All language subtitles for How.The.Universe.Works.S08E02.NASAs.Journey.To.Mars.1080p.AMZN.WEB-DL.DDP2.0.H.264-alfaHD_track4_[eng]

NARRATOR: 'NASA has set its sights
on Mars.

Its goal is to send humans
to the red planet

in the next 20 years.'

Looking up at Mars in the sky,
I really do feel like
I'm looking at a place

that, someday, there will be
people walking around on it.

It feels so much like Earth
in so many ways

and it's a place
that really captures

my imagination as a result.

It's the most Earth-like environment
we see in our solar system.

So, we're not gonna leave it alone.
We're gonna try to do this.

'But conquering
our planetary neighbour

is a tougher challenge
than we ever thought possible.'

It's an isolated environment

where a million things can go wrong,

where there's absolutely
no hope of rescue.

There are
so many hurdles to overcome
for human exploration of Mars

and it makes it quite difficult.

Sure, we can get there,
but are we gonna be in one piece?

Sometimes it feels like Mars
is designed to keep us away.

'Are we doomed to fail
in this endeavour?'

'The red planet, Earth's neighbour...

..and the destination of NASA's
most ambitious mission to date.

But this expedition will be harder
than we ever thought possible.

It hurts to think of how hard it is.

It's the farthest a human being
has ever been from the Earth.

We gotta take every precaution.

'As NASA astronauts arrive at Mars,

they will face a huge obstacle.

Landing on the planet
is a daunting task.

In the past Mars hasn't always
rolled out the welcome mat.'

Mars is kind of like
a graveyard for spacecraft.

It's actually really hard
to send something

from Earth and land it on Mars.

'This is how
the European Space Agency

hoped its $250 million
Schiaparelli lander

would touch down in 2016.

But the lander's systems
got it wrong.

The parachute detached early,

sending the craft into free fall
for 33 seconds.

Schiaparelli smashed into the surface

at 335 miles per hour...

..leaving a deep black scar
in the Martian landscape.'

It turns out that Mars
is actually a particularly
difficult planet to land on.

Even humanity's
most brilliant engineers,

we've got about a 50% success rate

when it comes to landing on Mars.

'The red planet is littered
with dead spacecraft

that didn't nail the landing.

And, for NASA's first crew descent
to Mars,

the space agency must learn
from these mistakes.

But as the crew hurdles
towards the surface,

they're battling the same problem
as all the landers

that failed before.

The Martian atmosphere
is 100 times thinner than Earth's,

so it can't provide the drag needed
to slow a spacecraft down.'

It's not like the Earth where you
can have these big giant parachutes

that gently glide you
down to the surface.

You can use some of the air,
but it's hard.

'The red planet's thin atmosphere
is a problem

that has been billions
of years in the making.'

Mars doesn't have a large atmosphere
because it's constantly being

peeled away due to the lack
of protection of a magnetic field.

'The solar wind can strip away
an atmosphere.

On Earth, a liquid metal core
creates a magnetic field

which shields the planet
and helps maintain the atmosphere.

But Mars is different.

4.5 billion years ago,

Mars and Earth formed
from dust and gas in space.

Mars formed, where building materials
were scarce.

Its growth was stunted.'

So, Mars is much smaller
than the Earth.

It's a factor of ten
smaller than the Earth.

And that factor of ten,
in mass, is important.

All of that extra mass allows
the inside of the Earth to stay warm

and to have a core that's rotating
which generates a magnetic field.

'Four billion years ago,
the churning heart of Mars

started to cool and solidify.'

With no hot core, there's no
magnetic field being generated.

All of the high-velocity charge
particles coming from the sun

pick away at the atmosphere
and slowly tear it away.

We know it's losing atmosphere
every second due to the solar wind,

so, you know, bye-bye, atmosphere.

With little Martian atmosphere
to work with,

NASA had to be creative
to get its crewless landers

to the Martian surface.

In 2012, the revolutionary sky crane

landed the Curiosity rover,

using parachutes and retro rockets.'

Previous missions have used
both a parachute and something else,

like a bouncy ball
inflated around the spacecraft.

I don't think a human crew
is gonna be too pleased

if they're gonna be bouncing
onto the surface in an airbag,
rolling to a stop.

'To land people on Mars,

NASA needs some new tricks.

The 2020 rover
will overcome the challenge...

