The launch date for NASA’s first crewed Apollo mission was set: February 21, 1967. The purpose of the flight was to test launch operations, ground tracking and control facilities, and the performance of the Saturn IB rocket and the Command-Service Module spacecraft.
However, early on in their training the crew - Gus Grissom, Ed White, and Roger Chaffee - voiced concerns with the spacecraft, primarily with the amount of flammable material in the cabin. The astronauts weren’t alone with their concerns. In fact, some experts believed the immense pressure of President John F. Kennedy’s deadline forced NASA and the contractor, North American Aviation, to make decisions that sacrificed safety. One of the main concerns was NASA’s decision to opt for a single gas environment inside the capsule over a dual gas environment because it required a lighter system. This meant that the Apollo spacecraft would use one-hundred percent oxygen in the crew cabin, so even a small spark could quickly turn into a blaze. Adding to that fear, other astronauts reported seeing what appeared to be frayed wires and short circuits in the cabin of the spacecraft. There were also issues with the decision to have the hatch open inward and the fact that it did not carry explosive bolts in case of an emergency.
One month before launch, the rocket and spacecraft were cleared for a “plugs out test”. At 1pm on January 27th, the Apollo 1 astronauts entered the command module, sealed the hatch and prepared for what was considered a dress rehearsal for the actual flight. At 6:31pm the test conductors were ready to start the countdown, but seconds later a flash fire ripped through the spacecraft. It only took about thirty seconds for flames and toxic smoke to engulf the crew cabin, killing the three astronauts.
The investigation that followed the Apollo 1 fire forced a hold on the space program. Going forward, the hard lessons learned from this mission would dictate new stringent checks and balances that would inform all NASA missions to follow, ultimately changing the nation’s path to the moon.