled CSM and LM to the Moon. It was 33 feet (10.1 m) in diameter and stood 363 feet (110.6 m) tall with its 96,800-pound (43,900 kg) lunar payload. Its capability grew to 103,600 pounds (47,000 kg) for the later advanced lunar landings. The S-IC first stage burned RP-1/LOX for a rated thrust of 7,500,000 pounds-force (33,400 kN), which
5984-410: The "D" mission, a test of the LM in a low Earth orbit in December 1968 by James McDivitt , David Scott , and Russell Schweickart , while Borman's crew would fly the "E" mission, a more rigorous LM test in an elliptical medium Earth orbit as Apollo 9, in early 1969. The "F" Mission would test the CSM and LM in lunar orbit, and the "G" mission would be the finale, the Moon landing. Production of
6120-428: The 8 are the names of the three astronauts. The initial design of the insignia was developed by Jim Lovell, who reportedly sketched it while riding in the back seat of a T-38 flight from California to Houston shortly after learning of Apollo 8's re-designation as a lunar-orbital mission. The crew wanted to name their spacecraft, but NASA did not allow it. The crew would have likely chosen Columbiad ,
6256-478: The 1960s of "landing a man on the Moon and returning him safely to the Earth" in an address to Congress on May 25, 1961. It was the third US human spaceflight program to fly, preceded by the two-person Project Gemini conceived in 1961 to extend spaceflight capability in support of Apollo. Kennedy's goal was accomplished on the Apollo 11 mission when astronauts Neil Armstrong and Buzz Aldrin landed their Apollo Lunar Module (LM) on July 20, 1969, and walked on
6392-451: The 1960s, President Kennedy's target date. The LOR method had the advantage of allowing the lander spacecraft to be used as a "lifeboat" in the event of a failure of the command ship. Some documents prove this theory was discussed before and after the method was chosen. In 1964 an MSC study concluded, "The LM [as lifeboat] ... was finally dropped, because no single reasonable CSM failure could be identified that would prohibit use of
6528-531: The 63,650 lb (28,870 kg) command and service module and 19,900 lb (9,000 kg) LM test article from an orbital velocity of 25,567 feet per second (7,793 m/s) to the injection velocity of 35,505 ft/s (10,822 m/s) which set a record for the highest speed, relative to Earth, that humans had ever traveled. This speed was slightly less than the Earth's escape velocity of 36,747 feet per second (11,200 m/s), but put Apollo 8 into an elongated elliptical Earth orbit, close enough to
6664-523: The CSM's role to the translunar ferry used to transport the crew, along with a new spacecraft, the Lunar Excursion Module (LEM, later shortened to LM (Lunar Module) but still pronounced / ˈ l ɛ m / ) which would take two individuals to the lunar surface and return them to the CSM. The command module (CM) was the conical crew cabin, designed to carry three astronauts from launch to lunar orbit and back to an Earth ocean landing. It
6800-630: The Canaveral launch facilities in Florida . The two newest launch complexes were already being built for the Saturn I and IB rockets at the northernmost end: LC-34 and LC-37 . But an even bigger facility would be needed for the mammoth rocket required for the crewed lunar mission, so land acquisition was started in July 1961 for a Launch Operations Center (LOC) immediately north of Canaveral at Merritt Island . The design, development and construction of
6936-606: The Data Storage Equipment (DSE), which could tape voice recordings and telemetry and dump them to Mission Control at high speed. After recording a description of Borman's illness they asked Mission Control to check the recording, stating that they "would like an evaluation of the voice comments". The Apollo 8 crew and Mission Control medical personnel held a conference using an unoccupied second-floor control room (there were two identical control rooms in Houston, on
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#17327880981607072-430: The Earth's atmosphere or return to Earth, its fuselage was designed totally without aerodynamic considerations and was of an extremely lightweight construction. It consisted of separate descent and ascent stages, each with its own engine. The descent stage contained storage for the descent propellant, surface stay consumables, and surface exploration equipment. The ascent stage contained the crew cabin, ascent propellant, and
7208-531: The Earth's equatorial plane, and an orbital period of 340.80 days. It became a derelict object , and will continue to orbit the Sun for many years, if not retrieved. The Apollo 8 crew were the first humans to pass through the Van Allen radiation belts , which extend up to 15,000 miles (24,000 km) from Earth. Scientists predicted that passing through the belts quickly at the spacecraft's high speed would cause
7344-515: The Earth, Gilruth had moved his organization to rented space in Houston, and construction of the MSC facility was under way, Kennedy visited Rice to reiterate his challenge in a famous speech : But why, some say, the Moon? Why choose this as our goal? And they may well ask, why climb the highest mountain ? Why, 35 years ago, fly the Atlantic ? ... We choose to go to the Moon. We choose to go to