..with the Advanced Supersonic

Parachute Inflation
Research Experiment -

ASPIRE.

It will rapidly
slow down the craft...

..with the force
of an airplane jet engine.'

This is fine for the rover,
it's actually gonna work no problem,

but it's not gonna work for people.

'A human lander will weigh far more

than the 2300-pound rover.

Not even supersonic parachutes

could land a crew safely on Mars.

NASA will need a new plan.

One idea is to use
the thin Martian atmosphere

in a unique way.'

There's an idea
of coming in really fast,

getting to the thick part
of the atmosphere

and then, going horizontal
to the ground and gliding

and losing your momentum that way.

'As the astronauts descend,

they'd tilt the nose of the lander
towards the Martian surface,

aiming for the thickest part of
the atmosphere close to the ground.

Then they'd pull up
at the last second,

using friction from the atmosphere
to slow the craft.

Descent engines switch on
for the final touchdown.'

JANI: Is this a crazy idea? I mean,
yeah, it's a little bit weird.

I don't know if we'd really think
about doing something like this,

but you've gotta think
outside the box sometimes.

'Right now, NASA's plan
for landing a craft on Mars

are still on the drawing board.

But even if they can get astronauts
onto the surface,

the thin atmosphere
isn't done with them yet.

It causes swirling dust storms

that cover the planet's
entire surface.'

Mars doesn't just have dust devils,
it has dust hell.

'And these towering clouds
have killed before.'

'If NASA's astronauts arrive on Mars

as planned, in 2035,

the settlers will find
one of the red planet's
biggest challenges...

..is its dust.'

It's sticky.

Basically, light from the sun
can give this stuff a static charge

and then it clings to stuff.

So, it's not just a matter of, like,
you know, standing on a doormat

outside your space habitat
and shaking yourself off.

It's gonna get in your spacesuit,
it's gonna coat your visor,
it's gonna cover your solar panels.

PHIL: If you get it in your lungs,
it's not a good thing.

We have to figure out
how to clear this stuff out.

MAN OVER RADIO: 300 feet minus 11.'

'Through the '60s and '70s...'

'There you go.'

'..Apollo astronauts
walked on the moon.

When they returned
to their landing module,

they brought moon dust
back with them.

The lunar dust clogged seals,

caused equipment to overheat,

resulted in false instrument readings

and even made astronauts sick.'

You don't wanna be breathing in
fine, dusty material.

By itself, you can get things
like silicosis.

It's, you know, almost basically
a lung cancer that you can get

just from breathing in the dust
itself. You don't wanna do that.

'The red planet is covered
in sticky dust...

..and new research suggests
it all came from one place.

The Medusa Fossae Formation.

When the 600-mile-long
volcanic deposit formed

three billion years ago,

it was around half the size
of the United States.

But the Martian winds
have eroded this structure

and spread the dust across
the entire planet.

When the wind whips up this dust,

it can have disastrous consequences.'

The real problem is
just that all these fine particles

get lofted into the atmosphere

and it takes a really long time
for them to settle back out.

And what the dust does
is it just gets up in the sky

and it sits there and sits there
and sits there.

'As more material gets lifted
into the atmosphere,

it forms huge dust storms.

The storms are so huge
they block out the sunlight

and cool the Martian surface...

..creating a temperature difference
between the ground and atmosphere

that causes winds to increase

and the storms to grow.

And NASA's Opportunity rover
knows first hand

the dangers of being trapped in one.'

Opportunity was a NASA rover
sent to Mars

to hunt for signs of past water
on the surface

and, potentially,
signs of past life.

This is a rover that we
really worked with so long,

knew so well and who had come up
with so many amazing

new results from Mars.

'June 2018.

Opportunity was 15 years
into its mission.

When giant clouds of dust
appeared on the horizon,

NASA could only watch
as the storm grew and grew.'

Once this dust storm
coated the entire planet,

it blocked the sun,

and the sun was the source
of Opportunity's power.

Opportunity works using solar panels

and so it gradually got less
and less and less electricity.

'For Opportunity there was no escape.

Lost in the darkness,

Opportunity's power reserves
slowly ran dry.

The rover fell silent.'

We thought, "Maybe,
once the dust storm clears up,

the panels can fire up again
and we can get it back,

but it just never woke up.

'If NASA astronauts
do make it to Mars,

the storms could damage more
than the crew's power supply.'

