Apollo 13 set off into space 50 years ago today. An ignored change order ensured it did not make it to the Moon...

A liquid-oxygen tank, 65 volts across a 28-volt thermostat, and a two-inch tumble all led to this 'successful failure'

Part one Apollo 13 was launched 50 years ago today. Now regarded as a "successful failure," the story of the aborted Moon landing began years earlier, with the design of mankind's then most advanced spacecraft."