57 years ago, we went to the moon.
>> That's one small step for man, one giant
leap for mankind.
>> This 21-hour and 36-inute visit to the
moon changed the face of science
forever, spawning 150 articles in one
scientific journal alone in the 6 months
after the astronaut's return to Earth.
>> Got it. Sample. But what appeared to
many like an effortless feat was not all
plain sailing. This mission nearly
failed and not just once.
So, what did the Apollo 11 astronauts
find on the moon and how did they defy
all the odds and make it home?
I'm Alex Mccoan and you're watching
Astrome Extra. Join me today as we dive
back into the Apollo 11 mission for part
two of this incredible voyage to the
moon and back. In part one, we got our
astronauts safely to the lunar surface.
But now, it's time to get to the bottom
of what they found and how they made the
deadly trip home.
The 20th of July, 1969.
For the first time in human history, we
were about to walk on another world. The
astronauts had left the safety of Earth,
traveled 384,400
km across space, and split their
spacecraft. Mike Collins was left
circling the moon in the command module,
whilst Neil Armstrong and Buzz Aldrin
touched down on its surface in the lunar
module. All that was left was to take
one small step.
But that meant leaving the protective
walls of the lunar module and exposing
themselves to a place of lethal
extremes, harsh temperatures, deadly low
pressures, UV radiation, and high
velocity micrometeors.
To survive, Armstrong and Uldren
required more than just clothing. They
essentially needed a wearable
spacecraft.
Enter the Apollo A7L.
Its first and most critical task was
preventing the pair from literally
boiling to death in seconds. You see, in
the near vacuum of the moon, without
atmospheric pressure, water, including
water in your blood, boils at body
temperature. To counter this, the A7L
needed to be pressurized. And this was
done using three bits of kit. First was
the pressure bladder, an airtight
rubbery layer designed to hold a pure
oxygen atmosphere. Think of it as a
human-shaped balloon. But a balloon
under pressure expands. Too much would
make any movement pretty much
impossible. That's where the resistant
layer came in. A high strength nylon
wrapped tightly around the bladder,
reinforcing it and maintaining the suits
shape. This exoskeleton prevented the
suit from bursting or ballooning,
allowing the astronauts to actually bend
their limbs. Pretty useful considering
they had a lot to do. Finally, there was
the portable life support system or
PLSS.
The iconic backpack was a masterpiece of
1960s miniaturization. It was the source
of the astronaut's oxygen, not only for
breathing, but also for maintaining an
internal pressure of roughly 3.9 PSI.
That's only a quarter of the pressure at
sea level on Earth, but enough to keep
astronauts alive. So, that was the
pressure dealt with, but what about the
moon's vast temperature swings? As we
know from last time, the moon's thermal
environment is one of the most violent
extremes, plummeting to minus 133° C in
the shadows, yet soaring to 100° in the
sunlight. This suit needed to be ready
for anything, and material scientists
and seamstresses prepared for this by
using layers, and a lot of them. The A7L
had 21 layers in total, made from a mix
of 12 different synthetic materials.
Most of these were in the outermost
garment called the thermal meteoroid
garment or TMG.
To be effective over the large heat
range inside the TMG, they had to use
layers of two different materials,
aluminiz captain and myar, both of which
insulated the suit and reflected away
the sun's heat. By using both, the suit
benefited from Myar's superior
lightweight insulating efficiency and
Capton's exceptional strength and
temperature resistance. Meanwhile, the
outer beta cloth, a tefloncoated glass
fiber, provided a white reflective
shield against radiation and abrasive
lunar dust. What I'm about to say next
will sound very strange. The astronauts
also needed protection from their own
body heat. On the moon's surface, they
were essentially working out, but there
was no way to remove a layer to cool
down. So to prevent this trapped heat
becoming deadly, NASA developed a liquid
cooling garment worn against the skin.
This network of tubing circulated cold
water, wicking away heat, ensuring the
astronauts didn't collapse from heat
stroke. It wasn't just the heat that was
a problem, though. It was the invisible
radiation that came with it. Without an
atmosphere, the astronauts were exposed
to a constant barrage of intense
ultraviolet and infrared light.
Protecting against this led to one of
the mission's most iconic features, the
goldplated helmet visor, a 0.0000508
cm or 50.8 8 nanometer layer of real
gold was applied to a polycarbonate face
shield and acted as a high tech mirror.