(LIGHTNING CRACKING)

'When the storms begin to blow,

they crackle with electricity.'

Just like you can create
a static charge by rubbing
your foot on the carpet,

or a balloon on your hair,

this happens at large scale
in these dust storms on Mars.

The sand grains
rub up against each other

and that creates the static charge.

So you get these electrical flows
that occur.

DAN: Here on Earth,
we see this in volcanic eruptions

as the dust, the ash, burbling out
of one of these huge eruptions.

You'll see lightening discharges

in those volcanic plumes
from the same charge transfer.

If you're at a place with
a lot of electrostatic discharge,

that means sparks are gonna fly,
which is really terrible
for operating instruments.

'To survive on Mars,
the settlers are going to need

a protective shelter.'

The key word to living on Mars
is "protection".

Protection from the cold,

protection from the lack
of atmosphere, protection from
the radiation from space.

'NASA could build shelters,

but Martian history
offers them a shortcut.

Millions of years ago,

the planet's volcanoes
erupted huge amounts of lava.'

But the silver lining is
that as the lava was flowing away,

it did that through
underground tubes.

And then, as the lava evacuated
away, it left behind empty caverns,

just like this big lava tube
that we're standing in right now.

'Martian gravity is a third
as strong as Earth's,

thanks to the red planet's
lower mass.

So, when Martian lava
flows underground,

it meets less resistance

and can carve out
monstrous cave systems -

natural astronaut shelters,

hidden away from the red planet's
dust storms.'

If you actually then seal them,

you can fill them with air and
you've got a great place to live.

These tunnels are ready made
for people to move into.

We already have the keys.

'But a lava tube may not be
everyone's idea of home sweet home.'

Because they're a natural feature,

you can't pick and choose
where they are, you have to go to
where they already exist.

'Building their own shelters

gives the astronauts more options
where they can live.

And they can be built by robots

before the settlers arrive.'

- PHIL: We could even send3 -D printers.

I'm talking about something
that actually uses the rock there

and makes something like concrete

and it could build structures
for us to live in.

'NASA challenged the tech industry

to develop Martian shelters

built by autonomous robots.'

It sounds like something out of
a wonderful science fiction story,
but we already have this technology,

We, on Earth,
- can actually 3
- D print houses already
by actually just adding concrete.

So, we have all of the technology
necessary to do this.

Now it's just,
"Do we have the will?"

'In May of 2019,
NASA announced the winning team.

AI Space Factory built a structure
that withstood rigorous pressure

and impact testing.

- It can be 3
- D-printed in 30 hours

and made from materials
found on Mars.

Once scaled up, the habitat
could protect settlers

from the inhospitable conditions
on the red planet.

Even with shelters,
the settlers will need to eat,

breathe and drink.

But there is no food, breathable
oxygen or liquid water on Mars.'

So, even though Mars is the closest
friendly environment

to life that there is to the Earth,
it's really not all that friendly.

'Without easy access
to the essentials of life,

will settling on Mars be possible?'

'Compared to Earth, life on Mars
is a recipe for disaster.'

If you look at it as a human being
who wants to live there,

yeah, this an alien world that's
gonna try to kill you at every step.

It's far away, it's cold.

There are just so many reasons
why we wouldn't be
happy campers on Mars.

So, why on earth are we talking
about sending people there?

Well, the next closest planet,
Venus, it's way worse.

Its surface is super-hot.

It's got horrible chemicals
in the atmosphere.

So, in comparison, Mars looks like
a great, great place to visit.

It's close,
it's relatively Earth-like

and although there are
many challenges,

they're challenges
that we could overcome.

'To settle on Mars, NASA's astronauts
need a few essentials.'

If we want to live there -
short term or long term -

you know, what do you need,
physically? Well, you need air,

you need water, you need food.

Those are all things
that we can bring with us,

but it's a lot easier
if they exist there on Mars.

'The settlers will need
to grow their own food,

but the Martian ground is poisonous.'

Mars's dust looks really benign.

It looks like dust you would find
in southern Utah,

but it turns out it contains a lot
of something called perchlorates

and these materials
are really toxic to human life.

'Perchlorates are chemicals
formed by electricity
produced in Martian dust storms...

..and they make up around 1%
of the Martian soil.'

Which doesn't sound like much,

but this could be
a significant problem

for any humans living on the surface
of the red planet.

