| Apollo 4 | |||||
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| Mission insignia |
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| Mission statistics[1] | |||||
| Mission name | Apollo 4 | ||||
| Command Module | CM-017 | ||||
| Service Module | SM-017 CM+SM 51,753 lb (23,475 kg) mass |
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| Lunar Module | LTA-10R (dummy) 29,500 lb (13,400 kg) mass |
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| Spacecraft mass | 81,253 pounds (36,856 kg) | ||||
| Crew size | Unmanned | ||||
| Launch vehicle | Saturn V SA-501 | ||||
| Launch pad | Complex 39A Kennedy Space Center Florida, USA |
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| Launch date | November 9, 1967 12:00:01 UTC |
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| Landing | November 9, 1967 20:37:00 UTC North Pacific Ocean |
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| Mission duration | 8 h 36 m 59 s | ||||
| Number of orbits | 3 | ||||
| Apogee | 101.5 nmi (188.0 km) (initial) 9,769 nmi (18,092 km) (maximum) |
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| Perigee | 98.8 nmi (183.0 km) (initial) −40 nmi (−74.1 km) (final orbit) |
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| Orbital period | 88.3 m | ||||
| Orbital inclination | 32.6° | ||||
| Distance traveled | ~85,000 mi (~140,000 km) | ||||
| Related missions | |||||
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Apollo 4, (also known as Apollo-Saturn 501 and AS-501), was the first unmanned test flight of the Saturn V launch vehicle, which was ultimately used by the Apollo program to send the first men to the Moon. Apollo 4 flew the S-IC first stage and S-II second stage for the first time, and demonstrated the first in-flight restart of the S-IVB third stage, and the first test of the Apollo heat shield in flight at expected lunar return velocity and angle.
The launch, at 7:00 a.m. EST on November 9, 1967 from Launch Complex 39, was the first from the John F. Kennedy Space Center on Merritt Island, Florida. It lasted only 8 hours and 37 minutes, just long enough to test orbital rocket restart and send the command module to a sufficient altitude, and allow it to fire the service module engine to build up the correct return velocity to fully simulate return of a moon mission. The mission tested the complete Saturn V and Apollo Command/Service Module (CSM) stack in what is known in the aerospace industry as an "all-up test", meaning all stages were live and functional on the first flight. The mission used a Block I CSM modified to test several important Block II revisions, including its heat shield at simulated lunar-return speeds of approximately 36,500 feet per second (11,100 m/s).
The mission was deemed a complete success by NASA, and significantly advanced Apollo toward its goal of landing men on the Moon by the end of the 1960s.
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This was the first flight of the Saturn V, the largest launch vehicle ever to fly successfully. It was also the first launch from Launch Complex 39, which was specifically built for the Saturn V. As well as being the first launch of the S-IC first stage and S-II second stage, it would also be the first time that the S-IVB third stage would be restarted in Earth orbit, and the first time that the Apollo spacecraft would reenter the Earth's atmosphere at the speed of a lunar return trajectory. Because of all these firsts, there were 4,098 measuring instruments on board the rocket and spacecraft.
This would be the first use of the all-up testing method. It had been decided in 1963 that instead of testing each stage of the rocket separately as had been done on all previous US multistage rocket programs, the Saturn V would be tested all at once. This cut down the total number of tests, as needed to accomplish President Kennedy's stated goal of a manned lunar landing by 1970, but it meant that everything had to work properly the first time. Apollo program managers had misgivings about all-up testing but agreed to it with some reluctance since individual component tests would inevitably push the landing mission past the 1970 goal.[2][3]
The payload was the Apollo Command/Service Module (CSM), serial number 017. This was a Block I design meant for systems testing, not the Block II spacecraft designed for use with the Lunar Module (LM) on the actual Moon landings. However, several significant Block II modifications were made for certification, since no all-up Block II spacecraft would be flown before the first manned missions. These included: a new CM heat shield outer covering; a new CM-to-SM umbillical connector; moving the VHF scimitar antennas from the CM to the SM; a new Unified S-Band antenna; and a modified crew compartment hatch.[1]
A dummy LM known as a Lunar Module Test Article, LTA-10R was carried as ballast to simulate the loadings of the LM on the launch vehicle. At 29,500 pounds (13,400 kg), the LTA-10R was slightly lighter than a nominal LM used on the first lunar landing, which weighed 33,278 pounds (15,095 kg).