But why gold and not silver or
aluminium? Well, gold is stable, so
won't oxidize or tarnish, and it's easy
to work with, enabling engineers to
create a thin, unbroken layer across the
visor. Beyond its protective qualities,
it functioned as the ultimate pair of
sunglasses. dampening the blinding solar
glare to allow the astronauts to
actually see their surroundings. In
fact, gold is so good at filtering
infrared and UV light that the moon's
surface would have appeared slightly
more blue or green to them, not entirely
gray like in the photos. All in all, the
golden visored astronaut suit became one
of the most iconic aspects of the Apollo
mission. a visually eye-catching
engineering marvel that has remained a
part of the public imagination to this
day. Most businesses would love to have
the level of recognizability that these
suits have. But if you're a business
chasing the public's attention, you
don't need a team of NASA engineers. You
need the right website. And you can
suits needed to survive more than just glare from the sun or body heat. Beyond
these invisible dangers lurked yet more
threats, this time of a more ballistic
nature, micrometeoroids.
The moon is pelted by roughly 1,270
kg of space debris every single day,
traveling at speeds of up to 20 km/s.
Even a speck of dust can carry the
kinetic energy of a bullet. And there's
no atmosphere to burn up this debris
before it hits the surface where an
unlucky astronaut may be standing. To
counter this, the suit's outer shell use
something usually found built into
spacecraft, a whipple shield design.
This is basically a series of high-tech
materials arranged in specific layers to
help absorb serious impact. In this
case, the outer materials were
tefloncoated beta cloth and high
strength dacron that would shatter any
high-speed projectile that hit it. While
the inner layers of myar and yet more
dacron acted as cushions, absorbing and
dissipating the remaining energy,
spreading the force of the impact over a
wider area ensured that the critical
pressurized inner bladder remained
unpunctured, keeping the vacuum of space
at bay.
safely encased within these portable
sanctuaries, Neil Armstrong and Buzz
Aldrin survived those first iconic
steps.
But the celebration was short-lived. A
grueling checklist of lunar science lay
ahead and they only had 2 and 1/2 hours
to complete it. It was a race against
the clock.
The top priority was getting a lunar
sample. Within minutes of stepping off
the eagle's ladder, Armstrong collected
a small amount of regalith and tucked it
into a pocket on his leg. This ensured
that even if an emergency forced an
immediate evacuation, they would not
return to Earth empty-handed.
But the true scientific payload lay
within the early Apollo scientific
experiments package, a 48.5 kg suite of
scientific experiments that you can see
Buzz carrying here. One of the key
instruments was the laser ranging
retroreflector.
This simple array of quartz prisms
allowed scientists on Earth to bounce
laser beams off the moon's surface with
incredible precision. By timing the
round trip of these photons, we could
measure the distance between our two
worlds within a few millime. And
measurements taken using the
retroreflector throughout the 1970s
helped us discover that the moon is
slowly drifting away from Earth at a
rate of about 3.8 cm per year. And
incredibly, these measurements continue
to this day using that same retro
reflector for gravitational wave
research, most recently in 2026 by the
Tianin laser ranging station in China.
The other large experiment was a
seismometer used to measure ground
motion. This device and the others
placed after it revealed that the moon
was not a dead solid rock. Instead, it
vibrated with moon quakes. These are
similar to earthquakes and are formed
through four different methods. The deep
ones hundreds of kilome beneath the
surface are tidal caused by the pole of
Earth's gravity tugging and stretching
the moon's internal structures. The
shallow ones originate just 20 to 30 km
down, can last up to 10 minutes, and are
caused by the moon shrinking as it
cools. And finally, there are two types
that start on the surface. One caused by
meteor impacts, and the other by the
heating and cooling of the moon's crust
as it cycles between night and day. And
that one's not ideal for any future
lunar base. The final scientific task
that needed to be completed was
collecting samples. In total, the crew
collected 21.5 kg of lunar material,
basaltic rocks, and fine dust that had
remained undisturbed for billions of
years. Because they had not been
contaminated by life and were
essentially unchanged since their
formation, these specimens became our
golden record of the solar systems
history, containing chemical signatures
of early Earth and the violent impacts
that shaped our celestial neighborhood.
