Original subtitles

MAN: (OVER RADIO) We've got you loud and clear

on the International Space station. Welcome aboard.

NARRATOR: Hurtling around Earth at 17,000mph...

..in the most hostile place humanity has ever attempted to live...

..the International Space Station.

In a space mission, the bad guy is the environment.

The environment is trying to kill you.

Now, 25 years since the first crew arrived on the ISS,

we reveal the times astronauts' lives were in the balance.

We're always asking ourselves, "What's the next worst failure?

"What could go wrong next?"

From toxic leaks...

Do you copy? We're having a hard time with a leak.

Sooner or later, he's got to expose the outside of his suit

to his crewmates, who are not interested in dying horrible deaths.

..to equipment malfunctions...

I don't understand where it's coming from.

There was a risk that if the water increased dramatically,

I would drown in space.

..lethal showers of space junk...

You've got orbital debris

that can hit your module and put a hole in it.

Station to Houston on two. This is an actual.

..to docking disasters.

We are out of attitude by at least 45 degrees and increasing.

..250 miles above Earth.

The smallest mistake could spell disaster.

How do we respond to that unknown?

Understanding situations may have the ultimate consequences.

Split-second decisions mean

the difference between life and death.

From firsthand accounts from ISS astronauts

and Mission Control, who keep them safe...

..this is the untold story of courage,

science,

and survival aboard the ISS.

And we need to be able to handle those things when they happen,

because, in space, it will happen.

Low Earth orbit.

Astronauts Chris Cassidy and Luca Parmitano prepare

the International Space Station for the arrival of a new module.

They have spent years of training,

planning for every possible outcome and every possible failure.

But nothing prepared Luca for this.

250 miles above Earth,

Luca's spacesuit has malfunctioned

and is leaking water into his helmet.

There should never be any water inside your spacesuit,

especially not in the helmet area.

In the microgravity of space,

liquids behave in unexpected ways.

It's surface tension that drives the behaviour of water...

..and the water just wants to stick to whatever it's stuck to.

Chris, you can continue to help troubleshoot...

In Luca's helmet,

the growing ball of water is creeping around his head.

It could smother his nose and mouth.

That's the moment, I think, where it solidified in everybody's mind,

"OK, we're done for today."

In the military, we say that problems happen at the fold

of a map, at the junction of grid squares and at night.

And that's exactly how this was shaping up.

As soon as he started to move, the sun set.

Everything turns gold, bright gold, for one split second.

Incredibly beautiful, and then it's lights out.

Yep.

More water fills Luca's helmet,

causing his communications to malfunction.

I call Chris, telling him, "Hey, Chris, I think I'm a bit lost."

But nothing came out,

and I didn't have any return in my earphones,

so I knew that he couldn't hear me.

Pretty soon, he's not going to have air

in his helmet to breathe.

If the water increased dramatically, I would drown in space.

A routine spacewalk has turned into a life-or-death race

back to the airlock.

The next few moments will not only decide Luca's fate,

but also the future of the space program.

The ISS is the largest and most complex structure

ever built in orbit, a triumph of international cooperation.

But for those who live and work here,

every moment of every day is a calculated risk.

Space is a very hostile, unforgiving environment.

It's an environment that we are not designed to live in.

In space, there's no margin for error.

Radiation,

fire,

contamination,

collision...

..and even drowning are just some of the dangers astronauts face.

So the International Space Station is the place that keeps you alive.

The ISS is the culmination of years of planning,

beginning shortly before the turn of the 21st century...

..a collective effort of more than 50 nations

with unprecedented ambition

to build a state-of-the-art science laboratory in space.

The bold venture kicks off on November 20 1998

from Baikonur Cosmodrome, in Kazakhstan.

A Proton-K rocket carries the Russian component Zarya,

meaning 'sunrise', into orbit.

And lift-off of the space shuttle endeavour.

16 days later, the US Unity module joins Zarya.

(MAN SPEAKS RUSSIAN OVER RADIO)

But it's not until 20 months later, with the arrival of Zvezda,

which means 'star',

that life-support systems and living quarters

are finally added.

On November 2 2000,

the ISS welcomes its first residents.

REPORTER: The first crew of the International Space Station

has reached their home.

NASA astronaut Bill Shepherd and cosmonauts

Yuri Gidzenko and Sergei Krikalev

marking the beginning of continuous habitation

on board the orbiting outpost.

