As the Apollo 11 mission began its descent toward the lunar surface,
astronaut Neil Armstrong’s heart pumped at a mere 75 beats per minute...
just in line with the average American sitting on their couch back home.
The astonishing calm wouldn’t last, however...
Shortly before touching down, the Lunar Module filled with alarms as the crew overshot their
designated landing point, and the craft began to run out of fuel. Armstrong would have to
take over manual control, with the fate of the mission and the hopes of millions in his hands.
The adrenaline would push Armstrong’s heart rate to 150.
And then, with the hard part of the way, Armstrong could relax slightly.
About to become the first man to step onto another world, his heart beat at 125 beats per minute.
The story of Apollo 11, as seen through the heart rates of its astronauts, is incredibly fascinating
and provides an untold behind the scenes glimpse of the mission to put the first man on the Moon...
A Healthy Crew
NASA took the health of the Apollo 11 crew exceptionally seriously.
Several clinical practices were followed before launch
to avoid inflight illness during a critical phase of the mission.
Before Apollo 11, the Mercury and Gemini programs were useful for improving the
safety of future crews. For this, scientists kept an eye on the astronauts’ cardiopulmonary
status - looking out for any sort of decreased exercise capacity,
loss of red blood cell mass, or cardiovascular deconditioning.
During the Apollo program, NASA was interested in minimizing any additional lunar health hazards,
including possible back-contamination from the Moon’s surface.
Onboard the spacecraft was bio instrumentation that monitored the vital signs of the crew.
This equipment could help ground-based flight surgeons rapidly identify any
physiological difficulty the men were going through.
The heart rate, oxygen consumption, and the inlet and outlet temperature of the
liquid-cooled garment worn by the crew were monitored continuously.
The bio belt in the garment could also return electrocardiograms,
respiratory patterns, and rate data.
Launch
The Apollo 11 mission was launched from Cape Kennedy on July 16th, 1969. Its objective was to
perform the first crewed lunar landing in history and return to Earth. Aboard were Commander Neil
Armstrong, Command Module Pilot Michael Collins, and Lunar Module Pilot Edwin “Buzz” Aldrin.
During the launch, the crewmen experienced four times the force of Earth’s gravity.
To withstand this, they lay on their backs with their legs elevated.
Armstrong was considered one of the best pilots in the United States.
He had survived feats like ejecting from a fighter jet, an experience he described as [QUOTE]:
“If all his body parts had been squeezed into the space the size of a bread box.”
During his training, the astronaut had also ejected from a lander simulator
and crashed into the ground three seconds later.
As far as heart-racing experiences go, he had experienced them all.
His heart rate was controlled for someone who was making history aboard a spacecraft.
Thirty-six minutes after launch, NASA informed the public that Armstrong had a heart rate of 110
beats per minute. Collin’s was 99, and Aldrin’s 88. Aerospace experts agree that Armstrong’s was
higher because he was the mission leader. His adrenaline must have been through the roof.
The typical heart rate of a person ranges from 60 to 100 beats per minute.
However, their heart rates were within what was expected from experienced astronauts.
The three of them had been to space before through the Gemini program,
and their heart rates after launch had actually been higher then.
During most of the trip to the Moon and back, Armstong’s average heart rate was 71,
Aldrin’s was 67, and Collins’ was 60.
This was incredible; these stats proved the men stayed mostly calm during their mission in space.
John Charles, a retired NASA scientist, said to The Atlantic [QUOTE]:
“Whereas you and I would say, ‘Oh my god, I’m on top of a 300-foot-tall rocket full of
liquid hydrogen that could blow us sky-high,’ for them, it’s like, ‘I’m going to work.’”
Descent
Two hours after launch, Apollo 11 went into translunar orbit.
During this loop, the command and service module was supposed to dock with the lunar module,
known as Eagle. Collins was to stay behind in the command module, which served as their
living quarters. At the same time, Armstrong and Aldrin went into the lunar landing craft.
Mission Control kept a permanent watch on the Astronauts until July 19th,
when they looped around the Moon’s far side. As Apollo 11 lost all contact with Earth,
Armstrong’s heart rate was 106, Aldrin’s 70, and Collins’s was 66.
Then, one of the most challenging parts of the mission began: the descent onto
the lunar surface. No simulation could prepare them for the first actual landing on the Moon.
The crew depended on a computer system responsible for landing the Eagle, the 33,000-pound lunar
module. The Astronauts felt the Moon’s gravity tug as they made the descent on the Eagle module.
