Original subtitles

♪ ♪

NARRATOR: In the 1960s, the dream of a generation comes true.

ARCHIVE: The Eagle has landed!

NARRATOR: Human beings walk on another world...

[Cheering and applause]

...arriving there in an incredible spacecraft.

The Lunar Module.

MARTY: It looks like something that came from outer space.

GERALD: It turned out to be a bug!

NARRATOR: Creating the Lunar Module

is the ultimate engineering challenge.

PAUL: If your Ascent engine doesn’t work you’re dead,

simple as that.

NARRATOR: It takes ingenuity and dogged determination.

MARTY: The technology we had was crude

compared to what exists today.

GERARD: There was always difficulties and problems.

NARRATOR: From risking lives on Earth...

[Explosions]

...to saving lives in space.

ASTRONAUT: Houston, we have a problem.

NARRATOR: This is the story of the unsung heroes

who build the world’s first spacecraft

to land humans on the moon.

NEIL: It’s one small step for man,

one giant leap for mankind.

[♪ theme music ♪]

♪ ♪

NARRATOR: The Lunar Module is an engineering marvel.

The ultimate Winnebago

made from 30 miles of electrical wiring...

half a million rivets...

and ultra-lightweight skin not much thicker than kitchen foil.

It may look like an unconventional flying machine --

but it’s the culmination of millions of man hours

of engineering prowess.

PAUL: It was ugly, but it was beautiful in the fact

that not an ounce was wasted. It’s all form follows function.

NARRATOR: Between 1969 and 1972 the Lunar Modules

carry 12 Americans to the moon’s surface

on six Apollo missions.

They are the spacecraft that make the dream of a generation

come true.

♪ ♪

PRESIDENT KENNEDY: I believe that this nation

should commit itself to achieving the goal,

before this decade is out, of landing a man on the moon

and returning him safely to the Earth.

NARRATOR: May 1961.

Spurred on by the Cold War, President Kennedy delivers

to NASA a seemingly impossible engineering challenge.

To land the first men on the moon.

At the time Glynn Lunney is a young engineer at NASA.

GLYNN: We were thinking that, wow, that is really

an incredible goal to set,

and our minds immediately turned to,

how are we gonna do that?

NARRATOR: It’s all the more incredible

as America’s only spaceflight experience happens

just weeks before the President’s announcement.

GLYNN: We just barely got Al Shepard up,

and he flew a couple hundred miles in the air and came down.

NARRATOR: Astronaut Alan Shepard’s short suborbital hop

lasts just 15 minutes.

Now the goal lies 240,000 miles away.

Kennedy’s dream inspires some of America’s

brightest young engineers.

Like Marty Finkelman.

MARTY: Nobody knew for sure whether we could do it.

NARRATOR: And Stephen Rocamboli.

STEPHEN: Everybody in the world was looking.

What are the Americans doing?

NARRATOR: Before anyone can set to work,

NASA must make a critical choice.

What’s the simplest and most achievable way

of landing on the moon?

PAUL: When the problem of landing on the moon

really became serious and they had to look at it,

the natural assumption is,

look, it’s right there, let’s just go there and land.

♪ ♪

NARRATOR: This no-nonsense approach uses one giant rocket,

in a method dubbed Direct Ascent.

The rocket must be powerful enough

to carry everything needed to reach the moon,

including a big heavy spacecraft over 70 feet tall

that lands on the lunar surface and then lifts off again

to fly back to Earth.

NARRATOR: But as engineers like Gerry Sandler

are quick to point out -- Direct Ascent has a major flaw.

GERRY: Direct Ascent required a great deal of thrust

and a boost larger than anything we could have even imagined

at that time.

NARRATOR: Building a rocket this large and powerful

is likely to make Kennedy’s deadline impossible.

NASA needs an alternative solution.

They explore a riskier method called Earth Orbit Rendezvous.

This requires not one new giant rocket but two smaller rockets,

each launching part of a spacecraft

to be assembled in Earth’s orbit.

But two rockets means double the risk of a failure at launch.

NASA must make a decision quickly.

Enter a young aerospace engineer, John Houbolt.

He’s working on a radical idea.

So radical -- it hasn’t been given the attention it deserves.

PAUL: John Houbolt was the guy who said,

look, you guys aren’t thinking about this properly.