Three spacewalks the following month configure power systems

and add a framework of trusses to support

the station's solar arrays and radiators.

But things are only just getting started.

Great news, Mario, go for docking!

The space station's early success is followed by a sobering truth.

Building a home in orbit is as dangerous as it is ambitious.

And with every new addition, the risks grow.

Its next module, Destiny, an American-built laboratory,

will lay the foundation for US scientific research

aboard the station.

Its installation falls to two first-time spacewalkers -

Top Gun pilot Robert Beamer Curbeam and Tom Jones.

When you're first starting, and you're going out the hatch,

your first thought is, "I want to make sure

"that I get this right, that I do everything right."

While their crewmate Marsha Ivins

uses the shuttle's robotic arm to manoeuvre

the 16-tonne Destiny module into position...

..the spacewalking pair will assist with its attachment to Unity

and integration with the rest of the station.

This is when the game starts,

and you've got to be serious about it.

It's time to go to work.

One of their primary tasks is to connect Destiny's

coolant lines to the space station's cooling system

to regulate the onboard temperature.

Heat doesn't dissipate in space the way it would here.

It just stays there.

And if it just stays there,

you're going to probably overheat whatever you have.

Every 45 minutes,

as the ISS orbits the planet,

its exterior is exposed to direct sunlight,

raising its temperature

to a blistering 250 degrees Fahrenheit.

Then, as the station slips into the Earth's shadow,

the temperature plummets 500 degrees to -250.

To combat these wild temperature extremes,

the space station's cooling system uses loops

of mechanically pumped fluid.

Inside US modules, circulating water transfers heat

to an external loop filled with liquid ammonia...

..which then passes through three waffle-shaped panels

on the station's exterior to radiate the heat into space.

It's this pressurised ammonia loop

that Robert Curbeam needs to connect to Destiny.

The pressurised system keeps the ammonia in liquid form.

Any crystals forming around pipes

or connections are evidence of leaks.

At Johnson Space Centre in Houston,

Lead Flight Director Bob Castle keeps watch over Tom and Beamer.

When he's got the suit on, Bob's completely fine.

But one or two breaths of pure ammonia,

and you will very likely die within minutes.

Everyone watches the systems on the station and on the shuttle

to make sure that everything is still working the way it should be.

While the team knows what's expected of them,

in space, any number of things can go wrong.

When I actually removed the hose,

I saw a lot more crystals growing, all around the two orifices...

..and I knew I had a problem.

An automatic shutoff valve has failed.

I felt like I was working in a blizzard

because there was so much ammonia coming out.

Beamer immediately reported, "Oh, it's spewing all over the place."

And then my counterpart, Andy Algate, said,

"We see the accumulator going down."

Without its coolant,

the Destiny module would be uninhabitable,

potentially jeopardising the entire mission of the space station.

That heat must be ejected from the spacecraft eventually,

or else you will burn up the spacecraft

and the people inside of it.

We don't know exactly what the leak rate was,

but I knew we didn't have long.

Beamer needs to find the shutoff valve upstream and turn it off.

I did find very quickly that it was

going to be a lot harder than I thought.

The valve is stuck.

When I tried to close it, it didn't close.

I tried again, it didn't close.

They said it was going to be about 25lb of force.

I can tell you - I've spent a lot of time in the gym -

it was not 25lb of force.

It was much, much more.

I tried to close it again.

And finally, after four or five tries, I got to close it.

Mission Control breathes a sigh of relief.

With the leak stopped,

the astronauts can connect Destiny's cooling lines to the station.

The ISS is safe.

What's next?

But now Beamer is covered in toxic ammonia.

Sooner or later, he's got to get out of the suit.

And sooner or later, he's got to come back in the cabin

and expose the outside of the suit to his crewmates,

who are not interested in dying horrible deaths.

I thought to myself, "What are they going to do with me,

"you know, now that I have this toxin on the outside of the suit?"

I knew that the procedure to go back into the spacecraft

was going to change.

I just didn't know how.

Tom wipes the toxic crystals off his crewmate's spacesuit,

using a brush in their EVA kit.

But before he can re-enter the space station...

..Beamer must burn the last remaining traces

of ammonia off his suit, in the baking heat of the sun.

The amazing thing about the procedure

to help me decontaminate the outside of my spacesuit was

that it gave me the opportunity

to just sit in the sun and watch the earth go by for 45 minutes...

