The hell of Apollo 1: Pure oxygen, a single spark, and death in 17 seconds

The crew of Apollo 1 crosses the gantry to the spacecraft on the day of the fire, Jan. 27, 1967.
NASA
On a gray January afternoon in Houston,
Walt Cunningham leaned into his Eames Lounge Chair and clasped his hands
behind his head, the better to try and bend his thoughts back across
five decades. Floor-to-ceiling windows let in a dull light that outlined
Cunningham; it was a gloomy backdrop that mirrored the Apollo
astronaut’s melancholy mood.
As a backup crew member for the initial Apollo
mission, Cunningham recalled clambering into the first Apollo capsule
on Jan. 26, 1967 for some pre-flight work. All had gone well, and no one
thought the next day’s test, when the capsule would rely on its own
internal power for the first time, would prove fatal. “We always
expected that we’d lose at least one mission before we landed on the
Moon, because of how far we were reaching out,” he said. “But we didn’t
expect it to be on the ground.”
The Apollo astronauts, most of them cocksure
test pilots, were accustomed to risk. In those early days as NASA
invented spaceflight on the fly, all of the vehicles had flaws. The
early astronauts trusted that they could handle any situation that came
their way. “Rightly or wrongly, we thought we were going to be good
enough to compensate for whatever it was,” Cunningham explained.
But, infamously, a fire in the pure oxygen
environment of the Apollo 1 spacecraft could not be compensated for—even
by arguably NASA's best test pilot, Gus Grissom, veteran astronaut Ed
White, and rookie Roger Chaffee. Just seconds after a spark ignited
inside the capsule, a conflagration burned hotter than 1,000 degrees
Fahrenheit. As materials inside the spacecraft were incinerated, they
gave off toxic fumes. Opening the spacecraft’s cumbersome hatch, under
the best of circumstances, required a minimum of 90 seconds.

Cunningham speaks during the 40th anniversary of the Apollo 11 mission in 2009.
NASA
The aftermath of the grisly accident found
America questioning its previously infallible space program, which since
the late 1950s had chased, caught, and surpassed the Soviet Union in
the race to the Moon. Ultimately, however, the Apollo 1 fire probably
saved NASA’s lunar ambitions. The fire forced a hard reset of a space
program that had been rushing headlong toward the Moon, but had lost its
way due to overconfidence. A better Apollo capsule was born from the
accident.
“I’m always asked if I was nervous about that
flight,” said Cunningham, the lunar module pilot on Apollo 7, which
marked NASA’s return to flight after the accident. “We never really had
any doubts. Everybody was working to get us there. Thousands of people.
We were sitting at the end of the arrow so we got the glory, but those
other people had the same attitude we did—if this mission fails it won’t
be because of me.”
Oxygen and wires
To understand the whirlwind in which NASA
existed in the mid-1960s, consider that Gordon Cooper flew the final
Mercury mission in May 1963. Then, in March of 1965, the first Gemini
crewed mission launched, beginning a series of tests in low Earth orbit
that would prove the technologies needed to go to the Moon. Several
months before that Gemini flight, however, technicians cut the first
metal on Apollo flight hardware, known as Spacecraft 012. Amazingly,
this was NASA’s third new spacecraft in just five years. In the 51 years
since, NASA has flown just one other crewed spacecraft: the Space
Shuttle.
During 1966, NASA flew five Gemini missions.
Yet even amid this hectic schedule, engineers with the agency
confidently conducted final design reviews on the Apollo capsule. In
August, the agency took delivery of Spacecraft 012 at Kennedy Space
Center. Its maiden launch was planned for February 1967.
