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) and 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.

The Pegasus satellite program was a series of three American satellites launched in 1965 to study the frequency of micrometeorite impacts on spacecraft. All three Pegasus satellites were launched by Saturn I rockets, and remained connected with their upper stages.