7480-623: The LM fell behind schedule, and when Apollo 8's LM-3 arrived at the Kennedy Space Center (KSC) in June 1968, more than a hundred significant defects were discovered, leading Bob Gilruth , the director of the Manned Spacecraft Center (MSC), and others to conclude that there was no prospect of LM-3 being ready to fly in 1968. Indeed, it was possible that delivery would slip to February or March 1969. Following
7616-443: The MSFC. A Saturn stage IC was equipped with shock-absorbing devices to demonstrate the team's solution to the problem of pogo oscillation, while a Saturn Stage II was retrofitted with modified fuel lines to demonstrate their resistance to leaks and ruptures in vacuum conditions. Once NASA administrators were convinced that the problems had been solved, they gave their approval for a crewed mission using AS-503. The Apollo 8 spacecraft
7752-613: The Moon by the end of 1969 required the most sudden burst of technological creativity, and the largest commitment of resources ($ 25 billion; $ 182 billion in 2023 US dollars) ever made by any nation in peacetime. At its peak, the Apollo program employed 400,000 people and required the support of over 20,000 industrial firms and universities. On July 1, 1960, NASA established the Marshall Space Flight Center (MSFC) in Huntsville, Alabama . MSFC designed
7888-436: The Moon for much of the outward cruise. Two factors made the Moon almost impossible to see from inside the spacecraft: three of the five windows fogging up due to out-gassed oils from the silicone sealant , and the attitude required for passive thermal control. It was not until the crew had gone behind the Moon that they would be able to see it for the first time. Apollo 8 made a second television broadcast at 55 hours into
8024-628: The Moon in this decade and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills; because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win ... The MSC was completed in September 1963. It was renamed by the US Congress in honor of Lyndon Johnson soon after his death in 1973. It also became clear that Apollo would outgrow
8160-405: The Moon to be captured by the Moon's gravity. The standard lunar orbit for Apollo missions was planned as a nominal 60-nautical-mile (110 km) circular orbit above the Moon's surface. Initial lunar orbit insertion was an ellipse with a perilune of 60.0 nautical miles (111.1 km) and an apolune of 168.5 nautical miles (312.1 km), at an inclination of 12° from the lunar equator. This
8296-399: The Moon. The S-IVB engine ignited on time and performed the TLI burn perfectly. Over the next five minutes, the spacecraft's speed increased from 7,600 to 10,800 meters per second (25,000 to 35,000 ft/s). After the S-IVB had placed the mission on course for the Moon, the command and service modules (CSM), the remaining Apollo 8 spacecraft, separated from it. The crew then rotated
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#17327880981608432-591: The October Cuban Missile Crisis , and fear of Kennedy's support for Webb. NASA announced the selection of Grumman as the LEM contractor in November 1962. Space historian James Hansen concludes that: Without NASA's adoption of this stubbornly held minority opinion in 1962, the United States may still have reached the Moon, but almost certainly it would not have been accomplished by the end of
8568-815: The Office of Manned Space Flight (OMSF). On July 23, 1963, Webb announced Mueller's appointment as Deputy Associate Administrator for Manned Space Flight, to replace then Associate Administrator D. Brainerd Holmes on his retirement effective September 1. Under Webb's reorganization, the directors of the Manned Spacecraft Center ( Gilruth ), Marshall Space Flight Center ( von Braun ), and the Launch Operations Center ( Debus ) reported to Mueller. Based on his industry experience on Air Force missile projects, Mueller realized some skilled managers could be found among high-ranking officers in
8704-454: The Saturn V. The Saturn IB could send over 40,000 pounds (18,100 kg) into low Earth orbit, sufficient for a partially fueled CSM or the LM. Saturn IB launch vehicles and flights were designated with an AS-200 series number, "AS" indicating "Apollo Saturn" and the "2" indicating the second member of the Saturn rocket family. Saturn V launch vehicles and flights were designated with an AS-500 series number, "AS" indicating "Apollo Saturn" and
8840-457: The Soviet Union and the United States due to the inaction of President Eisenhower. Beyond military power, Kennedy used aerospace technology as a symbol of national prestige, pledging to make the US not "first but, first and, first if, but first period". Despite Kennedy's rhetoric, he did not immediately come to a decision on the status of the Apollo program once he became president. He knew little about
8976-594: The United States Apollo space program (the first, Apollo 7 , stayed in Earth orbit). Apollo 8 was the third flight and the first crewed launch of the Saturn V rocket. It was the first human spaceflight from the Kennedy Space Center , adjacent to Cape Kennedy Air Force Station in Florida. Originally planned as the second crewed Apollo Lunar Module and command module test, to be flown in an elliptical medium Earth orbit in early 1969,