..which was awesome.

And it was incredible, I loved it.

And you see the Gobi Desert,

you see all the different parts of Asia.

You see the Himalayas to the south.

You see a little bit of cloud layer there.

And you just bask in it.

Over the next four days, undeterred by the experience,

Beamer clocks up 12 more hours of spacewalks

to ensure Destiny is safely attached.

The Destiny module is what we refer to as the US lab.

It's really our core lab capability.

So we have freezers,

we have different payload facilities to conduct science.

This is sort of the heart of the US segment.

Destiny is designed for microgravity research

in a variety of fields,

from life sciences to material science, and more.

Microgravity is not zero gravity.

The Earth still exerts a pull on the ISS.

This pull is what keeps the station in orbit,

circling the Earth in constant freefall...

..creating an environment that allows scientists

to observe phenomena that cannot be replicated on Earth.

But the instruments on board are also designed

to put our own planet under the microscope.

We have a really unique capability to look down on Earth.

Our orbital path takes us around 90% of the Earth's inhabited surfaces.

So this what allows us, over time, to see how the Earth is changing.

How weather patterns are changing and affecting our environment...

..how the forest canopy is changing, and the carbon cycle of Earth.

You have these instruments all

on the same platform, going over the same area.

So you get a global picture

of the health of what's happening to our planet.

The new Destiny module not only provides

a platform for scientific research,

it also increases the habitable

volume of the space station by over 40%...

..a welcome addition

for those building and living on the ISS.

After the installation of the Destiny lab module,

it was fast and furious.

Over the next 21 months, eight successful missions add

the Canadian Space Agency's Canadarm2,

a 57-foot-long robotic arm,

Quest, which will serve as the primary airlock for spacewalks...

..the S0 truss, forming the station's backbone,

and radiator trusses to help dissipate heat.

All of this made possible by an iconic spacecraft.

The ISS could not have been built without the space shuttle.

Full stop.

But in February 2003,

after 16 successful shuttle missions to the space station,

disaster strikes.

Flight controllers, here in Mission Control, have declared

a contingency, as communications was lost

with the Space Shuttle Columbia during its descent

from orbit, enroute to a landing at the Kennedy Space Centre, in Florida.

After more than two weeks conducting experiments in orbit,

Space Shuttle Columbia disintegrates on re-entry,

killing all seven crew members.

Those are my friends, you know? I knew them personally.

I knew them professionally.

Some of them were in my class.

I miss them every day.

It caused us to lose seven very incredible people,

and believe me, they were incredible.

WOMAN: You can just give it to me.

The Columbia disaster, we later found out,

was due to foam shedding off of the external tank.

During launch, a falling piece of insulating foam

struck the shuttle's left wing,

damaging the thermal protection tiles designed

to shield it from extreme heat during re-entry.

And what that did was that allowed very hot plasma

to get inside of the wing and basically melt

the inner structure of the spacecraft.

Test simulations back on the ground reveal the devastating impact

of this seemingly small briefcase-sized chunk of foam

travelling at high speed.

All shuttles are grounded,

while a full investigation is carried out,

effectively halting construction of the ISS.

The only way to reach the orbiting outpost

is via Russian Soyuz capsules launched from Baikonur, Kazakhstan.

To conserve vital supplies, like oxygen and water, on the ISS,

the crew is reduced from three to just two.

Commander Gennady Padalka from Russia

and flight engineer Mike Fincke from the United States formed

the two-person crew of Expedition 9.

I grew up in Pittsburgh, Pennsylvania.

It's not a super wealthy city,

but we have all kinds of resources for education.

So I went to the planetarium, I went to the library,

I learned, and I knew that I wanted to become an astronaut.

I met my wife at Johnson Space Centre, here at NASA.

And like men and women do, we fell in love and we started a family.

And I still hadn't flown yet.

And then the opportunity came up.

When I married him, I knew that he wanted to go into space.

And so, I was always going to support his dream,

even though it was going to disrupt our planning for life on the ground.

Mike spent eight years training before this mission...

..a mission scheduled to last six months.

It's been his ultimate ambition,

but one that involves personal sacrifice

for himself and his wife, Renita.

It was about two months into his six-month mission

that we had the baby.

For the first time in history,

an American astronaut is in space when his child is born.

It will be four months before Mike returns

to Earth to hold his daughter for the first time.

During his absence, she will grow.

