Mariner 1NASA launches the JPL-built unmanned space probe Mariner 1, the first of two identical spacecraft intended to study the planet Venus. Mariner 1’s mission, however, is cut short before it even leaves Earth’s atmosphere: a communication loss between its Atlas-Agena booster rocket and ground-based control systems sends the rocket off course. Fearing that it might tumble into the Atlantic Ocean’s heavily traveled shipping lanes, NASA orders the vehicle to self-destruct in mid-air. Many later accounts lay the blame at an error in the code loaded into the rocket’s on-board guidance computer. Mariner 1’s mission objectives are transferred to its identical twin, Mariner 2, due to be launched in just over a month.