Tricky hatch blamed for three Apollo 1 astronaut deaths

The astronauts practise exiting the capsule. Unfortunately, during the fire, the hatch was too tricky to open in time. Credit: NASA

A fatal design flaw in Apollo 1 led to the deaths 50 years ago of three pioneering astronauts: veteran Gus Grissom, the first American spacewalker Ed White, and rookie Roger Chaffee.

They never made it off the launch pad when fire started in the capsule during a pre-launch test.

The crew couldn't open the capsule's three-part hatch and emergency rescue teams were too late to save them from smoke inhalation.

The problem hatch is now on display for visitors to at Kennedy Space Centre as part of a memorial and to serve as a reminder of the risks of spaceflight.

Former Gemini and Apollo astronaut Tom Stafford spoke at the memorial ceremony, saying that if the accident had occurred in space, they would never have known exactly what happened.

The deaths of these "three great heroes ... helped save at least one other in flight, maybe two," he added.

Investigators discovered several problems with the Apollo capsule design that led to the fire, including an electrical wiring issue, a pure-oxygen environment and flammable materials throughout the crew cabin.

The subsequent investigation led to major design and engineering changes, making the later Apollo trips safer, eventually resulting in the moon landing in 1969.

NASA has uploaded a video and online memorial to commemorate the 50th anniversary of the event.

The new hatch devised after the accident, which could be opened from the inside with a couple of simple actions. Credit: NASA