But Mike's body will also undergo changes.

While his new baby is developing muscles quickly,

Mike's muscles will deteriorate because of microgravity.

Renita and fellow biomedical engineers

at Johnson Space Centre research ways to overcome this challenge.

As you're up there longer and using your muscles less,

you're going to need to find ways

to counteract all the changes that are happening.

Without exercise,

astronauts' muscle mass can fall by up to 50% over a six-month mission.

We provide crew members with aerobic exercise,

as well as resistance exercise,

so we're able to build muscle

as we're exercising,

so that we can make sure that everybody is fit

for doing what their duties are in space.

In their role as the station's caretakers,

the crew must occasionally carry out physically

exhausting work on the outside of the space station.

For Mike and Gennady,

this poses an additional challenge,

since, for safety,

spacewalks require two crew members.

This means leaving the ISS

completely unoccupied during the operation.

One of our planned spacewalks was to travel to the very end

of the space station, which is the very aft end of Zvezda.

The plan is to install equipment in preparation

for the arrival of a cargo vehicle from the European Space Agency.

The two spacewalkers undertake a tightly choreographed procedure,

But no matter how much they plan and practise, in space,

there's always room for the unexpected.

We're always asking ourselves, "What's the next worst failure?

"What could go wrong next?"

We need to be able to handle those kind of things

when they happen because, in space, it will happen.

Two hours into the spacewalk, it does.

Gennady and I were just working away,

doing what we needed to do.

But as they worked,

they were inadvertently causing a problem.

Our spacesuits were providing a very little bit

of momentum towards pushing the space station.

So we were actually pushing it to go out of orientation.

The two astronauts working at one end of the station

have caused the entire structure to tip.

How could this happen?

The stability of the ISS and its orientation,

or 'attitude', should be maintained through the use of four Gyroscopes.

A gyroscope is a wheel or disc spinning on its axis.

The heavier the disc, and the faster it spins,

the more stable the gyroscope.

That's because a spinning disc creates momentum perpendicular

to the plane of rotation, which makes it resist tipping over.

Embedded in the ISS

are four huge gyroscopes, pointed in different directions,

with 220lb wheels spinning at over 100 revolutions a second...

..usually enough to keep the whole station

from rotating in any direction.

The space station constantly experiences forces

from solar winds or from the Earth's gravity.

If left unchecked, they would cause the space station to tilt or tumble.

The gyros counteract those movements.

But they can only compensate so much.

And they're already close to their limit

when Mike and Gennady push the station out of alignment.

So the space station went into a mode that said, "Look,

"I can't control myself anymore.

"I'm not out of control,

"but I'm going to go into what we call 'free drift'."

So the space station just started to drift and point up and point up.

And there we are.

And we looked up, and we were in a very unusual attitude.

And there was... Planet Earth was zooming below.

Holding a desired orientation in space is crucial to help keep

the station's solar arrays locked onto the sun.

This isn't just about efficiency - it's about survival.

We're completely off the grid.

And in order to keep it powered,

we're collecting as much solar energy as we can when we're on

the light side of the planet.

When the station slips into darkness for 45 minutes every orbit,

solar-charged batteries become crucial

for powering critical life-support systems.

With the solar panels unable

to charge the ISS's batteries,

to conserve power, Mission Control turns off nonessential systems.

The only way to get the space station back

into the correct attitude

is with the use of thrusters,

located exactly where Mike and Gennady are working.

But there's a new problem.

Gennady and I were working and talking

to our Russian colleagues on the ground,

and all of a sudden, it became very quiet.

The power-saving protocols have inadvertently cut off

all communication between the astronauts and ground control.

There was no-one else to give us instructions.

And Gennady and I said, "Well, what are we going to do?"

Mission Control has a terrible dilemma.

To restore attitude, they must activate the thrusters.

But with no way to communicate with Gennady and Mike,

flight controllers have no idea

whether their astronauts are in the firing line.

If a crew member was going to be moving by them,

that crew member would be blasted with hot gas

or contaminated because the gas

that the thrusters used was extremely toxic.

Extremely, extremely toxic. Deadly.

We don't want to be anywhere near that action.

If we were there in our spacesuits when the thrusters went off,

we would experience the thrill of being melted.

Suspended hundreds of miles above Earth,

the two spacewalkers cling to an empty,

drifting space station, unsure what to do next.