'Food grown in the Martian dirt
will absorb the perchlorates,

posing a health hazard
for the astronauts.

But that's not all.

Direct exposure to the toxic soil

will make astronauts very sick.'

One of the effects that perchlorates
have, biologically, in our bodies,

is to, sort of, mess with and alter
the function of our thyroid glands.

'Astronauts would get rashes,
feel nauseous.

Extended exposure to the dirt
could even kill them.'

And Mars is not the sort of place
where you would ever

want to get seriously ill,
millions of miles

from all the hospitals
and health care of the Earth.

'There are ideas of how to clean
the poisonous soil,

using water or bacteria,
but the technology is not ready.

The first settlers will need to find
a safer way to grow food

and NASA has the solution.

Hydroponics will provide all the food
a Martian settler might need.

Instead of growing in soil,

the settlers will grow crops
in water.

So, all you need to do
is bring the seeds,

or the plants, and then have them
grow right there in water.

But if we decide to grow
our crops hydroponically on Mars,

we still have this problem
of needing lots and lots of water.

'But before astronauts
water their plants,

they'll need water to drink -

and Mars hasn't had running water
for millions of years.'

We've all seen the movies of people
stranded in different places

and having to survive and they can
last for months without food,

but a human cannot last beyond
three days without water.

'Astronauts on the International
Space Station

recycle water from bathing,
breath, urine and sweat,

but they still need 1500 gallons
sent up each year.

Each delivery weighs over six tons.

Transporting water to Mars

will add a lot of weight
to the manifest.'

You have to use fuel to launch it,

but then you also have to use
more fuel to launch the weight

of the other fuel,
and so on and so on.

You have to keep
to an absolute minimum

the amount of weight
you try to launch from Earth.

'So, if NASA wants to set up
residence on Mars,

astronauts will need to find
a water source.

Even though no liquid water exists
on the planet's surface,

there are other places to look.'

It turns out there is
a lot of water on Mars.

It's trapped underneath the ground,
beneath the dirt and the soils
at high latitudes.

It's also found in huge volumes
up at the polar ice caps.

Ice, you melt and it becomes water,
you can drink it. Yay.

You can grow plants
and do things like that.

In fact, if you were to melt
all of Mars's polar ice,

then you would be able to cover
the globe in water.

So, ice is an extremely important
thing to have access to.

So, if we do go to Mars
to explore and live there,

following the ice
is the way it's gonna go.

'Even if NASA astronauts can turn the
Martian ice into drinking water...

..without another resource,

settlers will be dead
in three minutes.

That resource is oxygen.'

There is oxygen on Mars,
but it's not in the air.
You can't breathe it.

It's bound up in the dirt

and combined with iron
to make iron oxide,

giving it
its characteristic red colour.

And so we need to bring it with us,
and that's a huge amount to bring,

or, we need to make it at Mars
and that's really difficult.

'We can deliver oxygen to the ISS...

..but the trip to Mars is long,

so, there will be
few supply missions.'

Once you're on Mars,
you can't pull out your app

and order an oxygen delivery
to your door.

You gotta take it with you,
and that's a lot of oxygen.

'NASA astronauts will need a way
to make oxygen on the red planet

and the space agency
is working on a solution.

When their 2020 rover
arrives on Mars,

it will carry out Mars Oxygen In-Situ
Resource Utilization Experiment -

or MOXIE.'

MOXIE will take carbon dioxide
from the Martian air

and use electricity to split
that CO2 and release oxygen

that astronauts could breathe
in the future.

'This test will create oxygen
on another planet

for the first time,

but MOXIE can't make enough
for a crewed mission to Mars.'

MOXIE will be able to make about
half a pound of oxygen per day,

which is only enough to keep
a human alive for about six hours.

'NASA needs to significantly
scale up the technology

to support a whole crew on Mars.

But even if the astronauts
can survive on the red planet...

..can they actually reach it?'

This is a long trip in a bathtub
with three other people.

It's challenging,
I think we're still
asking ourselves this question,

"How will we do it?"

'NASA's solution is Orion,

a 28-ton spacecraft,

nearly twice the mass
of a school bus.

The rocket that launches Orion

will need to produce
millions of pounds of thrust...

..and that's a problem.'

If we decided tomorrow like,
"Hey, you know, what,

let's go to Mars," we can't.

