Big Joe

Big Joe was a subprogram of Project Mercury. It comprised a single flight using the Atlas launch vehicle, and a boilerplate Mercury capsule. The purpose of the Big Joe Program was to prove the ablative heatshield which would be used for Mercury orbital missions.

Mission Numbering

The official Mercury mission numbering designation was a two letter designation which corresponded to the launch vehicle type, followed by a dash then a 1 or two character designation of the flight/test number. So the official designation for the only Big Joe flight was BJ-1.

Atlas Launch Vehicle Numbering

The launch vehicle used for BJ-1 ("628/10-D") has a slightly different numbering scheme than those used for the later Mercury-Atlas flights.