Friday, July 17, 2009

Apollo 4

Apollo 4 was the first flight of the Saturn V launch vehicle, carrying no crew. 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 to fly successfully. 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 as 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 President Kennedy's stated goal of a manned lunar landing by 1970, but it meant that everything had to work properly the first time (as the Soviets found to their dismay with their Moon rocket). 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. It was a Block I design meant for systems testing, and not the Block II spacecraft that had the docking mechanisms necessary for landing on the Moon. However it did feature some Block II upgrades such as an improved heat shield 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 craft.

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 five F-1 engines sent a huge amount of noise across Kennedy Space Center. To protect from a possible explosion, the launch pads at LC-39 were nearly four miles from the Vehicle Assembly Building. However, the noise was much stronger than expected and buffeted the Vehicle Assembly Building, firing room and press buildings. Ceiling tiles fell around Walter Cronkite in the CBS news booth. NASA later built a sound suppression system that pumps thousands of gallons of water onto the flame trench under the pad. A similar system is still used today with Space Shuttle launches.

The perfect launch placed the S-IVB and CSM into a 185 kilometer orbit. After two orbits, the S-IVB reignited for the first time, putting the spacecraft into an elliptical orbit with an apogee of more than 17,000 kilometers. The CSM separated from the S-IVB and fired its Service Propulsion System (SPS) engine to send it out to 18,000 kilometers. Passing apogee, the Service Propulsion System fired again to increase re-entry speed to 40,000 km/h, simulating a return from the moon.

The CM landed 16 km from the target landing site. Its descent was visible from the deck of the USS Bennington, the prime recovery vessel.

http://en.wikipedia.org/wiki/Apollo_4

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