AS-104

AS-104

Launch of Saturn AS-104
Mission type	Spacecraft aerodynamics; micrometeoroid investigation
Operator	NASA
COSPAR ID	1965-039B
SATCAT no.	1385
Mission duration	8,810 days[1]
Distance travelled	3,282,050,195 kilometers (2.039371443×109 mi)
Orbits completed	~79,790
Spacecraft properties
Spacecraft	Apollo BP-26 Pegasus 2
Launch mass	1,451.5 kilograms (3,200 lb)
Start of mission
Launch date	May 25, 1965, 07:35:01 (1965-05-25UTC07:35:01Z) UTC
Rocket	Saturn I SA-8
Launch site	Cape Kennedy LC-37B
End of mission
Decay date	July 8, 1989 (1989-07-09)[1]
Orbital parameters
Reference system	Geocentric
Regime	Low Earth orbit
Perigee altitude	511 kilometers (318 mi)
Apogee altitude	739 kilometers (459 mi)
Inclination	31.7 degrees
Period	97.2 minutes
Epoch	4 July 1965[2]
Apollo program ← AS-103 AS-105 →

AS-104 was the fourth orbital test of a boilerplate Apollo spacecraft, and the second flight of the Pegasus micrometeoroid detection satellite. It was launched by SA-8, the ninth Saturn I carrier rocket.

Objectives

The primary mission objective was to demonstrate the launch vehicle's iterative guidance mode and to evaluate system accuracy. The launch trajectory was similar to that of mission AS-103.

The Saturn launch vehicle SA-8 and payload were similar to those of mission AS-103, except that a single reaction control engine assembly was mounted on the boilerplate service module (BP-26). The assembly was instrumented to acquire additional data on launch environment temperatures. This assembly also differed from the one on the AS-101 mission in that two of the four engines were of a prototype configuration instead of all engines being simulated.

Launch

This was the first nighttime launch in the Saturn I series. A built-in 35 minute hold was used to ensure that launch time coincided with the opening of the launch window.

AS-104 was launched from Cape Kennedy Launch Complex 37B at 2:35:01 a.m. EST (07:35:01 GMT) on May 25, 1965.^[3] The launch was normal and the payload was inserted into orbit approximately 10.6 minutes after lift-off. The total mass placed in orbit, including the spacecraft, Pegasus B, adapter, instrument unit, and S-IV stage, was 34,113 pounds (15,473 kg). The perigee and apogee were 314.0 and 464.1 miles (505 and 747 km), respectively; the orbital inclination was 31.78'. The 1397 kilogram (3080-pound) Pegasus 2 satellite was also carried to orbit by SA-8, being stowed inside the boilerplate's service module, and remaining attached to the S-IV stage.

The actual trajectory was close to the one predicted, and the spacecraft was separated 806 seconds after lift-off. Several minor malfunctions occurred in the S-I stage propulsion system; however, all mission objectives were achieved.^[4][5]

Launch complexesGround facilitiesLaunch vehiclesSpacecraft and roverFlights

Uncrewed	AS-101 AS-102 AS-201 AS-202 Apollo 4 Apollo 5 Apollo 6†
Crewed	Apollo 1† Apollo 7 Apollo 8 Apollo 9 Apollo 10 Apollo 11 Apollo 12 Apollo 13† Apollo 14 Apollo 15 Apollo 16 Apollo 17
Saturn development	Saturn-Apollo 1 SA-2 SA-3 SA-4 SA-5 AS-203 Apollo 4 Apollo 6†
Abort tests	QTV Pad Abort Test-1 A-001 A-002 A-003 Pad Abort Test-2 A-004
Pegasus flights	AS-103 AS-104 AS-105

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