On January 27, 1967, three Apollo astronauts were killed during a pre-flight exercise at NASA’s Kennedy Space Center. fire Apollo-1 It was the first major fatal disaster in the history of the US space program.
Apollo-1 is the name of the space mission that was supposed to be called the first manned space flight of the Apollo program. But as a result of a fire accident that occurred about a month before the flight during pre-launch training and preparation operations in the Apollo spacecraft, all three astronauts selected for this mission burned alive and died.
The astronauts had to check the electrical circuits used inside the cabin during a simulated launch operation. In this operation, the engineers wanted to achieve the ability to generate electricity inside the cabin.
This test was actually the last important test for the Apollo spacecraft, and if successful, the astronauts had to prepare for a space flight on February 21, 1967.
Description of the Apollo-1 incident
Three astronauts Apollo-1 ie Gus Grissom, Edward White And Roger Chaffee While wearing their astronaut suits, they entered the command unit of the Apollo-1 ship. A bad and strong smell like the smell of rotten milk or the smell of buttermilk filled the entire cabin. Grisham, as commander of the operation, requests that the mission be delayed until the smell clears. After about two hours, Grisham informs the command center that they can no longer smell a scent.
Three minutes later, the hatch of the astronaut’s cabin is completely closed and the air inside is replaced by pure oxygen. Radio communication between the command center and the Apollo astronauts is cut off, according to the simulation program.
In the final minutes, the operations team achieves many of its objectives, and with only ten minutes remaining, communication between the command unit and the ground control center is re-established. In the last information recorded on the spacecraft’s data recorder at 18:30:54, the astronauts report a fire in the cabin to the control center.
It took about ten minutes until the rescue team reached the launch pad, and attempts to open the hatch by the passengers failed due to their capping. Edward White was trying to open the ship’s hatch to escape the flames. But this hatch could not be opened easily and because it was supposed to keep the astronauts safe from the vacuum of space, its creators had made sure that it would not be opened easily.
The rescue team finally made it to the spacecraft, but there were no tools to open the hatch from the outside. The speed of the fire was higher than their speed and finally the rescue team members faced a terrible scene after opening the hatch.
No one expected this incident, that too in a test operation. After this incident, the bodies of the astronauts were buried in an official ceremony with special ceremonies.
The cause of the accident and corrections
The researchers investigated the causes of the Apollo-1 accident and the result was ignition, materials inside the spacecraft and its pure oxygen. For future missions, designers decided to make some changes to the Apollo spacecraft systems, including:
- Changing the composition of the internal atmospheric gases of the astronauts’ cabin with a combination of 40% nitrogen and 60% oxygen with a pressure of one atmosphere
- The gradual reduction of internal pressure when increasing the altitude from the ground to about 0.034 atmospheres and the slow replacement of oxygen up to 100% in the first 24 hours of the spacecraft entering the path to the moon with a pressure of 0.013 atmospheres
- The possibility of opening the entry and exit hatch for astronauts from the outside and installing several explosive bolts that can open the hatch automatically in less than 10 seconds in emergency situations.
- Proper insulation of pipes and wires used in spacecraft with safe materials
- Fixing more than 1400 problems in the internal wiring of the command unit
- Adding a fireproof layer to the astronaut suit