THE SPACECRAFT The first U.S. spaceship was a cone-shaped one-man capsule with a cylinder mounted on top. Two meters (6 ft, 10 in) long, 1.9 meters (6 ft, 2 1/2 in) in diameter, a 5.8 meter (19 ft, 2 in) escape tower was fastened to the cylinder of the capsule. The blunt end was covered with an ablative heat shield to protect it against the 3000 degree heat of entry into the atmosphere. The Mercury program used two launch vehicles: A Redstone for the suborbital and an Atlas for the four orbital flights. Prior to the manned flights, unmanned tests of the booster and the capsule, carrying a chimpanzee, were made. Each astronaut named his capsule and added the numeral 7 to denote the teamwork of the original astronauts.