9112-512: The United States should compete, and sought a challenge that maximized its chances of winning. The Soviet Union had heavier-lifting carrier rockets , which meant Kennedy needed to choose a goal that was beyond the capacity of the existing generation of rocketry, one where the US and Soviet Union would be starting from a position of equality—something spectacular, even if it could not be justified on military, economic, or scientific grounds. After consulting with his experts and advisors, he chose such
9248-433: The additional burn put the crew an hour behind their onboard tasks. Five hours after launch, Mission Control sent a command to the S-IVB to vent its remaining fuel, changing its trajectory. The S-IVB, with the test article attached, posed no further hazard to Apollo 8, passing the orbit of the Moon and going into a 0.99-by-0.92- astronomical-unit (148 by 138 Gm ) solar orbit with an inclination of 23.47° from
9384-472: The center was conducted by Kurt H. Debus , a member of Wernher von Braun 's original V-2 rocket engineering team. Debus was named the LOC's first Director. Construction began in November 1962. Following Kennedy's death , President Johnson issued an executive order on November 29, 1963, to rename the LOC and Cape Canaveral in honor of Kennedy. The LOC included Launch Complex 39 , a Launch Control Center , and
9520-426: The clear goal of a crewed landing replacing the more nebulous goals of space stations and circumlunar flights, NASA decided that, in order to make progress quickly, it would discard the feasibility study designs of Convair, GE, and Martin, and proceed with Faget's command and service module design. The mission module was determined to be useful only as an extra room, and therefore unnecessary. They used Faget's design as
9656-412: The command and service module (CSM) in Earth orbit. Apollo 5 was a "B" mission, a test of the LM in Earth orbit. Apollo 7, scheduled for October 1968, would be a "C" mission, a crewed Earth-orbit flight of the CSM. Further missions depended on the readiness of the LM. It had been decided as early as May 1967 that there would be at least four additional missions. Apollo 8 was planned as
9792-449: The contract to build the CSM, and also the second stage of the Saturn V launch vehicle for NASA. Because the CSM design was started early before the selection of lunar orbit rendezvous, the service propulsion engine was sized to lift the CSM off the Moon, and thus was oversized to about twice the thrust required for translunar flight. Also, there was no provision for docking with the lunar module. A 1964 program definition study concluded that
9928-437: The crew. By the end of the mission, the crew members experienced an average radiation dose of 1.6 mGy. Lovell's main job as Command Module Pilot was as navigator . Although Mission Control normally performed all the navigation calculations, it was necessary to have a crew member adept at navigation so that the crew could return to Earth in case communication with Mission Control was lost. Lovell navigated by star sightings using
10064-498: The direction of travel). This change was less than the planned 24.8 ft/s (7.6 m/s), because of a bubble of helium in the oxidizer lines, which caused unexpectedly low propellant pressure. The crew had to use the small RCS thrusters to make up the shortfall. Two later planned mid-course corrections were canceled because the Apollo 8 trajectory was found to be perfect. About an hour after starting his sleep shift, Borman obtained permission from ground control to take
10200-451: The first human spaceflight to reach the Moon . The crew orbited the Moon ten times without landing and then returned to Earth . The three astronauts — Frank Borman , James Lovell , and William Anders —were the first humans to see and photograph the far side of the Moon and an Earthrise . Apollo 8 launched on December 21, 1968, and was the second crewed spaceflight mission flown in
10336-487: The first case of a commander of a previous mission (Lovell, Gemini XII) flying as a non-commander. This was also the first mission to reunite crewmates from a previous mission (Lovell and Borman, Gemini VII). As of June 2024, James Lovell is the last surviving Apollo 8 astronaut. Frank Borman and William Anders died on November 7, 2023, and on June 7, 2024, respectively. The backup crew assignment of Neil Armstrong as Commander, Lovell as CMP, and Buzz Aldrin as LMP for
10472-463: The first human landing in July 1969, after which he returned to Air Force duty. Charles Fishman, in One Giant Leap , estimated the number of people and organizations involved into the Apollo program as "410,000 men and women at some 20,000 different companies contributed to the effort". Once Kennedy had defined a goal, the Apollo mission planners were faced with the challenge of designing
10608-485: The first person to fly in space, reinforcing American fears about being left behind in a technological competition with the Soviet Union. At a meeting of the US House Committee on Science and Astronautics one day after Gagarin's flight, many congressmen pledged their support for a crash program aimed at ensuring that America would catch up. Kennedy was circumspect in his response to the news, refusing to make
