This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
NASA’s Apollo program began with one of the worst disasters the organization has ever faced. A routine prelaunch test turned fatal when a fire ripped through the spacecraft’s crew cabin killing all three astronauts. Today marks the 45th anniversary of the Apollo 1 fire, a tragic and preventable accident. There were warning signs, similar accidents that had claimed lives both in the United States and abroad. The Apollo 1 crew could have been saved from a gruesome death.
Plugs Out
The commander for Apollo 1 was Gus Grissom, one of the original Mercury astronauts whose first spaceflight was marred by his capsule’s sinking after splashdown. He flew again in Gemini in a spacecraft he named “Molly Brown.” Senior pilot on the Apollo 1 crew was Ed White, a Gemini veteran who made America’s first spacewalk in 1965. Rounding out the crew was pilot Roger Chaffee, a talented rookie more than capable of holding his own with his experienced crew mates. He was a notoriously good guy who took pains to thank everyone for their contributions to Apollo right down to the janitors.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
By the end of January 1967, the crew was going through their final prelaunch tests; barring some major setback, they would make the first manned Apollo flight on February 21. One routine test NASA had done since Mercury was the “plugs out” test, a final check of the spacecraft’s systems.
The spacecraft was fully assembled and stacked on top of its unfuelled Saturn IB launch vehicle on pad 34. The umbilical power cords that usually supplied power were removed — the plugs were out — and the spacecraft switched over to battery power. The cabin was pressurized with 16.7 pounds per square inch (psi) of 100 percent oxygen, a pressure slightly greater than one atmosphere. With everything just as it would be on February 21, the crew went through a full simulation of countdown and launch.
A full launch-day staff of engineers in mission control also went through the simulation. The White Room, the room through which the astronauts entered the spacecraft, remained pressed next to the vehicle. A crew of engineers monitored the spacecraft and were just feet away from the astronauts.
Grissom, White, and Chaffee suited up and entered the Apollo 1 command module at 1pm and hooked into the spacecraft’s oxygen and communications systems. For the next five and a half hours, the test proceeded with only minor interruptions. Grissom’s complaint of a smell like sour buttermilk in the oxygen circulating through his suit was resolved after a short hold, and a high oxygen flow through the astronauts suits tripped an alarm. But these were minor problems and didn’t raise any red flags in mission control.
The real problem was communication. Static made it impossible for the crew and mission control to hear one another. An increasingly frustrated Grissom began to question how they were expected to get to the Moon if they couldn’t talk between a few buildings.
Just after 6:31 that evening, the routine test took a turn. Engineers in mission control saw an increase in oxygen flow and pressure inside the cabin. The telemetry was accompanied by a garbled transmission that sounded like “fire.” The official record reflects the communications problem. The transmission was unclear, but the panic was obvious as an astronaut yelled something like “they’re fighting a bad fire — let’s get out. Open ‘er up” or “we’ve got a bad fire — let’s get out. We’re burning up.” The static made it impossible to hear the exact words or even distinguish who was speaking.
But flames visible through the command module’s small porthole window left no doubt about what the crew had said. Engineers in the White Room tried to get the hatch open but couldn’t. It was an inward opening design, and neither engineers outside the spacecraft nor the astronauts inside were strong enough to force it open. The men in mission control watched helplessly as the scene played out on the live video feed.
Just three seconds after the crew’s garbled report of a fire, the pressure inside the cabin became so great that the hull ruptured. Men wrestling with the hatch were thrown across the room as flames and smoke spilled into the White Room. Many continued to fight their way towards the spacecraft but were forced to retreat as the smoke grew too thick to see through. In mission control, the telemetry and voice communication from Apollo 1 went completely silent.
An hour and a half later, firemen and emergency personnel succeeded in removing the bodies; Ed White was turned around on his couch reaching for the hatch. Over the next two months, the spacecraft was disassembled piece by piece in an attempt to isolate the cause of the fire. The full investigation lasted a year.
The Apollo 1 accident review board determined that a wire over the piping from the urine collection system had arced. The fire started below the crew’s feet, so from their supine positions on their couches they wouldn’t have seen it in time to react. Everything in the cabin had been soaking in pure oxygen for hours, and flammable material near the wire caught fire immediately. From there, it took ten seconds for spacecraft to fill with flames.
The crew’s official cause of death was asphyxiation from smoke inhalation. Once their oxygen hoses were severed they began breathing in toxic gases. All three astronauts died in less than a minute. Many who had tried to save them were treated for smoke inhalation.
The Chamber of Silence
The fire that claimed the lives of Grissom, White, and Chaffee is eerily similar to one that killed cosmonaut Valentin Bondarenko in 1961. Bondarenko was known to his colleagues as a congenial and giving man with great athletic prowess who worked tirelessly to prove he deserved the honour of flying in space.