As the planet turns slowly beneath them,

Mike scans the horizon...

..and spots something that provides a spark of hope against the void.

We saw where we were going.

We were headed over Greece and headed north and east,

so we knew we were going to be over what we call 'Russian ground site'.

After several minutes of silence...

(MAN SPEAKS RUSSIAN OVER RADIO)

..success.

Roscosmos manages to re-establish backup communications.

We heard Moscow. They said,

"Hey, guys, you know the space station

"is not in good control.

"We need to re-establish control.

"We highly suggest... In fact, we tell you to move away

"from those thrusters.

"It's not in your interest to stay there."

So we had to go hand over hand to move away from the thrusters,

to be safe from any plume damage or any heat that was being produced.

With the pair clear, the thrusters are fired.

Attitude re-established.

It was a good view.

We got to look at planet Earth as we regained orientation

from being pitched up all the way, being pitched down.

We got the chance to just sit there

and wait as the station regained its orientation.

Then they said, "OK, we're back to normal work.

"Get back out there and finish your job. Stop slacking."

On October 23 2004,

after travelling more

than 78 million miles aboard the International Space Station,

Expedition 9 hands over command of the outpost to the crew

of Expedition 10

and makes preparations to return to Earth.

By the end of the mission, I was kind of missing things

back on planet Earth.

I was missing my family - it got bigger while I was gone.

We had a baby, and I knew I had to go back home.

For almost two years, ISS has been in stasis,

with no way of getting new modules up,

its completion relies on one crucial factor -

NASA's return to flight.

Less than a year after Mike's return to Earth,

following an overhaul of NASA's safety practices,

the space shuttle program is reinstated,

with the first assignment a mission to the ISS.

On July 26 2005,

the crew of Discovery prepares for STS-114.

STS-114 was our return to flight after the Columbia tragedy.

We had made mistakes, and we were ready to fly again,

with the solutions to be able to show

that we belonged in space and we could keep going.

OK, here we go.

The fact is, we had to have the space shuttle

to finish building the International Space Station.

For mission specialist Wendy Lawrence,

STS-114 will be her first visit to the ISS

and fourth and final venture into space.

The flight will carry supplies to the station and prove

that the shuttle program is safe enough to continue.

MAN: (OVER RADIO) I've got you loud and clear as well. Ready to go.

Seven. Six. Five.

Three engines up and burning. Three.

Main engines lit off. Solid rocket boosters lit off.

You literally feel like you're in your slingshot.

You know when you're leaving the launch pad.

In the wake of the Columbia disaster,

NASA implements a series of new safety protocols -

a redesign of the shuttle's external tank to reduce

the potential for foam shedding...

..installation of multiple cameras

to cover the launch and check for any anomalies...

..and an enhanced in-orbit inspection

of the shuttle, using new cameras and sensors.

Discovery reaches orbit, apparently without issue.

Flight day two for us was the initial on-orbit inspection.

We used the shuttle robotic arm and the new sensor package

to examine the structural integrity of the thermal protection system,

to see if there was any damage that may have occurred.

Meanwhile, on the ground, analysts scour footage of the launch...

..and discover several troubling incidents.

A large bird hitting the shuttle's fuel tank.

A small piece of thermal tile detaching.

And a large section of foam falling from the external tank.

Could history be repeating itself?

We looked at the side of the vehicle.

We looked around our nose cap area, as well.

Didn't see any damage, so we were like,

"OK, not great to hear that foam came off.

"Doesn't look like it hit a critical area."

The inspection isn't conclusive, though.

They need a closer look.

And to do that,

they'll need the help of the ISS crew

and a shuttle manoeuvre never before attempted.

We came to 600ft below the station.

We basically did a backflip.

Inside Discovery, Commander Eileen Collins initiates

the manoeuvre to pitch the shuttle 360 degrees.

The shuttle was performing what we called

the 'rendezvous pitch manoeuvre',

to allow the ISS crew to take scores of high-resolution photographs.

The crew on board the ISS have a window of just 93 seconds

when the underside is in the sun,

to take high-resolution images of the shuttle's heat shield.

Those were then downlinked to engineers

to be able to look for any damage or misconfiguration of those tiles.

As we came out of our backflip, we got to watch Space Station

come up over the tail of our orbiter, Discovery.

And I called that our Star Wars moment.

This was just so cool. It was like, "Here's this big spacecraft,

"right next to mine, rising up over the tail."