Every time I’ve brought this in front of you

I’ve been dismissed.

NARRATOR: Houbolt rejects Direct Ascent

and Earth Orbit Rendezvous in favor of

a more swiftly achievable method of getting to the moon.

His unpopular idea is called Lunar Orbit Rendezvous, or LOR.

It uses two small spacecraft.

One, called the Lunar Module, descends to the moon’s surface,

while the other, called the Command and Service Module,

remains in lunar orbit.

Once the astronauts have finished on the moon,

the top stage of the Lunar Module returns them

to rendezvous with the Command Module before it’s discarded.

To Houbolt the advantages of LOR are obvious.

PAUL: You need one less launcher,

you don’t need the giant impossible rocket,

and you can dedicate the lunar lander to do the one function,

this difficult thing that we’ve never done before --

landing on the moon.

NARRATOR: But for NASA, LOR has a nightmare scenario.

PAUL: Lunar Orbit Rendezvous was very scary

because if you miss the rendezvous,

if this little ballet of spacecraft trying to join up

doesn’t work, you’re dead.

NARRATOR: But Houbolt isn’t discouraged.

He gambles his career by going straight to the top.

He writes a letter to one of NASA’s senior executives.

JOHN: I fully realize that contacting you in this manner

is somewhat unorthodox.

NARRATOR: Houbolt goes on to lambast his managers

for dismissing LOR.

His conviction’s evident in a copy of his letter.

PAUL: Wow. This is amazing. Yeah, you see this?

"I’ve been appalled at the thinking of individuals

and committees on these matters."

NARRATOR: Houbolt lays it on the line and bluntly asks...

JOHN: Do we want to get to the moon or not?

PAUL: I would say this letter saved NASA from failure

of landing on the moon in time.

NARRATOR: As the clock ticks, NASA engineers finally accept

the LOR method, and on July 11th, 1962,

they announce their decision.

Over a year since Kennedy’s speech, NASA is ready

to choose a contractor to build the Lunar Lander

and reach for the moon.

One company stands out: aircraft manufacturer Grumman.

In November 1962, they win the bid.

But planning the lunar mission has cost precious time.

Grumman engineers will feel the heat,

spending the rest of the decade racing to get to the moon.

♪ ♪

A year and a half since Kennedy’s promise

to land men on the moon, Grumman engineers

must turn their design for the Lunar Lander into a reality.

They have a sterling record in constructing commercial planes

and fighter jets.

But now they face one of the greatest challenges

in aviation history --

engineering a machine that flies not on Earth, but in space.

♪ ♪

The engineers’ initial inspiration comes

from a familiar flying machine on Earth.

PAUL: Their winning design was kind of like a helicopter

with little legs, and the little legs were small,

and they had little pads.

NARRATOR: Grumman’s lunar lander seizes on the design

of the helicopter for one critical reason.

The astronauts must be able to search for a safe place to land.

Almost nothing is known about the lunar surface,

other than it will be unforgiving and treacherous.

A young pioneering rocket scientist, Gerard Elverum,

would be crucial in finding a solution.

GERARD: There were a lot of speculation about

what the surface of the moon was,

whether there was six feet of dust up on the moon

or whether it was a few inches.

NARRATOR: Engineers know it’s going to be dangerous.

They need to predict how the Lunar Module will react on

touchdown and design everything to prevent a crash landing,

which would leave the astronauts stranded on the moon to die.

Engineers must help avert this worst-case scenario.

GERARD: Being able to hover and spend some time

finding where you want to sit down became very important.

♪ ♪

NARRATOR: The astronauts practice in this --

a NASA test vehicle dubbed the Flying Bedstead.

It’s inherently dangerous.

[Explosions]

♪ ♪

Elverum is challenged with designing a way

to allow the astronauts to maneuver

while descending to the moon’s surface.

His solution is to devise a spacecraft engine

that can throttle.

GERARD: It was brand new technology.

So these two valves here control the flow rate

coming from the tanks in the descent stage.

NARRATOR: By controlling the supply of propellant to the

Descent engine, the astronauts can control its thrust,

allowing them to maneuver like a helicopter.

But landing safely on the moon is only half the problem.

The other half is building an engine to get them off the moon.

It would be known as the Ascent engine.

PAUL: The problem with the Ascent engine,

the difficulty was that it had to work every time.

That’s a single point of failure.