10744-465: The first sleep shift but found sleeping difficult because of the constant radio chatter and mechanical noises. Testing on the ground had shown that the service propulsion system (SPS) engine had a small chance of exploding when burned for long periods unless its combustion chamber was "coated" first by burning the engine for a short period. This first correction burn was only 2.4 seconds and added about 20.4 ft/s (6.2 m/s) velocity prograde (in
10880-421: The first stage live, carrying dummy upper stages filled with water. The first flight with a live S-IV was launched from LC-37. This was followed by five launches of boilerplate CSMs (designated AS-101 through AS-105 ) into orbit in 1964 and 1965. The last three of these further supported the Apollo program by also carrying Pegasus satellites, which verified the safety of the translunar environment by measuring
11016-400: The flight, and 13 hours before entering lunar orbit, the crew of Apollo 8 became the first humans to enter the gravitational sphere of influence of another celestial body. In other words, the effect of the Moon's gravitational force on Apollo 8 became stronger than that of the Earth. At the time it happened, Apollo 8 was 38,759 miles (62,377 km) from the Moon and had
11152-490: The flight. This time, the crew rigged up filters meant for the still cameras so they could acquire images of the Earth through the telephoto lens. Although difficult to aim, as they had to maneuver the entire spacecraft, the crew was able to broadcast back to Earth the first television pictures of the Earth. The crew spent the transmission describing the Earth, what was visible, and the colors they could see. The transmission lasted 23 minutes. At about 55 hours and 40 minutes into
11288-445: The frequency and severity of micrometeorite impacts. In September 1962, NASA planned to launch four crewed CSM flights on the Saturn I from late 1965 through 1966, concurrent with Project Gemini. The 22,500-pound (10,200 kg) payload capacity would have severely limited the systems which could be included, so the decision was made in October 1963 to use the uprated Saturn IB for all crewed Earth orbital flights. The Saturn IB
11424-463: The frequency at which the spacecraft itself vibrated, causing a resonance effect that induced oscillations in the rocket. A system that used helium gas to absorb some of these vibrations was installed. Of equal importance was the failure of three engines during flight. Researchers quickly determined that a leaking hydrogen fuel line ruptured when exposed to vacuum, causing a loss of fuel pressure in engine two. When an automatic shutoff attempted to close
11560-432: The heavy lift-class Saturn launch vehicles , which would be required for Apollo. It became clear that managing the Apollo program would exceed the capabilities of Robert R. Gilruth 's Space Task Group , which had been directing the nation's crewed space program from NASA's Langley Research Center . So Gilruth was given authority to grow his organization into a new NASA center, the Manned Spacecraft Center (MSC). A site
11696-488: The important weight reductions that were offered by the LOR approach. Throughout 1960 and 1961, Houbolt campaigned for the recognition of LOR as a viable and practical option. Bypassing the NASA hierarchy, he sent a series of memos and reports on the issue to Associate Administrator Robert Seamans; while acknowledging that he spoke "somewhat as a voice in the wilderness", Houbolt pleaded that LOR should not be discounted in studies of
11832-496: The initial design should be continued as Block I which would be used for early testing, while Block II, the actual lunar spacecraft, would incorporate the docking equipment and take advantage of the lessons learned in Block I development. The Apollo Lunar Module (LM) was designed to descend from lunar orbit to land two astronauts on the Moon and take them back to orbit to rendezvous with the command module. Not designed to fly through
11968-449: The instruments told them that they were 192 miles from their projected landing site, and were precisely 50,174 radar~measured feet above the long shadows of the moon, they would unleash decelerating thrust and begin slowing their speed for the touchdown.....this was it. PDI. Powered Descent Initiate." Apollo program The Apollo program , also known as Project Apollo , was the United States human spaceflight program carried out by
12104-584: The late 1950s and early 1960s, the United States was engaged in the Cold War , a geopolitical rivalry with the Soviet Union . On October 4, 1957, the Soviet Union launched Sputnik 1 , the first artificial satellite . This unexpected success stoked fears and imaginations around the world. It not only demonstrated that the Soviet Union had the capability to deliver nuclear weapons over intercontinental distances, it challenged American claims of military, economic, and technological superiority. The launch precipitated
12240-530: The liquid hydrogen valve and shut down engine two, it had accidentally shut down engine three's liquid oxygen due to a miswired connection. As a result, engine three failed within one second of engine two's shutdown. Further investigation revealed the same problem for the third-stage engine—a faulty igniter line. The team modified the igniter lines and fuel conduits, hoping to avoid similar problems on future launches. The teams tested their solutions in August 1968 at
