A-104

A-104 was the ninth test flight of the Saturn I. This mission was the second flight in the Saturn I operational series and the fourth vehicle to carry an Apollo boilerplate spacecraft. The vehicle also launched the Pegasus B meteoroid technology satellite.

Objectives

The two primary mission objectives were (1) evaluation of meteoroid data sampling in near-earth orbit and (2) demonstration of the launch vehicle iterative guidance mode and evaluation of system accuracy. The launch trajectory was similar to that of mission A-103.

The Saturn launch vehicle (SA-8) and payload were similar to those of mission A-103 except that a single reaction control engine assembly was mounted on the boilerplate service module (BP-26) and the assembly was instrumented to acquire additional data on launch environment temperatures. This assembly also differed from the one on the A-101 mission in that two of the four engines were of a prototype configuration instead of all engines being simulated. Pegasus B weighed approximately 3080 pounds (1397 kg) and had the same dimensions as Pegasus A.

Launch

A-104 was launched from Cape Kennedy Launch Complex 378 at 02:35:01 a.m. EST (07:35:01 GMT) on May 25. 1965, 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.

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'.

Results

The actual trajectory was close to the one predicted, and the spacecraft was separated 806 seconds after lift-off. The deployment of the Pegasus B Wings began about 1 minute later. The predicted orbital lifetime of Pegasus B was 1220 days. The satellite instrumentation and beacons were commanded off on August 29, 1968. Several minor malfunctions occurred in the S-I stage propulsion system; however, all mission objectives were achieved.