If your Ascent engine doesn’t work you’re dead.

Simple as that.

NARRATOR: Like the Descent engine, the Ascent engine

must be as simple and as reliable as possible.

Fresh out of college with a degree in aeronautical

engineering, Tim Harmon is tasked with the challenge.

TIM: We had to keep it simple, and NASA realized that as well.

Not a lot of complexity.

NARRATOR: Keeping it simple means stripping out as many

moving parts as possible -- pumps, valves and turbines.

But the engineers then face another challenge.

If you rip the heart out of a rocket engine,

how do you get it to fire?

The answer lies with the fuel itself.

PAUL: You use propellants that don’t need an igniter,

that don’t need a turbine, a bunch of moving parts,

to suck ’em in and then burn them.

TIM: There are certain combinations of propellants that,

if you mix them, they automatically ignite.

PAUL: One look at each other and they explode on contact.

[Explosion]

NARRATOR: It’s pure simplicity.

Push the two propellants together

in the engine’s combustion chamber, and bang!

But using these self-igniting fuels comes at a cost.

They’re so corrosive that at the end of a test

each engine has to be rebuilt.

It means the final assembly of an engine can never be tested.

DICK: They’d build an engine and they would take it out

to a facility that we had in White Sands, New Mexico,

and they would fire the engine up.

After they fired the engine up,

they would take the entire engine apart and clean it

and reassemble it.

That engine would not be re-fired again

until it was on the mission.

NARRATOR: So when the astronauts use the Ascent engine,

they’ll be gambling with their lives.

These two engines control the two-part Lunar Lander.

The Descent Stage with its throttling engine

flies the astronauts to a soft lunar landing.

And the Ascent Stage launches them safely

back into lunar orbit.

But Grumman’s design is still in its infancy.

As they begin to build, they soon start battling against

every space engineer’s enemy.

Weight.

Like the astronauts, the Lunar Module will be carried

into space by NASA’s mighty Saturn V rocket.

But there’s only so much it can lift.

The problem is, the Lunar Module keeps getting heavier.

DICK: The weight started to climb, and we went 20,000 pounds,

we went 22,000 pounds, 24,000 pounds, err...

It was, it was a constant battle.

NARRATOR: By October 1964 the Lunar Module’s weight

has ballooned to a crippling level.

STEPHEN: Whenever you went to work, even if you made a change, everybody

was saying, well, what’s the implication for weight?

It was there all the time.

DICK: The LEM being overweight late in the program

generated what I would call, uh, a bit of a panic.

NARRATOR: Something has to give.

So Grumman wages all-out war on weight.

Engineers start by shaving off every spare ounce of metal.

DICK: We would be paid $40,000 a pound

for every pound of material that we could scrape off.

NARRATOR: Every part of the Lunar Module’s design

is then re-assessed.

DICK: You wanted to have great visibility,

so they had big windows. Now, glass is very, very heavy.

NARRATOR: The large windows are replaced

with smaller, lighter ones.

But now the seated astronauts can’t see where to land.

GERRY: Somebody came up with the brilliant idea,

why don’t we just put restraints on the crew

and have them stand up facing the window and leaning over,

and get the same angles?

NARRATOR: While descending to the moon, flying sitting down

or standing up makes little difference.

It’s an ingenious weight-saving idea.

Engineers must then find the lightest materials possible

for every part of the Lunar Module.

PAUL: The astronauts lived inside this air balloon

made of metal, and this is the thickness of that balloon.

The astronauts would be on this side, where there was oxygen.

On this side was the deadly vacuum of space.

Twelve-thousandths of an inch thick is all that was.

NARRATOR: In all, the engineers shave off

more than two thousand pounds

and transform the appearance of their Lunar Lander.

Gone are the helicopter-like windows and seats.

Five legs become four.

The circular hatch becomes square.

Heavy panels are replaced with facets of thin aluminum.

By 1967, Grumman has their spacecraft.

But it hasn’t even left the workshop.

When it does, the pressure on the engineers skyrockets.

June 1967, the first Lunar Module, LEM1,

arrives at the Kennedy Space Center in Florida.

It’s already months behind schedule.

And before it can fly, the Lunar Module

must pass NASA’s stringent tests

to see if it can keep two astronauts alive

in the moon’s lethal environment.