12376-450: The long-range exploration of space; and none will be so difficult or expensive to accomplish. At the time of Kennedy's proposal, only one American had flown in space—less than a month earlier—and NASA had not yet sent an astronaut into orbit. Even some NASA employees doubted whether Kennedy's ambitious goal could be met. By 1963, Kennedy even came close to agreeing to a joint US-USSR Moon mission, to eliminate duplication of effort. With
12512-510: The lunar flights. On the extended lunar missions, an orbital scientific instrument package was carried. The service module was discarded just before reentry. The module was 24.6 feet (7.5 m) long and 12.83 feet (3.91 m) in diameter. The initial lunar flight version weighed approximately 51,300 pounds (23,300 kg) fully fueled, while a later version designed to carry a lunar orbit scientific instrument package weighed just over 54,000 pounds (24,000 kg). North American Aviation won
12648-503: The lunar surface, while Michael Collins remained in lunar orbit in the command and service module (CSM), and all three landed safely on Earth in the Pacific Ocean on July 24. Five subsequent Apollo missions also landed astronauts on the Moon, the last, Apollo 17 , in December 1972. In these six spaceflights, twelve people walked on the Moon . Apollo ran from 1961 to 1972, with the first crewed flight in 1968. It encountered
12784-701: The medium Earth orbit "E" mission could be dispensed with. The net result was that only the "D" mission had to be delayed, and the plan for lunar landing in mid-1969 could remain on timeline. On August 9, 1968, Low discussed the idea with Gilruth, Flight Director Chris Kraft , and the Director of Flight Crew Operations, Donald Slayton . They then flew to the Marshall Space Flight Center (MSFC) in Huntsville, Alabama , where they met with KSC Director Kurt Debus , Apollo Program Director Samuel C. Phillips , Rocco Petrone , and Wernher von Braun . Jerry Wittenstein, deputy chief of flight mechanics, presented trajectories for
12920-539: The mission profile was changed in August 1968 to a more ambitious command-module-only lunar orbital flight to be flown in December, as the lunar module was not yet ready to make its first flight. Astronaut Jim McDivitt 's crew, who were training to fly the first lunar module flight in low Earth orbit, became the crew for the Apollo 9 mission, and Borman's crew were moved to the Apollo 8 mission. This left Borman's crew with two to three months' less training and preparation time than originally planned, and replaced
13056-520: The name of the giant cannon that launches a space vehicle in Jules Verne 's 1865 novel From the Earth to the Moon . The Apollo 11 CM was named Columbia in part for that reason. On September 20, 1967, NASA adopted a seven-step plan for Apollo missions, with the final step being a Moon landing. Apollo 4 and Apollo 6 were "A" missions, tests of the Saturn V launch vehicle using an uncrewed Block I production model of
13192-411: The narrow-angle lens without the aid of a monitor to show what it was looking at made showing the Earth impossible. Additionally, without proper filters , the Earth image became saturated by any bright source. In the end, all the crew could show the people watching back on Earth was a bright blob. After broadcasting for 17 minutes, the rotation of the spacecraft took the high-gain antenna out of view of
13328-402: The new mission. Kraft considered the proposal feasible from a flight control standpoint; Debus and Petrone agreed that the next Saturn V, AS-503, could be made ready by December 1; and von Braun was confident the pogo oscillation problems that had afflicted Apollo 6 had been fixed. Almost every senior manager at NASA agreed with this new mission, citing confidence in both the hardware and
13464-518: The next 2 hours and 38 minutes checking that the spacecraft was in proper working order and ready for TLI. The proper operation of the S-IVB third stage of the rocket was crucial, and in the last uncrewed test, it had failed to reignite for this burn. Collins was the first CAPCOM on duty, and at 2 hours, 27 minutes and 22 seconds after launch he radioed, "Apollo 8. You are Go for TLI." This communication meant that Mission Control had given official permission for Apollo 8 to go to
13600-548: The original seven-step plan would have meant delaying the "D" and subsequent missions, and endangering the program's goal of a lunar landing before the end of 1969. George Low , the Manager of the Apollo Spacecraft Program Office, proposed a solution in August 1968 to keep the program on track despite the LM delay. Since the next CSM (designated as "CSM-103") would be ready three months before LM-3,
13736-413: The other side", and for the first time in history, humans travelled behind the Moon and out of radio contact with the Earth. Frances "Poppy" Northcutt , who was the first woman in NASA's mission control and helped calculate the return to Earth trajectory for this mission, recounts what it was like when Apollo 8 went behind the Moon for the first time in an interview: "That was a very nerve-racking period on