Part of the cosmonauts’ training was done in an isolation chamber designed to mimic the mental stresses spaceflight. The room, which the men called the Chamber of Silence, was spartan to say the least. It was furnished with a steel bed, a wooden table, a seat identical to what they would have in the Vostok capsule, minimal toilet facilities, an open-coil hot plate for warming meals, and a limited amount of water for washing and cooking. The chamber was pressurized to mimic the capsule’s environment in space. In this case, the oxygen concentration was 68 percent.
During the test, cosmonauts would exercise mental agility with memory games using a wall chart with coloured squares. They would keep busy by reading or colouring — subjects were supplied with some leisure material. The silence was frequently interrupted by classical music to see how the subjects reacted to a pleasurable shock. Aside from these distractions, sensory deprivation inside the chamber was absolute. The room was mounted on thick rubber shock absorbers that muffled any vibrations from movement outside, and the 16-inch thick walls absorbed any sound. The cosmonauts communicated with doctors by lights. A light told the subject to apply medical sensors to his body, and a light outside the chamber signaled to doctors that they could begin their tests. A different light would signal the end of the isolation test.
The environment was designed to challenge the cosmonauts’ mental stability and adaptability. But the hardest part was that no subject knew beforehand how long his test would last. It could run anywhere from a few hours to weeks.
Bondarenko was the 17th cosmonaut to go into the Chamber of Silence and on March 23, his ten day test came to an end. A light signaled that technicians outside had started depressurizing the chamber to match the atmosphere outside. It was a routine part of the test, but this time it was interrupted by a fire alarm.
While he waited to leave the chamber, Bondarenko removed his biomedical sensors and wiped the adhesive off with rubbing alcohol on a cotton pad. In his haste to leave, and exhibiting the lack of concentration expected after ten days of mental testing, he didn’t look where he threw the pad. It landed on the hot plate’s coil. Cosmonaut Pavel Popovich theorized that he had been standing next to it at the time. Many subjects left the small heater on all the time to warm up the chilly room.
A fire sparked and spread in an instant; everything, including Bondarenko, was saturated with a high concentration of oxygen. Technicians wrenched the door open and exposed the chamber to air, killing the fire instantly, but the damage was done. Doctors pulled a huddled and severely burnt Bondarenko from the room. “It’s my fault,” he whispered when doctors reached him, “I’m so sorry… no one else is to blame.” The severity of the fire was immediately obvious. Bondarenko’s wool clothes had melted onto his body and the skin underneath had burned away. His hair had caught fire. His eyes were swollen and melted shut.
In Moscow, surgeon and traumatologist Vladimir Julievich Golyakhovsky got a frantic call at his office; the severely burned patient was on his way. Ten minutes later, a team of men in military uniforms arrived carrying the blanket-wrapped cosmonaut. They were accompanied, Golyakhovsky later recalled, by an overwhelming smell of burnt flesh.
Bondarenko pleaded for something “to kill the pain.” Golyakhovsky obliged and gave the patient a shot of morphine in the soles of his feet. It was the one unscathed part of his body thanks to his heavy boots, and the only place the doctor could find a vein. There was nothing he could do to save the man’s life. Bondarenko died the next morning. The official cause was shock and severe burns.
Lessons at Home
Parallels between the Apollo 1 crew’s and Bondarenko’s deaths are obvious, but how each space agency dealt with the deaths was very different. Grissom, White, and Chaffee were each given very public funerals in accordance with their respective military traditions. Bondarenko’s death was kept secret, his identity covered by a pseudonym. Not until 1986 did the world hear the true story of his death. This has bred speculation that had the Soviet system been more open, NASA would have know about the dangers of training in a pressurized pure oxygen environment and could have saved the Apollo 1 crew. Former cosmonaut Alexei Leonov even suggested that the CIA knew about Bondarenko since the US had pierced the Iron Curtain before the accident.
But this is unlikely. And besides, NASA wouldn’t need to look to the Soviet Union to know the dangers of testing in a pressurized oxygen environment. There were enough incidents in the US to make the danger very clear. Four oxygen fires in the five years before the Apollo 1 accident were proof enough.
On September 9, 1962, a fire broke out in a simulated spacecraft cabin at Brooks Air Force Base. The cabin was pressurized to 5psi with pure oxygen. Both subjects were protected by pressure suits. Neither sustained burns, but both were treated for smoke inhalation.
Two months later on November 16, four men had been inside the US Navy’s Air Crew Equipment Laboratory for 17 days in an environment pressurized to 5psi of 100 percent oxygen when an exposed wire arced and started a fire. It spread rapidly over the men’s clothing and hands for 40 seconds before they were rescued. All were treated for severe burns, and this was the only instance in which the source of the fire was identified.
Two Navy divers were killed on February 16, 1965 in a test of the Navy’s Experimental Diving Unit, which was pressurized to 55.6psi to mimic conditions at a depth of 92 feet. It was a multi-gas environment: 28 percent oxygen, 36 percent nitrogen, and 36 percent helium. Somehow, the carbon dioxide scrubbers that were designed to remove the toxic gas from the air caught fire. Pressure inside the chamber rose making it impossible for technicians outside to open the door and remove the men.
