Apollo 4

Apollo 4

COSPAR ID	1967-113A
SATCAT no.	03032
Crew
Members	Unmanned

Apollo 4 was the first unmanned flight of the Saturn V launch vehicle. It was also the first flight of the S-IC and S-II stages of the rocket.

Objectives

Early morning view on November 9, 1967

This was the first flight of the Saturn V, the largest launch vehicle ever constructed. It was also the first launch from Launch Complex 39 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 had been restarted in Earth orbit and the first time that the Apollo spacecraft had reentered the Earth's atmosphere at speeds approaching those 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 test of the all-up doctrine. It had been decided in 1963 that instead of testing each component of the rocket separately like had been done by Wernher von Braun in Germany during World War II, the rocket would be tested all at once. This cut down the total number of tests, as needed to accomplish former president Kennedy's stated goal of a manned lunar landing before 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.

There were two main payloads on board. CSM-017 was a production model of the spacecraft that would take the astronauts to the moon. It was a Block I spacecraft meant for testing the systems, and not the Block II spacecraft that would be actually manned. However it did feature some Block II items such as an improved heatshield and a new hatch. The other payload was LTA-10R which was a model of the Lunar Module carried as ballast but with the same mass distribution as the real thing.

The pieces arrive

Apollo 4 instrument unit

The first piece of the Apollo 4 to arrive at the Kennedy Space Center was the third stage. This was built by Douglas Aircraft Company and was small enough to be transported by plane, though it was no ordinary plane, being an Aero Spacelines, Inc. Pregnant Guppy. The other stages were much larger and had to travel by barge, with the first stage arriving next from Boeing Company at Michoud, Louisiana along the Banana River. The second stage was late in arriving but the rocket was still erected in the Vertical Assembly Building, using a huge barbell shaped spool in the place of the second stage.

The Command and Service Module (CSM) arrived at the Cape on Christmas Eve 1966, followed by the second stage on 12 January 1967. Only two weeks later the fatal fire in the Apollo 1 spacecraft occurred pushing all the schedules back. An inspection of wiring in the CSM found 1,407 problems.

The stacking of the S-II took place on 23 February. This was a precision process; supposedly the crane operators could conceivably "lower the crane hook on top of an egg without breaking the shell". The piece had to be unstacked after hairline cracks were found in another S-II. Inspection found nothing wrong with the Apollo 4 stage. The CSM was finally ready as well and on 20 June it was mated to the rocket and the whole launch vehicle rolled out of the VAB on 26 August - six months after the originally scheduled launch date.

Flight

The Saturn V of Apollo 4 rising from the launch pad.

After a testing regime that lasted two months the rocket was finally ready for launch. The propellant started being loaded on 6 November. 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).

The force of the 7.5 million pounds (34 million newtons) of thrust from the launching rocket sent shockwaves across Kennedy Space Center. In anticipation of this (as well as the possibility that the Saturn V might explode), the launch pads at LC-39 were constructed nearly four miles away from the Vehicle Assembly Building. However, the shockwaves were much stronger than expected, and buffeted the VAB, firing room and press buildings. The ceiling tiles in the CBS newsroom that had been constructed at the Cape for the launch started to fall around Walter Cronkite. After the incident, NASA devised a sound suppression system where thousands of gallons of water pumped from the Atlantic Ocean would flow around the exhaust ports of the engines, deadening any shockwaves to the point that they would no longer pose a threat to the buildings outside the danger zone.

The launch was perfect and placed the S-IVB and CSM into a 185 kilometer orbit. After two orbits of the Earth, the S-IVB reignited for the first time in Earth's orbit to put the spacecraft into an elliptical orbit with an apogee of more than 17,000 kilometers. The CSM then fired its own engine to send it out to 18,000 kilometers. Once it had passed the farthest point from Earth, the Service Module engine fired once again to increase the speed of the spacecraft to 40,000 km/h when it reentered the atmosphere.

It landed 16 km from the target landing site but its descent was visible from the deck of the USS Bennington, the prime recovery vessel.

Cameras

Often during documentaries, footage is needed of a Saturn V launch. One of the most used pieces shows the interstage between the first and second stages falling away. Often this is attributed to the Apollo 11 mission, when in fact it was filmed on the flights of Apollo 4 and Apollo 6. Footage from Apollo 4 is seen in the Star Trek episode "Assignment: Earth."

The cameras filmed at high speeds causing the slow motion look of the sequence when seen in a documentary. The camera capsules were jettisoned soon after the first stage separation and though at about 200,000 feet in altitude, were still 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.

Capsule location

The Command Module is on display at the NASA's John C. Stennis Space Center, Bay St. Louis, Mississippi.

External links

• Apollo 4 flight listing NASA NSSDC catalog
• Moonport: A History of Apollo Launch Facilities and Operations
• Chariots for Apollo: A History of Manned Lunar Spacecraft
• John C. Stennis Space Center