We don't have powerful enough
rockets to do it.

'In 1969, NASA's Saturn V rocket

fired Apollo astronauts to the moon

with 7.6 million pounds of thrust.

That's the power
of more than 34 Jumbo jets.

A Saturn V could have sent
astronauts to Mars.'

Not any more. We stopped making 'em.

'To break free from Earth's gravity,

the space rocket must travel
at 25,000 miles an hour.

To achieve that, NASA is building

the most powerful rocket
in the world.

The Space Launch System, or SLS,
is the rocket that's being designed

to carry Orion off of Earth
and beyond lower Earth orbit.

And the philosophy is,
"Hey, remember those big rockets

that we used to make
back in the '60s and stuff?

Let's do that again, but more so."

It's really big.
It's larger than the Saturn V rocket

that was built to carry
the Apollo spacecraft

and, is therefore, gonna be
the largest rocket built.

'The Space Launch System

will be taller than
the Statue Of Liberty.

Its gargantuan engines
will thrust the rocket

through the atmosphere with
the horsepower of 160,000 Corvettes,

producing 8.8 million pounds
of thrust.

The SLS will be able to blast
the Orion capsule into space

and send it on its way to Mars.

Unfortunately, the rocket
has fallen behind schedule.

Its maiden test flight was set
for December 2017.

Now it's scheduled
for the end of 2020.

Critics see the SLS
as a waste of money,

with the project reported to be
billions of dollars over budget.'

The key to doing any of this
is to have the access to space
be affordable.

If it's out of the question
to spend the money to do it,

we're never gonna be able to do it.

'And with SpaceX developing
reusable rockets,

NASA's single-use SLS

is beginning to look
even less appealing.'

The reason air travel is inexpensive
is because we figured out

how to use planes
over and over again, basically.

If we can do that
with rockets as well,

we don't have to keep building them
over and over again.

If you can take the rocket,
go into space,

bring most of that rocket back down
and reuse it,

you can save tens, or even hundreds
of millions of dollars per flight.

They're doing it from
the standpoint of making money.

If they bring the rocket back,
they can use it again.
That makes a lot of sense.

That brings us that much closer
to setting foot
on the surface of Mars.

'It's still hoped
NASA's Space Launch System

will go to Mars in the 2030s.

But even though the red planet
is our neighbour,

the timing of our visit
will be complicated.'

If you're planning a family vacation
and you wanna get in the car,

it's easy, right? You look at a map
and you say, "I live in city A

and I wanna go to city B and I'll
just take the highways there."

Well, great, now imagine
that city A is moving this way

at 50mph and this city
is moving this way at 200mph,
now what do you do?

Well, that is a very small problem

compared to getting
to another planet.

The time line of a Mars mission -
the scheduling if you will -

is governed by celestial mechanics,
the orbits of the planets.

It's not just you pick
a time to go to Mars

randomly whenever you feel
like going.

You've literally got to wait for
the planets to be aligned, right?

On average, the distance
from the Earth to Mars

is about 140 million miles.

But this is changing all the time
because we are both planets
that are orbiting the sun.

So, about the closest
that Earth ever comes to Mars

is a distance of about
35 million miles.

But on other times,
when we're on the opposite side
of the sun from Mars,

it can be as much
as 250 million miles.

'Launching near the time
of Mars's closest approach

shortens the journey.

So, NASA can save
on fuel and resources,

boosting the mission's chances
of success.

But this planetary alignment

only happens every 26 months.

So, if NASA misses a launch window,

it will have to wait
for over two years for another go.

But simply picking the right time
isn't enough.

Mars and the Earth
are both orbiting the sun,

so, Orion can't fly
in a straight line to Mars.

Instead, it will use what's known
as a Hohmann transfer.'

What we wanna do is,
sort of, put ourselves

on our spacecraft
in orbit around the sun.

So, we might start right here
on Earth,

launch our spacecraft...

and essentially,
we just make a nice gentle arc...

that's arcing around the sun...

so that it can naturally slide
into this orbit

and then end up on Mars.

'The journey will take
around ten months.

To get there quicker
means burning more fuel,

which isn't an option.

The Hohmann transfer
keeps fuel usage low

by pulling the craft in an orbit
that gradually intersects

with the orbit of Mars

before being captured
by the red planet's gravity.

But they need to get
their direction just right.'