STEPHEN: When the LEM goes down to Cape Kennedy,

you know what the first thing they do? They take it apart.

Everything gets taken apart.

NARRATOR: What they find is a disaster

for the Grumman engineers.

The welds on LEM1’s fuel tanks and fuel lines

have a critical problem.

PAUL: They opened it up, they tested it for leaks.

It leaked like a sieve.

They couldn’t believe how badly it leaked.

NARRATOR: The tanks’ welds are riddled with microscopic holes.

Grumman thought their welds were up to standard,

but NASA’s tests are more rigorous.

Unsafe to fly, the Lunar Module is grounded.

DICK: Well, certainly it causes embarrassment,

and to have a setback like that is serious.

NARRATOR: The weld repairs take the engineers 3 months,

delaying LEM1’s flight further.

Meanwhile, back at Grumman in New York,

another crisis throws the schedule into disarray.

It happens toward the end of 1967 during a pressure test.

PAUL: In December, Lunar Module #5, Eagle,

the first one to land on the moon, its window blew out

during a standard test. This was completely unexpected.

[Glass shattering]

STEPHEN: I hear the LEM has had a window failure.

Oh my God, had a window failure?

Right away I said that would cause an astronaut to die.

NARRATOR: The window has a critical flaw

which was missed in the inspection.

But the broken glass also poses a major threat.

STEPHEN: There’s plexiglass and glass all over the interior

of the LEM. There’s, I could see, wires cut, nicked.

NARRATOR: A single shard could short circuit,

the LEM electrics, or worse, severely injure an astronaut

if it’s inhaled.

STEPHEN: I am overwhelmed. I’m going, oh my God,

what are we gonna do? I said, shall we scrap it?

NARRATOR: But Grumman knows that scrapping a

multi-million-dollar spacecraft simply isn’t an option.

Instead they have no choice but to try and save LEM5.

So NASA implements a meticulous clean-up job,

and young engineer Steve Rocamboli is on the front line.

STEPHEN: We could not even see what we were cleaning at times.

There were people with camel hair brushes and filter paper,

and they would go like this and collect particles

on the filter paper that were sent to a quality lab

where our inspectors would count the number of particles

and the size of the particles.

NARRATOR: NASA’s criteria for cleanliness

is agonizingly stringent.

First, every inch of the spacecraft

is photographed in detail.

Then, every fragment of glass collected

from each photographed area is removed from the Lunar Module...

placed under a microscope...

and precisely measured.

STEPHEN: If you had so many particles of a certain size

and density then it would be a problem.

NARRATOR: After a 3-month clean up, NASA finally declares

the Lunar Module is safe for its astronauts.

As Kennedy’s deadline bears down,

the milestones come thick and fast for the engineers.

The millions of hours they have spent on the Lunar Module

begin to pay off.

In March 1969 Grumman’s spacecraft is finally ready

for its first manned test flight.

MISSION CONTROL: The engines are armed;

4, 3, 2, 1, 0... we have liftoff.

NARRATOR: Apollo 9 blasts off with three astronauts on board.

In Earth orbit, the bug-like spacecraft practices

undocking and docking with the Command Module.

APOLLO 9: I have about 370 feet. Okay.

NARRATOR: The test is a complete success.

Two months later, Apollo 10 takes the Lunar Module

even further,

this time descending to within 9 miles of the moon.

ASTRONAUT: Very pretty.

NARRATOR: Now it’s time to head all the way

to the moon’s surface.

♪ ♪

On July 16th, 1969, Apollo 11 thunders skyward

from Cape Kennedy.

MISSION CONTROL: Liftoff. We have a liftoff.

32 minutes past the hour. Liftoff on Apollo 11.

♪ ♪

NARRATOR: Four days later, in lunar orbit, Apollo 11’s crew

powers up the fifth Lunar Module, Eagle,

ready for its descent to the surface.

MISSION CONTROL: Go for undocking.

ASTRONAUT: Roger, Eagle has undocked.

MISSION CONTROL: Roger, how does it look?

ASTRONAUT: The Eagle has wings.

MISSION CONTROL: ...over.

NARRATOR: After seven long years this is the opportunity

for the engineers to beat Kennedy’s deadline.

Now their spacecraft must carry two astronauts

on humanity’s most dangerous journey.

DICK: I was concerned about everything.

The money was on the line now. We were going to the moon.

