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Apollo 4, the first flight of a Saturn V launch vehicle, rises from Launch Pad 39A
|Mission type||Test flight|
|Mission duration||8 hours, 36 minutes, 59 seconds|
|Manufacturer||North American Rockwell|
|Launch mass||36,856 kilograms (81,253 lb)|
|Start of mission|
|Launch date||November 9, 1967, 12:00:01UTC|
|Rocket||Saturn V SA-501|
|Launch site||Kennedy LC-39A|
|End of mission|
|Landing date||November 9, 1967, 20:37:00UTC|
|Landing site||North Pacific Ocean
|Perigee||183.0 kilometers (98.8 nautical miles)|
|Apogee||Initial: 188.0 kilometers (101.5 nautical miles)
Maximum: 18,092 kilometers (9,769 nautical miles)
Apollo 4, (also known as Apollo-Saturn 501 and AS-501), was the first test flight for the Saturn V, the launch vehicle which was ultimately used by the U.S. Apollo program to send the first astronauts to the Moon. Apollo 4 flew without a crew, and was an "all-up test," meaning all rocket stages and spacecraft would be fully functional on the initial flight, a first for NASA. It was the first time the S-IC first stage and S-II second stage flew. It also demonstrated the S-IVB third stage's first in-flight restart. The mission used a Block I Command Service Module (CSM) modified to test several key Block II revisions, including its heat shield at simulated lunar-return velocity and angle.
The launch, on November 9, 1967, was the first from the John F. Kennedy Space Center on Merritt Island, Florida. The mission lasted almost nine hours, splashing down in the Pacific Ocean, achieving all mission goals. NASA deemed the mission a complete success, because it proved the Saturn V worked, an important step towards achieving the Apollo program's primary objective: landing astronauts on the Moon, and bringing them back safely before the end of the decade.
AS-501 was the Saturn V's first flight. At the time, it was the largest launch vehicle to ever attempt a flight. This mission was NASA's first to use "all-up" testing, a decision that goes back to late-1963. George Mueller, the head of the NASA Office of Manned Space Flight at that time, was a systems engineer who previously worked on military missile projects, recognized all-up testing was successfully used to rapidly develop the Air Force's Minuteman ICBM program, and thought it could be used to meet Apollo's schedule. Previously, the way Wernher von Braun's team at the Marshall Space Flight Center, and the old N.A.C.A. Langley Research Center engineers tested new rockets was by testing each stage incrementally. The Saturn V's test program departed from the conservative incremental approach previously used by the Marshall and Langley engineers. It would be tested all at once, with all stages live and fully flight-worthy, including an Apollo Command/Service Module (CSM). This decision dramatically streamlined the program's test flight phase, eliminating four missions, but it required everything to work properly the first time. Apollo program managers had misgivings about all-up testing but agreed to it with some reluctance since incremental component tests would inevitably push the lunar landing mission past the 1970 goal.
The mission was the first launch from the Kennedy Space Center Launch Complex 39, specifically built for the Saturn V. Since this was an all-up test, it was the S-IC first stage and S-II second stage's first launch. 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.
The payload was a 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 fly without a crew. The modifications included: a new CM heat shield outer covering; a new CM-to-SM umbilical connector; moving the VHF scimitar antennas from the CM to the SM; a new Unified S-band antenna; and a modified crew compartment hatch.
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.
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.
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.
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 Vertical Assembly Building (VAB) - almost six months after the originally scheduled launch date.
The vehicle's on-pad, pre-launch tests started in September, and encountered several problems with propellant loading and various equipment failures, pushing the launch into November, but providing valuable lessons learned on the new vehicle's launch operations. By this time, North American had been purchaced by Rockwell Standard Corporation, so launch support was the first provided under the new name, North American Rockwell. On November 6, the 56½ hour countdown sequence began with propellant loading. 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). This time the problems encountered were few and minor.
Launch occurred on November 9 at 7:00AM EST (12:00PM UTC). 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 (see below), the launch pads at LC-39 were located more than three miles from the Vertical 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. Cronkite and producer Jeff Grlnick put their hands on the observation window in an effort to stop its powerful vibrations. Cronkite later admitted he was "overwhelmed" by the power of the rocket and the emotion of the moment that reduced his descriptions to "look at that rocket go into the clouds at 3000 feet!...you can see it...you can see it...oh the roar is terrific!...". NASA later built a sound suppression system that pumped thousands of gallons of water onto the flame trench under the pad.
Much like with the Saturn I's maiden flight six years earlier, the fear of a low altitude launch failure and especially a pad explosion was high. Several NASA studies had been conducted to assess this scenario by studying previous such accidents (notably the March 1965 Atlas-Centaur disaster), but in all such cases, they involved launch vehicles less than half the size and fuel load of the Saturn V. Such an event would be a catastrophe beyond all proportions (the Soviet N-1 disaster of 1969 however provides a glimpse of what it might have looked like). Fortunately for all concerned, the largest rocket ever built lifted from LC-39A and performed perfectly through all stages of the flight.
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.
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.
Saturn V cameras
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 four-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 (61 km) 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.
The Command Module contained an automatic 70 mm film camera which captured 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.
- Saturn V Launch Vehicle Flight Evaluation Report - AS-501 Apollo 4 Mission (PDF). George C. Marshall Space Flight Center: NASA. January 15, 1968. MPR-SAT-FE-68-1. Retrieved July 8, 2013.
- Reynolds 2002, pp. 81–82
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- Brooks 1979, "Apollo 4 and Saturn V", CH9-5
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- "Cronkite", Douglas Brinkley, Harper Collins 2012
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- Woods, Apollo 4 Saturn V first stage and interstage separation film (FTV-0002003)
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- Woods, W. David; MacTaggart, Kenneth D.; O'Brien, Frank. "Apollo 11, Day 1, part 1: Launch". Apollo Flight Journal. Washington, D.C.: NASA. Retrieved July 8, 2013.
|Wikimedia Commons has media related to Apollo 4.|
- "Apollo 4" at NASA's National Space Science Data Center
- John C. Stennis Space Center
- Apollo 4 Mission - 1967 NASA Educational Documentary on YouTube
- DEBUGGING A LIVE SATURN V