A 1966 oxygen environment fire came frighteningly close to anticipating the Apollo 1 accident. A fire broke out during an unmanned qualification test of the Apollo Environmental Control System on April 28. The cabin was pressurized to 5psi of 100 percent oxygen, just like the spacecraft would be in flight. The fire was blamed on a commercial grade strip heater inside the cabin and the incident was consequently dismissed. The commercial material would not be onboard any manned flights. The board that investigated the accident made no mention of the hazardous environment.
A Lack of Imagination
These accidents weren’t secret. NASA knew the dangers of a pressurized oxygen environment, which has prompted conspiracy theorists to suggest that the space agency intentionally put the Apollo 1 crew in danger. But this was hardly the case. In truth, no one at NASA gave much thought to a fire in the spacecraft.
In the early 1960s when Apollo was in its preliminary stages, a dual gas system (likely oxygen and nitrogen) was proposed for the crew cabin. This would have been safer in the event of fire, but more difficult overall. A mixed gas environment requires more piping and wiring, which in turn adds weight. Pure oxygen was simpler, lighter, and was already familiar to NASA. The dual-gas idea was scratched.
NASA did address the possibility of a fire in the spacecraft, but only developed procedures for an event in space when the nearest fire station was 180 miles away. Apollo, like Mercury and Gemini, had no specific fire fighting system on board. The 5psi of oxygen in space was considered too thin to feed a significant fire. Anything that could spark in that environment could be taken care of with a few well aimed blasts from the astronauts’ water pistol.
There was no procedure for a fire on the ground. With so many engineers on hand for every test, it was assumed that the astronauts would safe so long as fire extinguishers were nearby. But more importantly in the case of Apollo 1 is the plugs out test’s status: it wasn’t classified as dangerous.
Frank Borman, a Gemini veteran who would go to the Moon on Apollo 8, served as the astronaut’s representative to the Apollo 1 accident investigation board. He made this point about the plugs out test’s status abundantly clear. “I don’t believe that any of us recognized that the test conditions for this test were hazardous,” he said on record. Without fuel in the launch vehicle and all the pyrotechnic bolts unarmed, no one imagined a fire could start let alone thrive. Borman himself hadn’t thought twice when he went through the plugs out test before his Gemini 7 mission. He was confident in NASA and its engineers and stated on record that he would have gone through the Apollo 1 test had he been on the crew.
Borman alluded to the Apollo 1 crew’s shared confidence. There had been problems with Apollo’w development, and every astronaut had the right to refuse to enter a spacecraft. “Although there are sometimes romantic silk-scarf attitudes attributed to this type of business, in the final analysis we are professionals and will accept risk but not undue risks,” explained Borman. The Apollo 1 crew felt the dangers were minimal.
With that statement, Borman identified what he considered the crux of the problem and the real reason, however indirect, behind the death of the crew. “We did not think,” he said, “and this is a failing on my part and on everyone associated with us; we did not recognize the fact that we had the three essentials, an ignition source, extensive fuel and, of course, we knew we had oxygen.”
Gus Grissom serendipitously wrote his memoirs during the Gemini program. He addresses the inherent risk of spaceflight in the book’s final passage. “There will be risks, as there are in any experimental program, and sooner or later, inevitably, we’re going to run head-on into the law of averages and lose somebody. I hope this never happens… but if it does, I hope the American people won’t feel it’s too high a price to pay for our space program. None of us was ordered into manned spaceflight. We flew with the knowledge that if something really went wrong up there, there wasn’t the slightest hope of rescue. We could do it because we had complete confidence in the scientists and engineers who designed and built our spacecraft and operated our Mission Control Centre... Now for the moon.”
Though tragic, their deaths were not in vain. The substantial redesigns made to the Apollo command module after the fire yielded a safer and more capable spacecraft that played no small role in NASA reaching the moon before the end of the decade. It is a fitting tribute to the crew that the plaque on the pad where they perished reads “ad astra per aspera” — a rough road to the stars.
Suggested Reading:
- Official Apollo 1 site: http://www.hq.nasa.gov/office/pao/History/Apollo204/
- Colin Burgess and Rex Hall. The First Soviet Cosmonaut Team. 2009.
- Gus Grissom. Gemini. 1968.
- Apollo 204 Accident. Report of the Committee on Aeronautical and Space Science, United States. 1968. Available online: http://klabs.org/richcontent/Reports/Failure_Reports/as-204/senate_956/index.htm
- Report of the Apollo 204 Review Board to the Administrator, National Aeronautics and Space Administration. 1968. Available online: http://www.hq.nasa.gov/office/pao/History/Apollo204/content.html
- Hearings Before the Subcommittee on NASA Oversight of the Committee on Science and Astronautics. 1967.