NARRATOR: Their worries are well-founded.

Eagle’s flight will be far from plain sailing.

July 20th, 1969.

Astronauts Neil Armstrong and Edwin "Buzz" Aldrin

begin man’s first journey to the moon’s surface

aboard their Lunar Module called Eagle.

Now it’s crunch time for the engineers who built it.

MISSION CONTROL: You got a fine-looking flying machine there, Eagle.

NARRATOR: Will Eagle withstand a lunar landing?

MISSION CONTROL: Okay, everybody, let’s hang tight

and look for landing radar.

NARRATOR: The mission hinges on a computer

to guide them down to the lunar surface.

But it has just 1 megahertz of computing speed,

over a thousand times slower than a smartphone.

Such a small amount of processing speed

could prove a showstopper.

NEIL: Program Alarm.

BUZZ: 1202 alarm.

NARRATOR: 1202 is a computer alarm.

Neither astronauts nor most in Mission Control have

a clue how it will interfere with the lunar landing,

including flight director Glynn Lunney.

GLYNN: Oh, yes. I mean, it caused a lot of concern to people

because they all knew that it was a risk to the landing.

They had to decide whether to continue and land

or whether they had to abort.

NARRATOR: They’re within just 40,000 feet of the surface.

But everything the engineers have worked for

hangs in the balance.

One navigation engineer, Jack Garman,

knows what the 1202 alarm means.

He’d seen it before in a simulation landing.

GLYNN: What it amounted to was the computer was issuing

an alarm that says, you are asking me to do too much;

you have overloaded me, the small computer.

NARRATOR: There’s no way of rebooting the computer

to cancel the alarm.

The question is, can the computer keep up

and navigate a landing?

If not they must abort the mission.

ASTRONAUT: Give us a reading on the 1202 program alarm.

PAUL: Jack Garman is looking down at his little cheat sheet,

and he realizes that this alarm problem is one

that cropped up unsuspectedly earlier on

in one of their test training places

and realizes, oh, we can still keep flying

as long as it’s this alarm.

TOM: Jack Garman said, ignore the alarms.

Everything is okay. The vehicle is safe to land.

MISSION CONTROL: We’re go on that flight.

NARRATOR: Jack Garman and the other young engineers

save the astronauts from a last-minute abort.

MISSION CONTROL: You’re go for landing, over.

NARRATOR: Apollo 11 is back on track.

MISSION CONTROL: Go for landing.

NARRATOR: The fragile spacecraft closes in on the lunar surface.

But heart rates in Houston are about to rocket once again.

GERARD: As they looked at where they were supposed to land,

they found that the whole terrain was filled

with boulders and rocks.

NARRATOR: So Armstrong makes a crucial decision.

He accelerates and flies horizontally

to clear the boulder field, using up precious fuel.

MISSION CONTROL: Two fuel only... critical...

NARRATOR: Eagle’s fuel gauge is critically low.

NARRATOR: But incredibly, unbeknownst to both astronauts

and Mission Control, the fuel readings they’re seeing

don’t match what’s actually left in Eagle’s tank.

It all comes down to something called fuel slosh.

PAUL: Fuel slosh was an unexpected problem on the spacecraft.

Because the tanks are round at the bottom

and the spacecraft is moving around,

the propellant is doing this kind of stuff.

And there’s a little indicator at the bottom

that gives ’em an idea of when they’re at low level.

On Apollo 11, because of the slosh,

it was uncovered about almost 40 seconds early.

NARRATOR: The indicators falsely show a low fuel level.

But astronauts and Mission Control are unaware

of the problem, and in a race against time.

PAUL: That’s 40 seconds less time for Armstrong to find

a place to land, which was crucial for him.

MISSION CONTROL: 75 feet...

NARRATOR: Engineer Dick Wilde,

monitoring the life support systems, sees the drama unfold.

DICK: A minute and a half remaining, a minute remaining,

30 seconds remaining, and the guys who were

managing the fuel supply were jumping up and down,

and one of them yelled out, for everybody to hear,

"Land the goddamn thing."

GERARD: And I was sitting back there saying,

"Armstrong, set it down. Set it down. Don’t abort the thing."

ASTRONAUTS: Picking up some dust...

Okay, engines stop! In a descent. We’ve had shutdown.

MISSION CONTROL: We copy you down, Eagle.

