40 Years Ago

An oxygen tank exploded in the Service Module of Apollo 13. The successful return of the crew was a triumph of jury-rig engineering and a good deal of luck.

The good luck extended until the last minutes. Normal procedure was to use electrical heaters to warm the capsule's parachutes, as they would be super-chilled by the coldness of space. But there was not enough electrical power available to do that and nobody was sure that the parachutes would not just be shredded when they were deployed.