Apollo 1 Fire
Engineering Disaster by Matthew Grosmick
Apollo 1 was the first manned mission planned to land on the moon for the United States. At the time, the U.S. was competing with the Soviet Union in the space race. This mission planned to put the first man on the moon, beating anything the Soviet Union had ever done in space. The target date of the launch was February 21, 1967, but, in preparation for this date, major problems and human ignorance took the lives of three astronauts. Less than a month away from launch, on January 27, 1967, a fire swept through the cabin of the command module where they were performing a preflight test. All astronauts in the cabin were killed including Gus Grissom, Ed White and Roger Chaffee.
Sequence of Events
As the astronauts entered the Apollo spacecraft around 1:00 p.m. on January 27, 1967, problems immediately arose. When Gus Grissom entered the spacecraft and connected his oxygen supply, the first issue occurred. He noticed a smell in his space suit loop that had a "sour smell". The crew stopped to check the suit but after conversing with Grissom, they decided to continue on with the preflight test. The second problem was a high oxygen flow indicator which periodically triggered the master alarm. Once again, the test was halted. The pilots (astronauts) spoke with the environmental control system personnel who concluded that the sounding of the alarm resulted from their movement inside the cabin. The test continued without the issue being resolved. A third serious problem arose in communications. At first, faulty communications seemed to exist only between Command Pilot Grissom and the control room. Later, the problem extended to include communications between the operations and checkout building and the blockhouse at complex 34. This failure in communications forced a hold of the countdown at 5:40 p.m. By 6:31 the test conductors were about ready to pick up the count when ground instruments showed an unexplained rise in the oxygen flow into the spacesuits. It is then believed that Pilot Grissom moved slightly and just four seconds later, they smelled a fire. Procedures for emergency escape called for a minimum of 90 seconds. But, in reality, the crew had never accomplished the routines in the minimum time. To escape, Grissom had to lower White's headrest so White could reach above and behind his left shoulder to actuate a ratchet-type device that would release the first of series of latches. The module was simply not designed well enough for an emergency. It was too difficult to exit the cabin in time to escape any emergency that happened. This is the reason three astronauts perished that day. A medical board determined that the astronauts died of carbon monoxide asphyxia, with thermal burns as contributing causes. The board could not say how much of the burns came after the three had died. The fire had destroyed 70% of Grissom's spacesuit, 20% of White's and 15% of Chaffee's. Doctors treated 27 men for smoke inhalation. Two were hospitalized.
Physics Behind the Failure
In the Apollo 1 spacecraft, many problems occurred with the electrical wiring. Teflon, has an excellent fire resistance and was therefore chosen as the covering for the wiring in the spacecraft. However, the specific type of teflon used in the craft was easily damaged or penetrated by abrasion. If this wiring experiences penetration by a metal structure, a short is created at the point of conductor contact and becomes a high risk for a fire. Simultaneously, there was an Environment Coolant System leakage. This leakage left a highly combustible residue inside the cabin. These two problems together are believed to be the cause of the fire. Furthermore, there were combustible materials inside the module. This mainly consisted of a nylon netting to protect the equipment areas during ground tests. NASA knew nylon was combustible and therefore did not allow it for spaceflight. However, nylon was allowed to be used in the tests on the ground. This netting played a tremendous role in the rate at which the fire spread. The fire was able to spread rapidly throughout the cabin through the nylon netting. The last issue with the space craft was the design of the hatch doors. When the fire started, the pressure in the cabin began to build. With this pressure, it would be impossible to open a hatch that opens inward until the pressure was vented out of the cabin. If there was an easy access hatch, the outcome may have been drastically different.
Who is to blame?
Determined by the review board, the organizations responsible for the planning, conduct and safety of the test had failed to identify the situation as hazardous. It was also determined that there were issues in design, manufacture, installation, adjustments and quality control existed in the electrical, Environmental Control, and the communication systems. These problems were strongly influenced by governmental pressure to minimize cost and time and a lack of communication between NASA and these organizations.
Space exploration is considered a highly dangerous job field and because of this, safety is considered very important. The Apollo 1 disaster was the first major disaster that NASA encountered. After this disaster, much change took place and regulations were made to prevent an event like this to happen again. First, materials that are combustible must be strictly controlled both on missions and ground tests. Whenever possible, flammable materials must be replaced with non-flammable materials. Furthermore, a design of the cabin must be made where the crew can escape even under extreme pressure changes. Emergency personnel must also be readily available in case of emergency. The disaster of Apollo 1 really opened the eyes of NASA to see how important safety is. Safety should never be comprimised just to meet a deadline or to lower cost. Every aspect of a design now has safety built into it and the emergency preparedness is the number 1 goal from the time training starts to the very end of the mission.