- [Jared] The year 2019 marks the 50th anniversary
of the Apollo 11 moon landing.
Let's celebrate by using 3D animation
to show the inside of the Apollo Lunar Module.
Let's check it out.
(electricity buzzes)
(explosion pops)
All right, so we're gonna land on the moon.
What should our landing vehicle look like?
Early artwork got their ideas from science fiction.
Then, we started building prototypes.
This one had five legs.
Our astronauts will want to see outside,
so let's make a cockpit with some windows.
(soft music)
The final design has only four legs,
and the windows are much smaller to save weight.
It was about 23-feet tall.
For comparison, here's the size of a person.
The LM was designed and built in Bethpage, New York,
by the Grumman Corporation.
It took hundreds of engineers
and most of the 1960s to complete.
It was originally called
the Lunar Excursion Module, or just LEM.
Eventually, the word excursion was dropped from the acronym,
but everyone still pronounced it the same, LM.
It was a long process to get this machine
all the way to the surface of the moon.
It was launched aboard the Saturn V rocket
and then went to the moon along
with the Service Module and Command Module.
These three parts together are
what we call the Apollo Spacecraft.
The LM was the only part
that goes down to the surface of the moon.
It was the first spacecraft designed
to only operate in the vacuum of space.
So for example, the Command Module needed
to be really aerodynamic for the launch
through the earth's atmosphere.
The LM wasn't exposed until it was in outer space.
Since there's no air up here,
the outline really doesn't matter.
This is part of why you get a spacecraft
that looks unlike anything we've seen before.
Starting with the famous Apollo 11,
there were a total of six moon landings
covering a span of about three years.
Apollo 13 had an accident in space
and was forced to come home early
without landing on the moon.
Earlier missions tested the lunar module in earth orbit,
and then once in lunar orbit
without actually landing on the moon.
More Apollo missions were planned
but were canceled due to budget cuts.
The LM was split up into two parts:
the ascent stage and the descent stage.
For the landing, both parts went to the surface of the moon.
When it's time to leave,
only the ascent stage leaves the surface,
which means that each of the Apollo moon landings
left behind a descent stage.
Let's zoom in for a closer look.
There were four legs attached to the side.
These were originally in the retracted position
so that the limb would fit into the Saturn V for launch.
Then, once they are getting ready to land,
the legs are extended.
Three of the legs contained a contact-sensing probe,
which told the astronauts that they were close enough
to the surface to shut off the descent engine.
This leg has the ladder which the astronauts can climb down.
On the left side of the ladder,
there's a container which holds the American flag.
The shape of the descent stage is somewhat of an octagon.
Here's what the structure looks like underneath.
Inside there were five box-shaped compartments.
The center one contained the decent engine
which was used for landing on the moon.
In order to light this engine up,
we'll need two oxidizer tanks and two fuel tanks.
They both feed right into the engine.
This gives us the propulsion we'll need
to safely land on the moon.
These outer areas are where they stored more equipment.
They called them quadrants.
So this was quadrant one, two, three, and four.
Quadrant one was for general storage.
For the last three Apollo missions,
there was the Lunar Roving Vehicle packed inside of here.
Once on the surface, it was unpacked and ready for use.
This allowed them to explore much further
from the lunar module.
Quadrant two contained a water tank,
and then below here was
the Apollo Lunar Surface Experiments Package, or ALSEP,
which basically contained several science experiments
for them to perform.
Quadrant three had another helium tank, oxygen tank,
and on a few missions it carried retroreflectors,
which is a special kind of mirror.
They were left behind on the surface of the moon,
and they allow scientists even today
to balance laser light from the earth to the moon and back.
Quadrant four contained
the Modularized Equipment Stowage Assembly, or MESA.
And if you've ever wondered how we recorded
those first few steps on the moon,
there's a camera here that points right towards the ladder.
The landing legs were attached on the main structure.
The covering on the outside was made out of Mylar,
which looks like gold tinfoil.
They used it because it was lightweight
and it made sure that the inside temperature didn't get
too hot or too cold.
This the platform that leads to the ladder,
and these are the plume deflectors.
They protected the spacecraft
from the thrusters on the ascent stage.
If we remove the cover,
you can see some of the machinery underneath.
Let's start with the main structure.
This is the crew compartment,
the midsection, and the aft equipment bay.
Both the crew compartment and the midsection
were normally pressurized,
which means that they can safely take off their spacesuits.
The crew compartment didn't have a lot of room.
Controls were mostly in the front,
and then there's two windows
to look outside at the surface of the moon.
The commander was on the left,
and the LM pilot was on the right.
Remember, that the third astronaut
was still orbiting the moon in the CSM.
After landing, this hatch is for the astronauts
to leave the cabin and start their climb down the ladder.
In the midsection, you'll find more equipment
and this cover which protected the ascent engine.
And of course, the tunnel to dock with the Command Module
once back in lunar orbit.
The aft equipment bay has more oxygen and helium tanks
as well as other electronics for the LM.
There's a fuel tank here and a smaller oxidizer tank here.
This is the reason that we have
these bulges on the side here.
Both of these tanks feed right into the ascent engine
which was used to blast off the surface of the moon.
On the outside is the Reaction Control System, or RCS.
It's an arrangement of 16 thrusters in groups of four.
It was powered by fuel and oxidizer tanks on the side here.
During the flight, these thrusters could be used
to maneuver the LM.
The plume deflectors helped redirect
the exhaust to protect the descent stage.
On the outside were several antennas
to let them communicate with Mission Control back on earth.
So much effort went into building each Lunar Module.
What's sad here is that they could only be used once.
Most of the descent stages are peacefully sitting
on the moon, and most of the ascent stages crashed
into the moon after they were discarded in lunar orbit.
A few lunar modules never got the chance to fly in space.
They are now located in museums
along the east coast of the United States.
My name's Jared, and I make 3D animated videos
about how things work.
Click here to learn more about the Apollo Spacecraft,
and click here to subscribe to my channel.
Thanks for watching, and I'll see you next time.