13872-496: The personnel, along with the potential for a circumlunar flight providing a significant morale boost. The only person who needed some convincing was James E. Webb , the NASA administrator. Backed by the full support of his agency, Webb authorized the mission. Apollo 8 was officially changed from a "D" mission to a "C-Prime" lunar-orbit mission. With the change in mission for Apollo 8, Slayton asked McDivitt if he still wanted to fly it. McDivitt turned it down; his crew had spent
14008-474: The planned lunar module training with translunar navigation training. Apollo 8 took 68 hours to travel to the Moon. The crew orbited the Moon ten times over the course of twenty hours, during which they made a Christmas Eve television broadcast where they read the first ten verses from the Book of Genesis . At the time, the broadcast was the most watched TV program ever. Apollo 8's successful mission paved
14144-483: The press, during a presentation by von Braun. Webb jumped in and defended von Braun, until Kennedy ended the squabble by stating that the matter was "still subject to final review". Webb held firm and issued a request for proposal to candidate Lunar Excursion Module (LEM) contractors. Wiesner finally relented, unwilling to settle the dispute once and for all in Kennedy's office, because of the President's involvement with
14280-556: The project was overseen by Thomas J. Kelly . Before the Apollo program began, Wernher von Braun and his team of rocket engineers had started work on plans for very large launch vehicles, the Saturn series , and the even larger Nova series. In the midst of these plans, von Braun was transferred from the Army to NASA and was made Director of the Marshall Space Flight Center. The initial direct ascent plan to send
14416-519: The question. Seamans's establishment of an ad hoc committee headed by his special technical assistant Nicholas E. Golovin in July 1961, to recommend a launch vehicle to be used in the Apollo program, represented a turning point in NASA's mission mode decision. This committee recognized that the chosen mode was an important part of the launch vehicle choice, and recommended in favor of a hybrid EOR-LOR mode. Its consideration of LOR—as well as Houbolt's ceaseless work—played an important role in publicizing
14552-415: The receiving stations on Earth and they ended the transmission with Lovell wishing his mother a happy birthday. By this time, the crew had completely abandoned the planned sleep shifts. Lovell went to sleep 32 + 1 ⁄ 2 hours into the flight – three-and-a-half hours before he had planned to. A short while later, Anders also went to sleep after taking a sleeping pill. The crew was unable to see
14688-438: The scheduled launch. As the first crewed spacecraft to orbit more than one celestial body, Apollo 8's profile had two different sets of orbital parameters, separated by a translunar injection maneuver. Apollo lunar missions would begin with a nominal 100-nautical-mile (185.2 km) circular Earth parking orbit. Apollo 8 was launched into an initial orbit with an apogee of 99.99 nautical miles (185.18 km) and
14824-613: The second and third floors, only one of which was used during a mission). The conference participants concluded that there was little to worry about and that Borman's illness was either a 24-hour flu , as Borman thought, or a reaction to the sleeping pill. Researchers now believe that he was suffering from space adaptation syndrome , which affects about a third of astronauts during their first day in space as their vestibular system adapts to weightlessness . Space adaptation syndrome had not occurred on previous spacecraft ( Mercury and Gemini ), because those astronauts could not move freely in
14960-464: The small cabins of those spacecraft. The increased cabin space in the Apollo command module afforded astronauts greater freedom of movement, contributing to symptoms of space sickness for Borman and, later, astronaut Rusty Schweickart during Apollo 9. The cruise phase was a relatively uneventful part of the flight, except for the crew's checking that the spacecraft was in working order and that they were on course. During this time, NASA scheduled
15096-400: The space station, cislunar, and lunar landing missions. Once Kennedy's Moon landing goal became official, detailed design began of a command and service module (CSM) in which the crew would spend the entire direct-ascent mission and lift off from the lunar surface for the return trip, after being soft-landed by a larger landing propulsion module. The final choice of lunar orbit rendezvous changed
15232-429: The spacecraft into Passive Thermal Control (PTC), also called "barbecue roll", in which the spacecraft rotated about once per hour around its long axis to ensure even heat distribution across the surface of the spacecraft. In direct sunlight, parts of the spacecraft's outer surface could be heated to over 200 °C (392 °F), while the parts in shadow would be −100 °C (−148 °F). These temperatures could cause
15368-399: The spacecraft to take photographs of the spent stage and then practiced flying in formation with it. As the crew rotated the spacecraft, they had their first views of the Earth as they moved away from it—this marked the first time humans had viewed the whole Earth at once. Borman became worried that the S-IVB was staying too close to the CSM and suggested to Mission Control that the crew perform