While the shuttle crew unload supplies onto the station,

engineers on the ground pore over the images of the shuttle,

searching for anything out of the ordinary.

Engineers identified that there was a small piece of gap-filler.

What this is is a piece of fabric

that is meant to fill spaces in between the tiles on the orbiter.

This gap filler had actually stuck up into the surrounding area

above the outer mould line of the orbiter.

So there were two of these gap-fillers sticking out

from in between the tiles, on the underside of Discovery,

something I'd never seen before.

The problem with this is,

as this re-enters the Earth's atmosphere,

this could actually cause the smooth flow to hit

that gap-filler and then become turbulent,

which creates downstream heating

and puts extra heat stress on the orbiter tiles.

The flow might come back together in a way,

where it now becomes almost like a blowtorch,

and it might burn through one of the thermal-protection-system tiles.

This could turn the shuttle into a fireball.

The gap-fillers protect the tiles

from vibrations on launch, but are not needed for re-entry.

The decision was made that these two gap-fillers

really need to be removed before we'd come back for landing.

MAN: (OVER RADIO) One hour and ten minutes. The IMU aligned.

The underside of the Space Shuttle orbiter was not designed

to have astronauts there - there were no handholds whatsoever.

Really, the only way for us to have done

the gap-filler removal was to have

a crew member on the end of a robotic arm.

(MAN SPEAKS INDISTINCTLY OVER RADIO)

I got to fly the station robotic arm for that EVA.

Steve Robinson was on the end of the arm,

and I flew him to where no astronaut had ever been before,

on the underside of the Space Shuttle orbiter, beneath the belly.

Once Steve locates the gap-fillers, he must remove them.

After a two-week, 5.8 million-mile journey in space,

on August 9 2005, Discovery sets off for home.

WOMAN: (OVER RADIO) See circuit breakers coming back in?

MAN: (OVER RADIO) OK, we did see that.

Only now will the team find out if the fix worked.

Discovery's altitude now, 72 miles. Speed, 17,000mph.

And now, all of a sudden, you're coming back to gravity,

something you've spent virtually your entire life in.

And it's not pleasant.

The shuttle's immense speed, as it re-enters Earth's

atmosphere, superheats the air,

tearing molecules apart, creating a plasma.

Temperatures outside soar

to a blistering 3,000 degrees Fahrenheit.

As Discovery descends into the atmosphere,

it will perform a series of four banks to dissipate speed.

Well past the point of no return,

all the seven crew members can do now is trust

that their inspection was thorough and the repair is sufficient.

Main gear. Touch down.

Nose gear. Touch down.

And Discovery is home.

Let me tell you, when Discovery touched down on the runway,

we knew that it had been a flawless re-entry profile.

There was a sense of both relief and accomplishment of all the teams

that had shown that we could again fly the space shuttle safely.

With the shuttle program reinstated,

construction of the ISS can now resume.

Over the next six years,

19 shuttle missions and 94 spacewalks.

Numerous parts and modules are bolted on

to the International Space Station.

Among them, Columbus,

a cutting-edge science laboratory from Europe...

..the Japanese Kibo laboratory...

..with an exterior facility to conduct Earth observation,

communication, and material science research...

..the Poisk Mini-Research Module 2,

Russia's first major addition since 2001,

and the Tranquillity module,

with its now world-famous observation cupola.

In May 2011, the ISS is finally complete -

a $150 billion space laboratory.

When we humans really want to...

..we can take that proverbial sword

and we can truly beat it into a ploughshare.

We can do some pretty remarkable things together,

peacefully, for the benefit of all humankind.

We've opened some of the secrets of the universe,

all the way from science and physics to how to work together as humans,

how to...how to plan and overcome difficulties together.

It was a milestone many, many,

many people had been working to to achieve its original goal,

which to be a place where you could do scientific research

in a very unique environment, that of microgravity.

But what makes it unique also makes it perilous.

In space, you are constantly at risk of dying for a multitude of reasons.

Survival in space is on a knife's edge.

Very quickly, you can have an out-of-control situation

from a very innocuous start.

I have a lot of water.

Over the next 15 years,

events on the ISS will test the powers of human ingenuity

to its limits,

to keep astronauts alive and prevent the space station from breaking up.

This was like riding a bucking bronco,

and we've got to make it the full eight seconds,

except this time it was in orbit around the entire Earth.