Tranquility Base here. The Eagle has landed!

ASTRONAUTS: Roger, Tranquility, we copy you on the ground.

You got a bunch of guys about to turn blue.

We’re breathing again. Thanks a lot!

MISSION CONTROL: Thank you!

DICK: They landed it with seconds of fuel remaining.

That was excitement.

NARRATOR: In reality Armstrong has 40 seconds more fuel

than everyone thinks.

To the engineers it seems the astronauts

have just escaped certain death.

GERARD: The feeling I had when it happened is, it’s done,

never could be undone, you know.

These are the first guys to land on another body from Earth.

And you can’t take that away from me,

and it was my engine that allowed it to happen.

NEIL: It’s one small step for man, one giant leap for mankind.

NARRATOR: A decade-long struggle for the Lunar Module engineers

has finally paid off.

But one engineer is still waiting with bated breath.

Tom Moser designed the US flag for Apollo 11.

TOM: I didn’t think it was a show stopper.

I thought doing something like that was something

that was pretty straightforward.

NARRATOR: Moser has engineered a horizontal pole for the flag

designed to stop it from hanging limp

in the moon’s zero atmosphere.

TOM: The rod had an improper coating on it.

So it wouldn’t extend all the way.

So it looked like the flag was waving in the breeze.

NARRATOR: The flag’s support pole is

a little-known engineering failure.

And leads many to believe the whole mission is a conspiracy

staged here on Earth.

TOM: There’s no atmosphere, there’s no wind up there.

So how could it be waving? It wasn’t waving.

It was just, it was not able to unfurl all the way.

♪ ♪

NARRATOR: The astronauts explore the moon for just a few hours.

Now comes the part that engineers are secretly dreading.

The moment the Lunar Module must help bring them safely home.

MISSION CONTROL: 9... 8... 7...

NARRATOR: If the Ascent engine doesn’t work,

they’ll be stranded on the moon.

MISSION CONTROL: ... 6... 5. Ascent proceed.

PAUL: They just calmly said, "Mission. Beautiful ride."

Everything was fine.

ASTRONAUT: Beautiful... Very smooth, very quiet ride.

PAUL: And that was totally not adequate to express

the engineers’ relief at that moment.

It was really a big deal.

ASTRONAUT: Houston, request manual start override.

DICK: It went flawlessly.

When Apollo 11 lifted off from the moon,

my job was over. Pride was probably the word.

DICK: I went outside and I looked up at the moon and I said,

"I have just witnessed history.

And I have been a part of history,

and I will never look at the moon the same way again."

And to that, to this day that is still true.

NARRATOR: Apollo 11’s resounding success makes history.

The Lunar Module has performed faultlessly.

But its greatest test is yet to come,

during the most epic drama in Apollo’s history.

ASTRONAUT: Houston, we have a problem.

MISSION CONTROL: Stand by, 13. We’re looking at it.

NARRATOR: In April 1970 the Lunar Module

is heading to the moon on Apollo 13.

On board are astronauts Jim Lovell,

Fred Haise and Jack Swigert.

The goal is to explore the Lunar Highlands.

But fifty-six hours in, Apollo 13

suffers a crippling explosion.

[Explosion]

Engineers in Houston, including flight director Glynn Lunney,

face their nightmare scenario.

GLYNN: Somebody turned around to me and said,

"Err, Glynn, you better get out there."

When I get back in all the panels

had warning lights on ’em, and a lot of them were blinking red.

I mean, it was like somebody turned everything upside down.

NARRATOR: The Service Module is losing power and bleeding oxygen.

ASTRONAUTS: We are, we are venting something out into space.

NARRATOR: There is only one option.

To abort the lunar landing

and try to bring the astronauts safely home.

GERRY: We were 200,000 miles already out towards the moon,

so we knew we had to do things that we hadn’t done before,

or even tested before.

We knew we had to use the LEM as a lifeboat.

MISSION CONTROL: I figure we’ve got about 15 minutes’ worth

of power left in the Command Module.

NARRATOR: With the Command Module out of action,

the astronauts retreat

into the attached Lunar Module, Aquarius.

MISSION CONTROL: So we want you to start getting over into

LEM and getting some power on that.

You ready to copy that procedure?

ASTRONAUTS: Okay.