After 2 hours 31 minutes and 40 seconds,
time was up. Uldren and Armstrong
reclimbed the ladder and the hatch of
the lunar module swung shut. The
astronauts had made it, pushing the
limits of their life support backpacks.
Despite having 4 hours worth of air,
NASA seleated their sorty to only be 2
and 1/2 hours long in case of other
emergencies. The astronauts left behind
their tools and footprints, and they
carried back something far more
precious. The chemical keys to our solar
systems origin.
Yet, the victory was only half won.
Exhausted and covered in sticky,
electrostatically charged moon dust,
they now faced the ultimate gamble. All
that was stopping them from dying a
lonely death on the lunar surface was a
single untried engine.
On the moon, there are no rehearsals and
no hope of rescue should anything go
wrong. The lunar module had 73 hours of
oxygen, but that was nowhere near long
enough to survive a resupply mission all
the way from Earth. To get home, the
Eagle had to intercept the command
module. A tiny moving target racing
through the blackness at over 5,000 kmh.
Missing this window by even a few
seconds would mean drifting into a
useless orbit or possibly worse,
depending on how you see it, falling
back towards the surface.
In an environment with no atmosphere to
provide aerodynamic lift, the crew was
entirely dependent on physics. Guiding
them was the LGC, the lunar guidance
computer. Its job was to outsmart the
moon itself, calculating precise engine
burns while accounting for masscons,
hidden concentrations of dense rock
beneath the lunar surface whose uneven
gravity could tug the spacecraft off
course.
At 124 hours and 22 minutes into the
mission, countdown hit zero. The Luna
module carried out a vertical rise for
around 8 seconds, followed by a dramatic
pitch over to nearly 50°. This tilt
allowed the ascent engine to push the
craft downrange, gaining the horizontal
velocity needed to reach orbit. Because
the moon's gravity is only 16 that of
Earth's, the ascent was feasible with a
single non-throttleable engine, but it
required total precision. After the
continuous burn, the Eagle achieved an
initial elliptical orbit of roughly 17
by 87 km, exactly as planned. The moon
was behind them, but safety still lay
many kilome away.
Their next task was to connect with the
command module. But how do you do that
when you're traveling at more than 5,000
kmh and a single degree of error could
kill everyone involved?
An hour after liftoff, the Eagle's
thrusters fired in a sequence known as
the co-alyptic sequence initiation.
This circularized its path, bringing it
onto a parallel track with its mother
ship. From here, the Eagle's hunt for
the command module began.
2 and 1/2 hours later, the gap was
closing. At 72 km out, the Eagle
performed its terminal phase initiation,
a precise burn designed to help it
intercept its target. Roughly 10 minutes
later, through the narrow triangular
windows, Neil Armstrong caught his first
glimpse of the command module Colombia.
All that was left was to connect it.
You might think this would be a simple
task for elite test pilots, but in the
vacuum of space, your eyes are your
enemy. Without an atmosphere to provide
haze or clouds to give a sense of scale,
your death's perception vanishes. And in
a realm where it is simultaneously
blindingly bright and pitch black, the
shadows lie to you and distances become
impossible to judge. This is why despite
the combined 40 years of flying
experience, the main rendevous was
assigned to a digital computer. It
worked by Eagle's radar pinging out into
the void and Colombia's transponder
pinging back. This data fed the Eagle's
primary guidance navigation and control
system, nicknamed the pings computer,
allowing the machines to handle the
high-speed geometry of the approach
while the humans kept an eye on the
instruments.
Only in the final moments, once their
velocities were perfectly matched, did
Armstrong and Collins take control to
fly towards each other by eye. But their
margin for error was zero.
Thankfully, at 2135 UTC,
the command module's triangular probe
clicked into the lunar module's
receiving conicle drogue, triggering
three capture latches. As they pumped up
the cabin pressures, the 12 latches
around the docking ring engaged and
created an airtight, pressuretight seal.
Uldren and Armstrong were finally safe.
A few moments later, they were reunited
with Michael Collins, who had been
orbiting the moon alone the whole time.
But there was no time for celebratory
dance or high fives. Instead, they
quickly began unloading their precious
cargo. Before long, the trusty LM was
released from the command module,
remaining behind in lunar orbit.
