Little Joe (rocket)

Little Joe was a small solid-fuel booster rocket that NASA flew eight times from Wallops Island, Virginia, between 1959 and 1961 to prove out hardware for Project Mercury. Its job was to test the Mercury launch escape system and the capsule heat shield on a cheap, simple vehicle, because the Atlas and even the Redstone were far too costly to use for the many early test flights. The vehicle clustered four modified Sergeant motors, known as Castor or Pollux depending on the modification, with four smaller Recruit motors that fired in varying sequences, and it carried no electronic guidance. North American Aviation built the airframes under a contract awarded in December 1958. Little Joe was among the first launch vehicles to use the rocket cluster principle, and its name is credited to Maxime Faget, who took it from the four large fins that recalled a roll of four in craps. A larger successor, Little Joe II, later tested the Apollo launch escape system.