Mercury-Big-Joe 1

The Mercury-Big-Joe 1 mission tested the ablative heat shield, re-entry dynamics, attitude control and splashdown of the Mercury capsule. For this purpose, a model of the Mercury capsule (Mercury Boilerplate) was launched with an Atlas D rocket.

On September 9, 1959, at 08:19 GMT, the Atlas 10-D rocket lifted off from Launch Complex 14 (LC-14) at Cape Canaveral. Everything went well but, after two minutes, the telemetry display indicated that the rocket’s two outer engines had not separated from the Atlas rocket as planned. The dead weight of the outer engines meant that the planned altitude could not be reached. In addition, the capsule was separated from the rocket by 138 seconds too late.

The capsule therefore splashed down 800 km too early. However, the heat shield worked as planned and the capsule survived reentry undamaged. Because this flight was able to collect enough data, the planned Big Joe 2 mission was canceled.

The launch of Big-Joe 1 was originally scheduled for July 4, 1959, but was postponed twice due to main engine problems and later telemetry problems.

On this mission, the Mercury capsule flew over a distance of 2,407 km, with a peak at an altitude of 153 km. The payload (Mercury boilerplate) weighed 1.159 kg.