The way the orbits work,

you've gotta aim in a little bit
different direction

from where Mars appears to be now.

You've gotta aim for where
it's gonna be when you get there.

This has to happen so that it can
naturally slide into this orbit

and then end up on Mars.

If we miss that precision,
then we just could end up
hurtling out into space.

'Even if NASA hits their target,

the crew has a long
ten-month journey in space.'

The human body
is just simply not designed

for long duration space travel.

'Space travel can destroy bones,

weaken heart muscles
and even mess with the mind.

Could a crew survive
the journey to the red planet?'

Out there, in a spacecraft
between the planets,

all bets are off.
It's gonna be a dangerous trip.

MAN: OK, I'm standing
about the fourth rung up.'

'When astronaut, James Irwin,
stood on the moon,

his heart beat irregularly.

Back on Earth,
Irwin suffered heart attacks

which eventually proved fatal.

A 2016 study found
that the Apollo lunar astronauts

are four to five times
more likely to die

from cardiovascular disease

than astronauts
who never left Earth's orbit.

One cause could be space radiation.'

And the radiation in outer space
won't just be damaging

the heart muscles,
but also the nervous system

and astronauts' brains
in outer space.

'Astronauts heading to Mars
will face radiation

created in the core of stars.

Some comes from our sun

when solar ejections throw out
streams of deadly charged particles.

There are also cosmic rays
from outside the solar system...

..created in supernovas -
the deaths of giant stars.

These energetic particles
race through the galaxy

at close to the speed of light.'

And you don't wanna be exposed
to too many of them.

In low doses it's not
a problem at all, really,

but in high enough doses
these things penetrate our cells

and damage our DNA,
and over the long term,

can cause really bad damage
to human bodies in space.

'The longer you stay in space,
the greater the danger.'

Remember, our missions to the moon
were on the order of a week or two.

A mission to Mars, at the minimum,

is gonna be something like, two
or two and a half years probably.

'These cosmic bullets

can cause mutations and even cancer.

New research from 2019 suggests

space radiation
will cause memory loss

in one in three astronauts
on a mission to Mars.'

It's not just a problem forgetting
where you've left your keys,

trying to come back in
through the air lock.

You do not want to be forgetting
emergency procedures.

So, we're going to
have to really consider

how do we mitigate the effects
of this radiation

to make it possible for people
to go to Mars

and actually spend some time
without being ill.

'So, the ship needs to protect
the astronauts.'

Well, you think, "I would just,
I don't know, build a spaceship
out of really thick lead."

Well, that weighs a lot and it
turns out lead doesn't protect you
from this kind of radiation.

You need something else.

Well, there is something else that
protects you from this radiation,
and that's water.

We need to bring lots and lots
of water to drink and cook with

and if we just place that water
in a layer around our spacecraft,

that can absorb the cosmic rays.

You might think, well,
you're drinking the very water

that you're using
to stop the radiation
that's causing damage to us,

won't the water
be dangerous to drink?

It doesn't work like that.

You're just taking one high-speed
sub-atomic particle

and changing it into another one
as it gets captured by the water.

Water's still gonna be safe
to drink, fortunately.

'But even if NASA can shield
its astronauts from radiation...

..space causes other health issues.'

Your bones are starting
to demineralise.

They're getting weak,
you're getting arthritis,

even in the prime of your life.

'Weightlessness during
the ten-month journey

will thin the astronauts' bones.

Muscles will waste away,
making walking on landing difficult.'

We've evolved. We've grown up
on a planet with gravity.

And as soon as you're an astronaut
in outer space,

floating around in weightlessness,
it looks like a lot of fun,

but actually your body
is deteriorating from the inside.

'Astronauts need assistance to walk
when returning to earth.

If NASA's Mars crew arrives
on the red planet

in a poor physical state,
they won't be able to function.

Intense exercise regimes in space

would help the crew
stay fit and healthy,

but we are in the dark
about the full impact

of extended space travel.

On a mission to Mars,

bodies would be pushed
to the extreme.

It's not just
the physical challenges.

Isolation is going to be a major
problem for the Mars astronauts.

They will be away from home
for at least two and a half years.

So NASA is learning lessons

from isolated humans on Earth.'

Field studies in Antarctica
are really good highlights

of what it might be like to endure
all the challenges of space flight.

Because no-one can get
to you quickly.

You're in, literally, the middle
of nowhere on a big ice sheet.