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The crew of Apollo 1: Veteran astronaut Gus Grissom (left), first American spacewalker Ed White, and rookie Roger ChaffeeNASA
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Chaffee (left), White, and Grissom inside the mission simulator. This provides a view of cramped quarters inside the capsule.NASA
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In August 1966, the Apollo 1 crew expressed their concerns about their spacecraft's problems by taking this "prayer" photo and then giving it to Joe Shea, manager of the Apollo Program office.NASA
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Manufactured by North American Aviation, the Apollo 1 command module arrives at Kennedy Space Center in August 1966.NASA
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Practicing water egress procedures in a swimming pool at Ellington Air Force Base in Houston, Texas. Ed White rides a life raft in the foreground, Chaffee sits in hatch of the mode spacecraft, and Grissom waits inside the spacecraft.NASA
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The Apollo spacecraft Command Module for the AS-204 mission is shown during preparation for installation of the crew compartment heat shield.NASA
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Grissom, White, and Chaffee enter the Apollo Command Module during training in the days before the fire.NASA
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The Apollo 1 crew two days before the fire.NASA
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A rare image of the Apollo crew on Jan. 27, 1967.NASA
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Another one.NASA
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The crew of Apollo 1 crosses the gantry to the spacecraft on the day of the fire, Jan. 27, 1967.NASA
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Apollo 1's Command Module, a day after the fire.NASA
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Grissom's coffin. Fellow astronauts (left to right) Alan Shepard, John Glenn, Gordon Cooper, and John Young serve as escorts.NASA
McDonnell Aircraft had won NASA contracts to
construct the Mercury and Gemini capsules, but the Apollo award went to
North American Aviation. This well regarded company had earned plaudits
for the X-15, a hypersonic, rocket-powered aircraft that had flown as
high as 107.8km in 1963, crossing the threshold into outer space.
Nevertheless, although North American had much experience with
airplanes, it had little with actual spacecraft.
In the early days of the capsule’s design,
engineers at NASA made another critical—and ultimately fatal—decision.
Knowing full well the premium on weight in a spacecraft launched from
Earth to the Moon in a single stack, managers looked for every
opportunity to trim mass from the capsule and three-stage rocket. A pure
oxygen atmosphere was one option, as it required a lighter
environmental control system to produce than a more complex mix of
nitrogen and oxygen.
The risk, of course, is that pure oxygen under
high pressure requires but a spark to ignite and rapidly burn. However,
because a pure oxygen atmosphere had worked without incident for the
Mercury and Gemini capsules, NASA decided it would be safe to press
ahead with the same for the larger Apollo capsule.
The new spacecraft was more complex, with
considerably more electronic equipment inside. The initial version of
the spacecraft contained more than 600 switches, indicators, and
computers, all of which had to be connected and powered by an extensive
amount of wiring. In his biography Forever Young, A Life of Adventure in Air and Space,
the Gemini, Apollo, and Space Shuttle veteran John Young recounted the
unfortunate differences in wiring between the Gemini and Apollo
spacecraft.
To save on labor costs, North American had
used machines to bundle the miles of wires that snaked through the
Apollo spacecraft, the arrangement of which seemed arbitrary to Young.
Some wires even appeared frayed. As he surveyed the capsule that
Grissom, White, and Chaffee were to fly in, Young saw a seemingly
endless amount of short circuits. “I knew it when I saw it, and I saw it
in spades in the command module,” he wrote.
In the hurly burly world of NASA at the time,
however, such a problem hardly stood out with the imperfect vehicle.
Spacecraft 012 had shipped from California to Florida with more than 100
“significant” engineering orders still not completed, according to the
accident report. For the astronauts, if they complained too loudly,
there was also the threat of getting pulled off the mission.
“While Grissom complained long and loud behind
the scenes about many of the problems with his spacecraft, he likely
tolerated the bad wiring because he, NASA, and its contractors were at
that time firmly in the grip of a deadly malady called ‘Go Fever,’”
wrote George Leopold in his recently published book on Grissom’s life, Calculated Risk.
“Grissom and his crew were gambling that the growing list of problems
with the spacecraft would somehow be fixed in time for the February
launch.”
The hell of Apollo 1: Pure oxygen, a single spark, and death in 17 seconds
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