As the fire spread, technicians rushed towards the capsule’s hatch in search of the necessary ratchet to open it.
They knew the capsule was pressurized with pure oxygen, which fuels fire. And they knew there were numerous combustible materials – from paper checklists and Velcro fastenings to nylon netting – within its walls that could ignite.
The Cause
Fire engulfed the spacecraft that would transport America to the Moon, creating a nightmare of flames and dense, choking smoke within its interior. Twenty-seven pad safety workers required medical treatment due to smoke inhalation.
Fire was started by an electrical spark from a bundle of wires attached to Grissom’s left couch, close to the environment control system. These had been placed there during an exercise aimed at testing how crewmembers could reach their cabin quickly in an emergency, yet were exposed to 16.7 psi pressure in space and therefore burned more rapidly than would occur on Earth.
White had his hands raised above his head and fidgeted with the hatch when the fire broke out, using a ratchet to loosen multiple bolts quickly before fire devoured his spacecraft, forcing its closure again due to cabin pressure. As fire consumed the capsule, astronauts struggled with opening it, only for it to close with tremendous force due to cabin pressure.
At least 90 seconds would have been needed for the crew to escape their capsule and reach the pad’s service structure, but their attempt was foiled by heat, intense smoke, and an explosive flash fireball emanating from their capsule. This flash fire destroyed their oxygen tubes as well as creating toxic gases such as carbon monoxide which asphyxiated them resulting in their deaths by asphyxiation.
Following the accident, Shea vowed that there would never be another “deliberately unsafe system,” but was concerned that NASA was prioritizing speed over safety. A month prior to the disaster he ordered that nylon nets replace steel netting used during tests in catching items dropped during tests; by this point the spacecraft had already fallen behind schedule by two weeks and its engineers did not have sufficient time to repair everything they desired to.
The Symptoms
Fire was blazing as astronauts struggled to open their capsule’s hatch, which had been sealed shut due to high cabin pressure caused by pure oxygen atmosphere and an inflexible door design that made it hard for them to open it. Heat and smoke filled their spacesuits as their oxygen tubes had either melted away completely or become partially blocked from heat-generating elements in their surroundings. They had little chance of escape.
Grissom became more disoriented as the fire spread throughout his cockpit and he struggled to remain conscious, his last transmission sounding as though he were screaming. Pad safety teams rushed to White Room in spite of dense smoke to try opening hatch; they needed a ratchet tool to release multiple bolts from complex latch system; however, time was running out as they also feared fire might ignite solid fuel escape rocket above capsule, creating even greater havoc.
Once a fire began–most likely by electrical arcing on exposed wiring beneath Grissom’s couch–it spread rapidly. With the cabin pressurized with pure oxygen to 16.7 pounds per square inch and fuelled by flammable materials in its command module, its flames spread fast. Nylon nets used to catch dropped objects as well as strips of Velcro added to its speed and intensity.
Within one minute, flames had quickly penetrated the capsule’s hatch and begun spreading across its interior, rivaled only by its rapid rate of combustion and accompanying pressure that quickly split its hull.
The review board’s report did not specifically pinpoint the cause of the fire, but did identify several contributing factors that made its effects worse. While acknowledging there were sound engineering reasons behind a complex hatch and pure oxygen environment, no single group took sole responsibility for monitoring these risks, while pressure of an expanding space program led some employees to work faster at the expense of safety considerations. Following the fire there was greater emphasis placed on safety; hatches were replaced with simpler designs; cabin atmosphere was no longer 100% oxygen; crew suits switched from nylon to beta cloth which are nonflammable – these changes had yet not fully come about prior to this disaster.
The Rescue
Virgil “Gus” Grissom had already participated in Mercury Seven and Gemini 4 flights before taking command of Apollo 1. His crew included senior pilot Edward H. White and rookie astronaut Roger Chaffee from the Navy who trained for spaceflight. At 1 pm they strapped in during preflight checks and rehearsals and bolted shut the three-piece capsule’s hatch containing pure oxygen to prevent decompression sickness; furthermore it contained stacks of paper checklists as well as plenty of Velcro fastenings and nylon nettings which all burned quickly in pure oxygen environments.
Mission Control immediately called Grissom; however, due to intense pressurization caused by the fire at LC-34, opening its inward-opening hatch would have been near-impossible; five minutes later the pad crew finally did open it–but too late.
As the cabin was consumed by flame, oxygen tubes melted, leading to asphyxiation for several astronauts and thermal burns from inhaling toxic gases; six hours after the fire started, rescue operations could only start after being delayed by waves of heat and thick grey smoke, something Pad Commander Don Babbitt described as incessant waves of heat and “very thick grey smoke.”
Review boards established after each Challenger or Columbia disaster determined no single system to be responsible, though poor design and construction of capsules and hatches, insufficient security during testing on launch pads and lack of fuel during launch were all identified as contributing factors to fires occurring later. While fire caused major delays to programs, it did refocus attention towards safety concerns at NASA – though probably not in such a way as to prevent future catastrophes such as those on Challenger and Columbia.
The Final Words
The fire that took the lives of Grissom, White and Chaffee is one of the darkest chapters in American history. It shook NASA’s confidence and threatened their ultimate goal of landing men on the Moon. While its exact cause remains unknown, its fatal conditions include 100% oxygen in an enclosed cabin which fed into a fire; flaws in design and construction of command module; use of flammable materials within astronaut suits and spacecraft itself; as well as an emergency hatch that couldn’t open quickly when necessary.
Three men died within five minutes, likely of physical burns or carbon monoxide poisoning. TV cameras at the launch pad showed their capsule engulfed by smoke and flames immediately after flames broke out; when crew members attempted to reach it but couldn’t, communications eventually went down until their last garbled transmission ended in pain-filled cry of death.
On the ground, as soon as the cause of the fire was known, panic ensued. Some blamed North American Aviation; others criticised NASA for pushing ahead with their mission despite precautionary steps that should have been taken. Tragically, this accident served as a painful reminder that no matter how well one may prepare themselves, there always exists the risk of something going wrong unexpectedly at any moment.
As a result of Apollo 1, many significant modifications were implemented into its design and operation. Pre-launch cabin atmosphere was altered from air only to oxygen/nitrogen mixture; all flammable material in spacesuits and capsule was removed; hatch was changed into single piece that could open easily with just the push of an astronaut’s finger;
NASA was also inspired by this fire to place greater emphasis on safety training for all astronauts, though no amount of training would have prevented Grissom, White, and Chaffee’s deaths from the fire that consumed their station. Still, training helped ensure that future missions would not be as risky; eventually this tragedy caused NASA to reconsider their Apollo program, leading them to finally land men on the Moon.