SA-4 (Apollo)

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Saturn-Apollo 4
Mission Insignia
Saturn Apollo insignia
Mission Statistics
Mission Name: Saturn-Apollo 4
Call Sign: SA-4
Launch: March 28, 1963
20:11:55 UTC
Cape Canaveral
Complex 34
Landing: March 28, 1963
20:26:55 UTC
Duration: 15 min 0 s
Number of
Orbits:		 Suborbital
Apogee: 80.2 mi (129 km)
Distance
Traveled:		 248.5 mi (400 km)
Apogee Mass: 52,480 kg
SA-4

SA-4 was the fourth launch of a Saturn I launch vehicle and the last of the initial test phase of the first stage. It was part of the Apollo Program.

[edit] Objectives

SA-4 was the last flight to just test the S-I first stage of the Saturn I rocket. As with the first three launches this would be a suborbital flight and would test the structural integrity of the rocket.

The major addition to this flight was that to test the rockets ability to deal with an engine failure during the flight, one of the engine would be programmed to shutdown about 100 seconds after launch. If all went well the rocket would reroute the fuel for this engine to the other engines and have the rocket burn longer to compensate for the loss of acceleration. This was used successfully on the later Apollo 6 and Apollo 13 flights.

Also on this flight, the dummy second stage was outfitted with the aerodynamic design of the real second stage. This included vent ducts, fairings and dummy camera pods. The rocket also flew with antennae designed for the Block II version of the rocket.

SA-4 on the pad 34
Enlarge
SA-4 on the pad 34

[edit] Flight

After the shortest checkout time of any rocket at 54 days, SA-4 went on to experience the longest series of holds of any mission at 120 minutes. The SA-4 launch would be the final single-stage flight.

The rocket operated perfectly through the first 100 seconds of the flight, when the Number 5 engine shut off as planned. The rocket then continued to operate properly, with the propellant system rerouting the fuel to the other engines. The Number 5 engine didn't disintegrate due to heat caused by the lack of cooling propellant as some had predicted. This was an important test proving an important feature of the clustered engine design.

The rocket reached a maximum height of 129 km and a peak velocity of 5906 km per hour. At this stage it also fired retrorockets that would be used on later missions to separate the rocket stages. On SA-4 the stages weren't designed to separate but tested the retrorockets to make sure they would fire.

[edit] External links


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Project Apollo		 Apollo Program Insignia
SA-1 | SA-2 | SA-3 | SA-4 | QTV | Pad Abort Test-1 | SA-5 | A-001 | A-101 | A-102 | A-002 | A-103 | A-003 | A-104 | Pad Abort Test-2 | A-105 | A-004 | AS-201 | AS-203 | AS-202 | Apollo 1 | Apollo 4 | Apollo 5 | Apollo 6 | Apollo 7 | Apollo 8 | Apollo 9 | Apollo 10 | Apollo 11 | Apollo 12 | Apollo 13 | Apollo 14 | Apollo 15 | Apollo 16 | Apollo 17
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