15504-452: The specification for another competition for spacecraft procurement bids in October 1961. On November 28, 1961, it was announced that North American Aviation had won the contract, although its bid was not rated as good as the Martin proposal. Webb, Dryden and Robert Seamans chose it in preference due to North American's longer association with NASA and its predecessor . Landing humans on
15640-654: The support crew consisted of Ken Mattingly , Vance Brand , and Gerald Carr . The capsule communicator (CAPCOM) was an astronaut at the Mission Control Center in Houston, Texas , who was the only person who communicated directly with the flight crew. For Apollo 8, the CAPCOMs were Michael Collins, Gerald Carr, Ken Mattingly, Neil Armstrong, Buzz Aldrin, Vance Brand, and Fred Haise. The mission control teams rotated in three shifts, each led by
15776-438: The team I was on, and I think it was a very nerve-racking period in general because of this thing with losing signal. You’ve got this big mystery going on there on the backside of the Moon. You do not know what’s happening and there’s not a darn thing anybody here can do about it until we hear from them" With ten minutes remaining before LOI-1, the crew began one last check of the spacecraft systems and made sure that every switch
15912-427: The technical details of the space program, and was put off by the massive financial commitment required by a crewed Moon landing. When Kennedy's newly appointed NASA Administrator James E. Webb requested a 30 percent budget increase for his agency, Kennedy supported an acceleration of NASA's large booster program but deferred a decision on the broader issue. On April 12, 1961, Soviet cosmonaut Yuri Gagarin became
16048-408: The testing of which he had closely supervised, for CM-104, although the two were almost identical, and Anders was less than enthusiastic about being an LMP on a flight with no LM. Instead, Apollo 8 would carry the LM test article, a boilerplate model that would simulate the correct weight and balance of LM-3. Added pressure on the Apollo program to make its 1969 landing goal was provided by
16184-452: The third crewed Apollo flight was officially announced at the same time as the prime crew. When Lovell was reassigned to the prime crew, Aldrin was moved to CMP, and Fred Haise was brought in as backup LMP. Armstrong would later command Apollo 11, with Aldrin as LMP and Collins as CMP. Haise served on the backup crew of Apollo 11 as LMP and flew on Apollo 13 as LMP. During Projects Mercury and Gemini, each mission had
16320-426: The third crewed Apollo flight was officially announced on November 20, 1967. Collins was replaced by Jim Lovell in July 1968, after suffering a cervical disc herniation that required surgery to repair. This crew was unique among pre- Space Shuttle era missions in that the commander was not the most experienced member of the crew: Lovell had flown twice before, on Gemini VII and Gemini XII . This would also be
16456-889: The three-person Apollo command and service module directly to the lunar surface, on top of a large descent rocket stage, would require a Nova-class launcher, with a lunar payload capability of over 180,000 pounds (82,000 kg). The June 11, 1962, decision to use lunar orbit rendezvous enabled the Saturn V to replace the Nova, and the MSFC proceeded to develop the Saturn rocket family for Apollo. Since Apollo, like Mercury, used more than one launch vehicle for space missions, NASA used spacecraft-launch vehicle combination series numbers: AS-10x for Saturn I, AS-20x for Saturn IB, and AS-50x for Saturn V (compare Mercury-Redstone 3 , Mercury-Atlas 6 ) to designate and plan all missions, rather than numbering them sequentially as in Project Gemini. This
16592-406: The understanding of the Moon's composition and geological history. The program laid the foundation for NASA's subsequent human spaceflight capability and funded construction of its Johnson Space Center and Kennedy Space Center . Apollo also spurred advances in many areas of technology incidental to rocketry and human spaceflight, including avionics , telecommunications, and computers. The program
16728-474: The way for Apollo 10 and, with Apollo 11 in July 1969, the fulfillment of U.S. president John F. Kennedy 's goal of landing a man on the Moon before the end of the decade. The Apollo 8 astronauts returned to Earth on December 27, 1968, when their spacecraft splashed down in the northern Pacific Ocean. The crew members were named Time magazine 's "Men of the Year" for 1968 upon their return. In
16864-430: The workability of the approach. In late 1961 and early 1962, members of the Manned Spacecraft Center began to come around to support LOR, including the newly hired deputy director of the Office of Manned Space Flight, Joseph Shea , who became a champion of LOR. The engineers at Marshall Space Flight Center (MSFC), who were heavily invested in direct ascent, took longer to become convinced of its merits, but their conversion