Now, all that was left was for the crew
to make the 2.5day,
384,400
km journey home. Something that was
easier said than done.
With every passing hour, Earth grew
bigger and bigger in their windows,
offering a tantalizing glimpse of home.
But with the main aspects of their
mission accomplished, they could finally
turn their attention to a rather
unsettling phenomenon they had all been
experiencing.
When they closed their eyes in the dark,
the astronauts saw something strange.
Brilliant flashes of light that
shouldn't have been there. Buzz Aldrin
later described them as spots, streaks,
and supernovas. He recalled the crew
fearing they might be signs of their own
fatigue or more worryingly a failure in
the spacecraft's engineering. Luckily,
in 1952, a physicist called Cornelius
Tobias had predicted this very issue. He
had been largely ignored. That is until
the astronauts started reporting these
phenomena. Tobias theorized that outside
the protection of Earth's magnetic
field, high energy subatomic particles
would collide directly with the
astronaut's eyes. As the particle passed
through the fluid of the eye called the
vitrius humor, faster than the speed of
light in that medium, it would create an
optical sonic boom that would appear as
a faint blue glow called Tenov
radiation. Whilst the bias was not
proven definitively right until 3 years
after the Apollo 11 mission, these first
observations sparked a wealth of
research into this phenomenon across the
subsequent Apollo missions. But even as
the crew peacefully rested amidst the
flicker of cosmic rays, they were
accelerating into a lethal trap. At more
than 39,000 kmh, the Earth's atmosphere
loses its softness. hit it at the wrong
angle and the air becomes as solid and
unforgiving as a wall of stone. So, how
were they planning to get through? The
crew safety rested on two things. The
path the mathematicians had mapped out
and the armor the engineers had
provided, creating a vessel strong
enough to survive the journey home.
First up, the maths. Colombia had to hit
an area in the sky known as the entry
corridor. The target was a precise angle
of 6.5°
relative to the horizon. The margins
were unforgiving. If the angle was too
steep, anything over 7.7°,
the capsule would dive too deep, too
fast, and friction would generate
temperatures far beyond the heat
shield's limits. The deceleration would
hit the crew with crushing high G's of
force. All in all, not ideal, as the
ship would likely incinerate.
But if the angle was too shallow, under
5.3°,
the atmosphere would act like the
surface of a pond, the capsule would
jump off the heavy air like a skim stone
and be flung back into an elliptical
orbit. Whilst this doesn't sound too
bad, you have to remember that the
service module, the part of the ship
that supplied the oxygen, was planned to
be jettisoned just before re-entry. So,
the crew would be trapped, drifting in a
silent orbit, slowly suffocating to
death. But even with a safe path through
the corridor calculated, the journey was
anything but a gentle descent. The crew
still had to contend with white hot
2,700
degree temperatures and crushing
G-forces that pushed their human bodies
to their absolute limits. These forces
had to be absorbed and NASA engineers
had built the answer directly into the
bones of the command module. Starting
off with its shape, unlike a sleek
missile, the command module was a blunt
cone. This was a deliberate piece of
hypersonic wizardry discovered in the
1950s. By being unerodynamic,
the air did not flow around the capsule
easily. Instead, it compressed the air
in front of it, creating a detached
shock wave out ahead of it. This massive
wall of air acted as a buffer, forcing
the most intense heat to flow around the
vehicle rather than into it. The heat
that did touch the ship was met by one
of the most sophisticated substances
ever devised. Avote 502639,
a low density ablated heat shield
material arranged into tiles that
covered the bottom of the craft. This
was no simple tile. It was a resinfilled
fiberglass honeycomb that functioned
through a process called ablation. As
the avote heated up, the material
chemically decomposed, charred, and then
flaked away, physically carrying the
thermal energy away from the spacecraft.
But for this sacrificial chemistry to
work, the shield had to be flawless.
This wasn't a mass- prodduced component.
It was a delicate mosaic. The Avco resin
was injected into the structure
consisting of more than 300,000
individual cells. Any tiny air bubble or
gap could lead to a catastrophic burnth
through during re-entry. So the
application had to be perfect.
This perfection was not achieved by
machines. But sheer human persistence
which continues to this day. Armed with
specialized tools that looked like
industrial culking guns, teams of
technicians filled every single cell one
by one by hand. After each cell was
filled, the entire shield was x-rayed to
search for the slightest imperfection.