And you're just sitting there
in tents -

you have two people per tent
and about eight people -

and you're there for six weeks.

It's a really alien world.

The sun never sets in the summer.

There's nothing alive
anywhere around you,

not an insect, not a bird, nothing.

All you can hear is the wind

and the only people that you
can speak to are your teammates.

It's for this reason that NASA uses
some of these projects

as training missions
for their Astronaut Corps.

The worst part
about being in Antarctica -

which I think would be the same
in long-duration space flight -

is you really reach your limit.

I think it really highlights
the best and worst of yourself.

Even the most introverted introvert
on Earth

still needs other people to live,

and this is something that I think
we don't really fully appreciate
when we're on Earth.

What we found is that
it helps to be really open

and just communicate
your problems and so,

"Gosh, I'm not feeling
very well lately. I don't...

I'm feeling a little bit of stress.
I don't really know what to do."

And you talk to each other
and you work through those things.

'Antarctica offers clues
to how humans cope

thousands of miles from civilisation

and helps NASA to plan medicines,

communication strategies
and psychological tests

to stop mental health problems
jeopardising a journey to Mars.

But Earth-bound simulations

only provide a limited amount of data

and the teams know
that in an emergency

they can be evacuated to safety.

On Mars, rescue could take years...

if it comes at all.'

To say that sending humans to Mars
is a challenge

would be an understatement.

We could be ahead of ourselves.

Eventually we're gonna lose people
doing this and that's something
we have to face.

The question is, is it worth it?

'But there may not be a choice.

Despite the challenges,
the mission needs to be a success.

Earth is in danger...

from climate change...

..asteroid strikes...

and nuclear destruction.

We need an escape plan.'

Earth may just need a lifeboat
in the future.

We are growing very quickly

and we're using
a lot of our resources.

We're changing the planet.

We're looking for a lifeboat.

Maybe Mars is the closest
best chance we've got.

'NASA's goal is to send the Orion
spacecraft to Mars in the 2030s.

But to do that, we need a rehearsal.'

I'd love to see us go to Mars.
I would love to go myself,

but it might be nice to have
a practice before we try it.

'Where better to practise
than a destination closer to home?'

The ultimate aim
is to get humans to Mars

and one approach
is to first have a goal

of getting humans back to the moon.

'Orion will first make
the shorter trip to the moon.'

There are a lot of advantages
to using the moon.

We can test out different scenarios
for operations.

We can also test out technologies
much more close to home.

So, if something were to go awry,
we can much more easily intervene.

It's a little bit safer.
If we send people to Mars,

it's gonna be a lot harder for us
to help them if they need it.

'NASA's Orion moon missions

will be far more than
just a training exercise.

It will use them to build
a lunar outpost called Gateway,

a space station
in orbit around the moon.'

It's actually a lot easier
to do that

than trying to build something
on Earth and get it
out of Earth orbit.

'Six planned missions will build
and maintain a space station

in orbit around the moon.

It will be a proving ground
for the technology and science

that will help us get
to the red planet.

And once NASA
has ironed out any problems,

the real mission can begin.

Gateway won't simply be
a small step for man,

but a springboard to another planet.'

When we first sent humans
to another planetary body,

it was the moon
and we had never done that before,

so now we've got
the moon under our belt,

we know something about how to send
people to another planet.

We don't yet have all
the technologies that we might need

to send humans to Mars,
but we're well on our way.

'As NASA begins its journey
to the red planet,

not everyone is on board.'

A lot of people think of Mars
as our lifeboat,

just in case we screw things up
on Earth,

but we really need to take care
of our own planet.

If you wanna go there
and explore or build a base,

more power to you,
but I'm gonna stay

where it's a little bit more
green and blue.

'Even so, NASA is already
building rockets

and testing the technology.

The stage is set
for humankind's greatest adventure.'

I think we will send humans to Mars.

It's just a really, really,
really big problem

that we have to figure out
how to solve,

but we're good at solving problems.

Given the human mind
and how curious we are

and how much we like to
climb the next mountain

and achieve the next challenge,
Mars is right there.

There is something in the human
psyche that will send us to Mars

despite all of the challenges and
so, for sure, we will go to Mars.

Even though it's extremely difficult
to go to Mars,

the answer is always, yes,
if somebody asks me if we should go,

because that's
the ultimate goal.

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