The launch of AS-501 was originally planned for late 1966, but was pushed back by stage development problems to April, 1967. The first piece to arrive at the Kennedy Space Center was the S-IVB third stage, on August 14, 1966. Built by Douglas Aircraft Company, it was small enough to be transported by a specially built plane, the "Pregnant Guppy" built by Aero Spacelines, Inc.[4]
The other stages were much larger and had to travel by barge, with the first stage arriving next on September 12 from the Boeing Company at Michoud, Louisiana along the Banana River. The second stage, built by North American Aviation, was experiencing the greatest development delays, and did not make delivery in 1966. In the meantime, vehicle assembly continued using a huge spool-shaped spacer in the place of the second stage.[4]
The CSM, also built by North American Aviation, arrived on December 24, 1966, followed by the tardy S-II second stage on January 21, 1967. Six days later, the fatal Apollo 1 spacecraft fire occurred, placing all schedules in question.[4]
Then, problems requiring rework were discovered in the North American components. An inspection of wiring in the CSM found 1,407 problems, and it was removed from the stack on February 14 for repair. Worse still, cracks were found in the S-II liquid hydrogen tank. These were repaired and the S-II was finally stacked on February 23. The CSM repairs required another four months until it was ready to be re-mated to the rocket on June 20. On August 26, the complete launch vehicle, now designated Apollo 4, finally rolled out of the VAB - almost six months after the originally scheduled launch date.[4]
After a testing regime on the pad that lasted two months, the rocket was ready for launch. The propellant started being loaded on November 6. In total there were 89 trailer-truck loads of LOX (liquid oxygen), 28 trailer loads of LH2 (liquid hydrogen), and 27 rail cars of RP-1 (refined kerosene).
Launch occurred at 12:00 UTC on November 9. Eight seconds before liftoff, the five F-1 engines ignited, sending tremendous amounts of noise across Kennedy Space Center. To protect from a possible explosion, the launch pads at LC-39 were located more than three miles from the Vehicle Assembly Building; still, the sound pressure was much stronger than expected and buffeted the VAB, Launch Control Center and press buildings. Ceiling tiles fell around news reporter Walter Cronkite, covering the launch for CBS News booth. NASA later built a sound suppression system that pumped thousands of gallons of water onto the flame trench under the pad.
The launch placed the S-IVB and CSM into a nearly circular 100-nautical-mile (190 km) orbit, a nominal parking orbit that would be used on the actual lunar missions. After two orbits, the S-IVB reignited for the first time, putting the spacecraft into an elliptical orbit with an apogee of 9,297 nautical miles (17,218 km) and a perigee that would deliberately take it 45.7 nautical miles (84.6 km) below the Earth's surface; this would ensure both a high-speed reentry of the Command Module, and atmospheric reentry and destruction of the S-IVB. The CSM then separated from the S-IVB and fired its Service Module engine to raise the apogee to 9,769 nautical miles (18,092 km) and a perigee of −40 nautical miles (−74 km). After passing apogee, the Service Module engine fired again for 281 seconds to increase re-entry speed to 36,545 feet per second (11,139 m/s), at an altitude of 400,000 feet (120 km) and a flight path angle of -6.93 degrees, simulating a return from the Moon.[5].[1]
The CM landed approximately 8.6 nautical miles (16 km) from the target landing site northwest of Midway Island in the North Pacific Ocean. Its descent was visible from the deck of the USS Bennington, the prime recovery ship.
Documentaries often use footage of a Saturn V launch, and one of the most used pieces shows the interstage between the first and second stages falling away. This footage is usually mistakenly attributed to the Apollo 11 mission, when it was actually filmed on the flights of Apollo 4 and Apollo 6.
A compilation of original NASA footage shows the jettisoning of the first stage (S-IC) and the interstage, filmed from the bottom of the second stage (S-II), both from Apollo 4. This is followed by footage of the separation of an S-IVB second stage from the first stage of a Saturn IB. The glow seen on the jettisoned stages is due to the hot, invisible hydrogen-oxygen flames of the J-2 engines used by the S-II and S-IVB. The footage also shows the more conspicuous plumes of the solid ullage motors as they pull the stages apart before the main engines are fired.
The cameras ran at 15 times normal speed to show the events in slow motion. The camera capsules were jettisoned soon after the first stage separation and though at about 200,000 feet in altitude, were well below orbital velocity. They then reentered the atmosphere and parachuted to the ocean where they floated waiting for recovery. Both S-II cameras from Apollo 4 were recovered so that there is footage from both sides of the vehicle.[1]
The Command Module contained an automatic 70 mm film camera which captured the first photographs of almost the entire Earth. For a period of two hours and thirteen minutes as the craft approached and passed its apogee, a total of 755 color images were taken through the Command Pilot's (left-hand) forward-looking window, at altitudes ranging from 7,295 to 9,769 nautical miles (13,510 to 18,092 km). The photographs were not of sufficient resolution to obtain detailed scientific data, but were still of geographic, cartographic, meteorologic, oceanographic, geologic and hydrologic interest.[5]
An image of the crescent Earth from Apollo 4 appeared on the front cover of The Last Whole Earth Catalog, with the following credit:
| “ | This is probably the first American photograph of the "whole Earth." You're looking west over the Atlantic Ocean, with the Antarctic continent just visible at the bottom of the crescent. The picture was released in 1967, but no one seemed to care about noticing it or publishing it. I think it was the shadow, which frightened people. There are no shadows on our maps.[6] | ” |
The Command Module is on display at the NASA's John C. Stennis Space Center, Bay St. Louis, Mississippi.
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