It was a process that took several
months for a single capsule. And the
result of this painstaking labor was a
masterpiece of thermal insulation.
While the outer shield glowed white hot
and disintegrated in a stream of sparks,
the aluminium pressure vessel and the
three men inside remained at a
comfortable room temperature just inches
away. That was the theory anyway. All
that was left was to actually do it.
Colombia slammed into the air at around
40,000 kmh. the friction stripping
electrons from the surrounding
molecules, creating a shimmering sheath
of ionized gas that blocked all radio
waves. In Houston, the consoles went
flat.
3 minutes. That was the duration of the
blackout, a period of harrowing silence
where the crew of Apollo 11 was encased
in a cocoon of superheated plasma,
unable to communicate with mission
control. Inside the cabin, the view was
apocalyptic.
The windows were filled with a chaotic
swirl of orange and neon green as their
heat shield disintegrated around them.
The crew were slammed into their seats,
crushed by a 6.5g
force. Roughly 20 km up, the fire
subsided and the radio crackled back
into life. Soon after the apex cover was
jettisoned and a pair of drove
parachutes snapped open to stabilize the
plummeting capsule. Then three iconic
orange and white parachutes unfilled,
slowing the near 5,000 kg craft from a
terminal plunge to a survivable 35.4 km
hour. 5 minutes later at 165035
UTC, Colombia hit the Pacific Ocean
around 1,527
km southwest of Hawaii splashed down.
They had survived the landing, but the
nearly 2 m high ocean waves they landed
into were less than hospitable.
Thankfully, one final piece of clever
engineering called the uprighting system
ensured they did not drown. Because the
capsule had an offset center of gravity,
it tended to settle in the water upside
down, leaving the astronauts hanging
from the ceiling by their seating
straps. To prevent this, what looked
like three giant yellow beach balls were
triggered by the crew to force the ship
to write itself. Now stabilized, all the
crew had to do was wait to be rescued by
boat. But as it happened, the ordeal was
not yet over. Even as the hatch finally
creaked open, the hero's welcome was
deferred. Because NASA scientists feared
that lunar dust might harbor unknown
pathogens that could devastate Earth,
the crew was not met by their families,
but by a biological isolation team. In
the middle of the Pacific Ocean,
Armstrong, Uldren, and Collins were
forced into biological isolation
garments, looking like silver aliens.
They were whisked away in a sealed
mobile quarantine van and eventually
locked in a high security lab in
Houston. Behind a thick pane of glass,
the men who had just conquered the
heavens spent their first 21 days on
Earth in a glorified cage, watching the
world celebrate their triumph from the
inside of a sealed room. Armstrong even
celebrated his 39th birthday in
quarantine, although the Luna receiving
lab kitchen staff did make sure he got a
cake.
We often remember the names Mike
Collins, Buzz Aldrin, and Neil
Armstrong. But Apollo 11 was carried by
an invisible tide of nearly half a
million people. Every kilometer of the
1.5 million km journey was paved not
just with rocket fuel, but with the
quiet, relentless expertise of a
civilization working in unison.
Apollo 11 was the ultimate accelerator.
It forced a quantum leap in engineering,
giving birth to the micro electronics
and integrated circuits that power our
modern world. It turned the impossible
into a repeatable industrial process,
creating a blueprint for complex systems
management that we still use to reach
the stars today. But the legacy didn't
stop at the splashdown. It was just
beginning. The nearly 22 kg of rock and
soil the Apollo team brought back
fundamentally rewrote our understanding
of the solar system. By analyzing the
chemistry of the moon, geologists
discovered it wasn't a captured
asteroid, but a piece of the Earth
itself, born from a violent planetary
impact billions of years ago. Even 50
years later, the data still lives on.
Hundreds of scientific papers are
published every year using Apollo era
data as new technology reveals secrets
in the dust that the original scientists
couldn't even imagine. Perhaps more on
that another day. But for now, Apollo 11
wasn't just a journey. It was the
ultimate proof of concept. It showed
that when a species focuses its
collective genius on a single impossible
goal, the quiet expertise of the many
can push the boundaries of human
knowledge forward forever. Hopefully, it
won't be too long until we finally go
back.
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