17000-482: Was 11.42 feet (3.48 m) tall, 12.83 feet (3.91 m) in diameter, and weighed approximately 12,250 pounds (5,560 kg). A cylindrical service module (SM) supported the command module, with a service propulsion engine and an RCS with propellants, and a fuel cell power generation system with liquid hydrogen and liquid oxygen reactants. A high-gain S-band antenna was used for long-distance communications on
17136-470: Was a second mid-course correction. It was in retrograde (against the direction of travel) and slowed the spacecraft down by 2.0 ft/s (0.61 m/s), effectively reducing the closest distance at which the spacecraft would pass the Moon. At exactly 61 hours after launch, about 24,200 miles (38,900 km) from the Moon, the crew burned the RCS for 11 seconds. They would now pass 71.7 miles (115.4 km) from
17272-567: Was an upgraded version of the Saturn I. The S-IB first stage increased the thrust to 1,600,000 pounds-force (7,120 kN) by uprating the H-1 engine. The second stage replaced the S-IV with the S-IVB-200 , powered by a single J-2 engine burning liquid hydrogen fuel with LOX, to produce 200,000 pounds-force (890 kN ) of thrust. A restartable version of the S-IVB was used as the third stage of
17408-497: Was announced by Wernher von Braun at a briefing on June 7, 1962. But even after NASA reached internal agreement, it was far from smooth sailing. Kennedy's science advisor Jerome Wiesner , who had expressed his opposition to human spaceflight to Kennedy before the President took office, and had opposed the decision to land people on the Moon, hired Golovin, who had left NASA, to chair his own "Space Vehicle Panel", ostensibly to monitor, but actually to second-guess NASA's decisions on
17544-606: Was changed by the time human flights began. Since Apollo, like Mercury, would require a launch escape system (LES) in case of a launch failure, a relatively small rocket was required for qualification flight testing of this system. A rocket bigger than the Little Joe used by Mercury would be required, so the Little Joe II was built by General Dynamics / Convair . After an August 1963 qualification test flight , four LES test flights ( A-001 through 004 ) were made at
17680-437: Was chosen in Houston , Texas, on land donated by Rice University , and Administrator Webb announced the conversion on September 19, 1961. It was also clear NASA would soon outgrow its practice of controlling missions from its Cape Canaveral Air Force Station launch facilities in Florida, so a new Mission Control Center would be included in the MSC. In September 1962, by which time two Project Mercury astronauts had orbited
17816-617: Was erected in the Vehicle Assembly Building on December 20, 1967, it was thought that the rocket would be used for an uncrewed Earth-orbit test flight carrying a boilerplate command and service module. Apollo 6 had suffered several major problems during its April 1968 flight, including severe pogo oscillation during its first stage, two second-stage engine failures, and a third stage that failed to reignite in orbit. Without assurances that these problems had been rectified, NASA administrators could not justify risking
17952-529: Was named after Apollo , the Greek god of light, music, and the Sun, by NASA manager Abe Silverstein , who later said, "I was naming the spacecraft like I'd name my baby." Silverstein chose the name at home one evening, early in 1960, because he felt "Apollo riding his chariot across the Sun was appropriate to the grand scale of the proposed program". The context of this was that the program focused at its beginning mainly on developing an advanced crewed spacecraft,
18088-513: Was placed on top of the rocket on September 21, and the rocket made the slow 3-mile (4.8 km) journey to the launch pad atop one of NASA's two massive crawler-transporters on October 9. Testing continued all through December until the day before launch, including various levels of readiness testing from December 5 through 11. Final testing of modifications to address the problems of pogo oscillation, ruptured fuel lines, and bad igniter lines took place on December 18, three days before
18224-403: Was the only component of the Apollo spacecraft to survive without major configuration changes as the program evolved from the early Apollo study designs. Its exterior was covered with an ablative heat shield , and had its own reaction control system (RCS) engines to control its attitude and steer its atmospheric entry path. Parachutes were carried to slow its descent to splashdown. The module
18360-414: Was then circularized at 60.7 by 59.7 nautical miles (112.4 by 110.6 km), with an orbital period of 128.7 minutes. The effect of lunar mass concentrations ("mascons") on the orbit was found to be greater than initially predicted; over the course of the ten lunar orbits lasting twenty hours, the orbital distance was perturbated to 63.6 by 58.6 nautical miles (117.8 by 108.5 km). Apollo 8 achieved
18496-466: Was upgraded to 7,610,000 pounds-force (33,900 kN). The second and third stages burned liquid hydrogen; the third stage was a modified version of the S-IVB, with thrust increased to 230,000 pounds-force (1,020 kN) and capability to restart the engine for translunar injection after reaching a parking orbit . Apollo 8 Apollo 8 (December 21–27, 1968) was the first crewed spacecraft to leave Earth's gravitational sphere of influence , and
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