Start of America's second manned spaceflight. The Mercury-Redstone rocket lifts off from Cape Canaveral at the start of Mercury MR4, carrying Virgil 'Gus' Grissom into space. Grissom's mission was launched on 21 July 1961. The sub-orbital flight lasted 15 minutes 37 seconds, reaching an altitude of 190.4km. After splash-down, the new explosive exit hatch accidentally detonated. The capsule flooded and sank. Grissom escaped and was safely recovered from the sea. Grissom went on to fly on Gemini 3 in 1965, but was later killed in a launch pad fire prior to Apollo 3 on 27 January 1967.