Space journalist Jay Barbree described the moment [QUOTE]:
“Their arms sagged. Legs settled within their suits.
Their feet pressed downward in their boots as they yielded to their down-rushing speed.”
Suddenly, the alarms of the Eagle blared. The module was off course by four miles.
Instead of landing on a flat surface, they saw a crater with boulders ahead of them.
Then the low-fuel light turned on. The 1202 Program Alarm also went off,
indicating that the computer was trying to do too many things at once.
These circumstances were reason enough to abort the mission prematurely.
But Mission Control found no actual malfunction. They told Armstrong
to carry on and manually land the module instead of relying solely on the autopilot.
Armstrong’s heart rate was at 150, the second-highest of the trip,
while manually flying the lunar lander with partial computer system assistance.
He trusted that, even if they ran out of fuel, he’d be able to land thanks to the
tug of Moon’s gravity. But he only had 94 seconds to decide whether to land or to abort the mission.
He was also standing up, which must have made him feel Moon’s gravity’s effects more strongly.
According to NASA experts, the physiological factors, paired with the three-second delay in
communications with Earth, must have sent his heart racing with stress.
Amidst enormous tension, Armstrong finally drew the Eagle away from the crater and onto a flat
surface, successfully landing the module on the Sea of Tranquility. His heart rate started
rapidly decreasing, a sign that his comfort level was increasing. Relaxed after landing,
he famously said, [QUOTE]: “Okay. Let’s get on with it.”
Exploration
Before the descent, Armstrong and Aldrin took Lomotil to delay their bowel movements.
They were also supposed to take a four-hour nap, but they felt well-rested enough to
carry on with their mission. For a few hours after landing, both men stayed in the module,
acclimatizing to the gravity of the Moon.
When Armstrong took his historic first step into the Moon, his heart was racing at 125 beats per
minute. On average, his heart beat faster during landing than while actually exploring the Moon.
The astronauts’ mission was to gather a
sample collection and transfer sample return containers in only 10 minutes.
But completing their tasks while bouncing around in their spacesuits wasn’t easy.
NASA experts have pointed out that moving around in the suits required significant
amounts of energy from the astronauts. The gloves didn’t allow for much hand dexterity, either.
As Armstrong hurriedly bounced to take a panoramic picture of a crater, his heart
rate jumped to over 140. While loading sample containers into a pulley system,
he actually reached the highest heart rate of 160.
This increase in his heart rate worried Mission Control, who wanted Armstrong to slow down.
So they sent a message asking for an update on his life-support systems,
which managed to distract him for a few seconds.
Back to Earth
After collecting the necessary pictures and samples, Armstrong and Aldrin went back
into the Eagle. As they slept, Mission Control reported their heartbeats had gone down to 50.
This indicated the crewmen weren’t sleeping but rather dozing.
From inside the module, the astronauts could see Earth shining just like a bulb light.
It was no surprise that the men couldn’t sleep. Smelly moon dust had stuck to their suits and
made its way into the module. Even if they could remove it from their skin, it was still
stuck under their nails. Moreover, inside the module, they had no beds or places to sit on.
The room temperature was cold, and the machines made an incredible amount of noise.
The next day, the Eagle was back into orbit, and the module docked with the
command system to return home. Armstrong’s heart rate rose to 120 and then went back down to 80.
During the trip back, the flight surgeon saw something alarming. Aldrin’s heart rate was at an
astounding 240. The astronaut joked to Houston [QUOTE]: “Well, I can assure you my heart’s
still working.” In reality, the sensors weren’t working because the adhesive part had dried out.
The flight surgeons were worried about two main health hazards for the astronauts. One of them
was that the astronauts would pass through the Van Allen radiation belt during the trip back to
Earth. This represented a significant radiation hazard that was thought impossible to survive.
However, the crewmen were only exposed from 0.25 to 0.28 Rad during a short period of time.
This is equivalent to getting a CT scan nowadays.
Another concern one was the unknown damage the moon dust under their nails could provoke.
There was fear that extraterrestrial microbes could cause diseases,
which is why the astronauts were to be quarantined for 21 days. However,
the lunar surface was sterile, and the men didn’t suffer any health issues after their mission.
Throughout the mission, the astronauts were extremely fit and healthy. Their hearts
rates have remained a testament to the excellent training they received before flying to the Moon.
A NASA mission report states [QUOTE]: “At no time during the exercise was there any heavy breathing.
For the most part, the astronauts’ heartbeat was lower than expected—lower,
in some cases, than that of those at Mission Control who were watching.”