NARRATOR: With its own oxygen and fuel supply,

Aquarius is the crew’s only hope of survival.

But whether the Lunar Module can save them all comes down

to the engineers.

Immediately they face a critical situation.

DICK: We knew that the life support consumables

aboard the Lunar Module were really only designed

to keep 2 astronauts alive for 50 hours.

That defined our problem for us.

NARRATOR: Now the Lunar Module must cope

with three astronauts for eighty hours.

The danger?

The Astronauts are slowly suffocating

on their own exhaled carbon dioxide.

GLYNN: Everybody knew immediately that we had to figure out

something to do about the carbon dioxide,

because we didn’t have enough carbon dioxide scrubbers,

filters, to last us all the way back in the Lunar Module.

NARRATOR: One solution might be to use the CO2 scrubbers from

the Command Module to filter the air in the Lunar Module.

But there’s a potentially deadly problem.

DICK: The kind of failure that occurred had not been forecast.

Their canisters were square, ours were round.

Typical square peg/round hole problem.

NARRATOR: Only the ingenuity of the engineers on Earth

can save the astronauts.

GLYNN: The engineering guys came on and said,

"Glynn, we already have a team of people working on that.

We’ll have an answer for you in several shifts."

NARRATOR: In just a few hours they must do

the seemingly impossible --

engineer an adapter that lets the Command Module’s

square filter operate in the Lunar Module,

replacing the spent cylindrical one.

But they can only use equipment

that’s available to the astronauts.

It is a huge challenge to improvise a low-tech solution

and save the astronauts from asphyxiation.

NARRATOR: The engineers’ design is ingenious.

They use cardboard from reference manuals...

plastic cut from a garment stowage bag...

a spacesuit air hose...

duct tape...

and a sock.

DICK: I said, "Hey, this is gonna work. This is gonna work."

NARRATOR: Swigert, Lovell and Haise

assemble an identical version in space,

with just hours to spare.

MARTY: And all of a sudden they see the level

start to come down. I said, "Wow!"

NARRATOR: The adapter is a triumph.

GLYNN: Very good. We felt exhilarated.

We all loved the Lunar Module.

NARRATOR: Two days later,

when the astronauts splash down in the ocean,

the engineers are elated.

[Cheering and applause]

GERARD: Thank God three guys did not lose their life.

It was nip and tuck all the way, but it worked.

MARTY: I don’t think I had a drink.

I could have used one though.

NARRATOR: The Lunar Module hasn’t only performed

far beyond its design limits.

It has rescued the crew of Apollo 13 from certain death.

♪ ♪

In all, six Lunar Modules land twelve men on the moon.

The last three each transport a Lunar Rover,

allowing the astronauts to travel over 56 miles

of the lunar surface.

In total they spend over 72 hours

exploring this alien world.

In 1972, Harrison Schmitt and Eugene Cernan

are the last two astronauts on the moon.

EUGENE: May the spirit of peace in which we came

be reflected in the lives of all mankind.

♪ ♪

NARRATOR: Humans haven’t returned since then.

But now scientists have the moon in their sights once again.

In 2009, NASA launches an unmanned satellite

called Lunar Reconnaissance Orbiter, or LRO.

Carrying a high-resolution camera, LRO

is revealing the moon in unprecedented detail.

Exploiting resources at the lunar poles

may offer challenges for future generations of engineers,

as lunar scientist Paul Spudis believes.

PAUL: One of the interesting things we found about the poles

is it’s sort of a unique environment.

It has areas that are lit more than half the lunar day.

You can generate electrical power in order to create

sustainable human presence on the moon.

NARRATOR: Engineering giant solar panels would provide

the power needed to build lunar bases.

And mining water frozen in lunar rock

could provide the hydrogen and oxygen fuels

to propel future rockets,

turning the moon into our first off-planet refueling station.

PAUL: So we’re going the next step.

We’re going to sort of the exploration stage.

Think of it as an early mining town.

NARRATOR: While it’s been mapping the moon,

Lunar Reconnaissance Orbiter is also revealing

remnants of Apollo’s legacy...

... lying silently on the moon’s surface.

GERARD: I have six engines sitting on the moon.

I wish I could see them, but I know they’re all up there.

They’ll be there for a million years.

NARRATOR: These are the indelible reminders of a generation

of engineers who dared to explore another world --

and succeeded.

♪ ♪