Original subtitles

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 earthlike environment

we see in our solar system.

So we're not going to leave it alone.

We're going to try to do this.

But conquering our planetary neighbor

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 going to be in one piece?

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

Are we doomed to fail in this endeavor?

Captions by vitac... www.vitac.com

captions paid for by discovery communications

♪

The red planet... earth's neighbor

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 got to take every precaution

as NASA's astronauts arrive at Mars,

they'll 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 an hour,

leaving a deep, black scar on 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 stick the landing.

And for NASA's first crewed descent to Mars,

the space agency must learn from these mistakes.

But as the crew hurdles toward 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.

So 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's 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.

Mars is different.

4.5 billion years ago,

Mars and earth formed from dust and gas in space.

Mars forms where building materials were scarce.

Its growth was stunted.

So Mars is much smaller than the earth.

It's a factor of 10 smaller than the earth,

and that factor of 10 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.

4 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 charged 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 going to be too pleased

if they're gonna be bouncing onto the surface

in an airbag, rolling to a stop, right?

To land people on Mars, NASA will need some new tricks.

The 2020 rover will overcome the challenge with the advanced

supersonic parachute inflation research experiment,

a.s.p.i.r.e.

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 going to work for people.

A human lander will weigh far more

than the 2,300-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 tilt the nose of the lander towards the martian surface

aiming for the thickest part of the atmosphere

close to the ground.

Then they pull up at the last second

using friction from the atmosphere to slow the craft.

Descent engines switch on for the final touchdown.

♪

Is this a crazy idea?

I mean, yeah, it's a little bit weird.

I don't know if we'd really think about it,

doing something like this,

but, I mean, you've got to think outside the box sometimes.

Right now, NASA's plans 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 the 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 your space habitat

and shaking yourself off.

It's gonna get in your space suit.

It's gonna coat your visor.

It's going to cover your solar panels.

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

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

300 feet.

Through the '60s and '70s,

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,

and resulted in false instrument readings.

It even made the astronauts sick.

You don't want to 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 the dust itself.

You don't want to do that.

The red planet is covered in sticky dust,

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

...the Medusae Fossae formation.

When the 600-mile-long volcanic deposit formed

3 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 large 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 firsthand

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, well, 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's astronauts do make it to Mars,

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

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 a static charge.

So you get these electrical flows that occur.

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 lightning discharges in those volcanic plumes

from this same charge transfer.

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

that means sparks are going to fly,

which is really terrible for operating instruments.

To survive on Mars,

the settlers are going to need a protective shelter.

The keyword 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 really 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 dust storms.

If you actually then seal them, you can fill them with air.

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 choices,

and they can be built by robots

before the settlers even arrive.

And we could even send 3-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.

Even with shelters, the settlers will still need

to eat, breathe, and drink.

But there is no food, no breathable oxygen,

and no 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?

♪

Humans have evolved to life on earth.

We have oxygen to breathe, water to drink, and food to eat...

everything we need to survive.

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 is an alien world

that's going to try to kill you at every step.

It's far away. It's cold.

There are just so many reasons why

we really 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 earthlike,

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' dust looks really benign.

It looks kind of like dust you would find in Southern Utah.

But it turns out it contains

a lot of something called perchlorate,

and these materials are really toxic to human life.

Perchlorates are chemicals formed by electricity

produced in martian dust storms.

And they make up about 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 and 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 yet ready.

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

and NASA has the solution... hydroponics.

Hydroponics will provide all the food

a martian settler might need.

Instead of growing in soil, the settlers 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,

then we still have this problem

of needing lots and lots of water.

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 1,500 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' 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 going to go.

Even if NASA's astronauts can turn the martian ice

into drinking water, without another resource,

settlers will be dead in three minutes...

oxygen to breathe.

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 color.

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 I.S.S.,

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 got to 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

the Mars oxygen in-situ resource utilization experiment,

or M.O.X.I.E.

M.O.X.i.e. 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 M.O.X.I.E. Can't make enough for a crewed mission to Mars.

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 really challenging.

I think we're still asking ourselves this question,

how will we do it?

♪

NASA plans to put boots on Mars.

To achieve this, you need to carry a lot of stuff.

You need oxygen, you need medical supplies,

you need food, you need stores of water,

you need some fuel if you want to come back,

and all this has to be packed into an incredibly tiny volume.

NASA's solution... 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 is 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 anymore. We stopped making them.

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 S.I.S., is the rocket

that's being designed to carry Orion off of earth

and beyond low 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 going to 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 s.I.S. 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 of 2017.

Now it's scheduled for the end of 2020.

Critics see the s.I.S. As a waste of money,

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

It's still hoped NASA's space-launch system

will go to Mars in the 2030s.

But even though the red planet is our neighbor,

the timing of our visit will be complicated.

If you're planning a family vacation

and you want to get in the car, it's easy, right?

You look at a map and you say I live in city "a"

and I want to go to city "B"

and I'll just take the highways there."

Well, great.

Now imagine that city "a" is moving this way

at 50 miles per hour,

and this city is moving this way at 200 miles per hour.

Now what do you do?

Well, that is a very small problem

compared to getting to another planet.

The timeline of a Mars mission,

the scheduling, if you will,

is all 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 plants 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' 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'll have to wait 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'll use what's known as a Hohmann transfer.

What we want to 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 10 months.

To get there quicker means burning more fuel,

which is not an option.

The Hohmann transfer keeps fuel usage low

by putting the craft in an orbit

that gradually intersects with the orbit of Mars

before being captured by the red planet's gravity.

But the crew will need to get their direction just right.

The way the orbits work,

you've got to aim a little bit different direction

from where Mars appears to be now.

You got to aim for where it's going to 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 hit their target.

The crew still has a long 10-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 cruise survive the journey to the red planet?

♪

NASA plans to put humans on Mars in the 2030s.

Rocket technology will be pushed to its limits.

But the greatest hurdle is our own fragile bodies

out there in a spacecraft between the planets,

all bets are off.

It's going to be a dangerous trip.

Both hands down to 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 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 deep-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 death of giant stars,

these energetic particles

race through the galaxy at close to the speed of light.

And you don't want to 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 ourselves

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 going to 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 to three astronauts on a mission to Mars.

And it's not just a problem

of forgetting where you've left your keys.

Trying to come back in through the airlock, 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, "well, I would just,

I don't know, build a spaceship out of really thick lead.

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

won't the water be dangerous to drink it?

It doesn't really work quite like that.

You're just taking one high-speed subatomic 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 demineralize.

They're getting weak.

You're getting arthritis even in the prime of your life.

Weightlessness during a 10-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 arrive 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're in the dark

about the full impact of extended space travel.

On a mission to Mars,

bodies will be pushed to the extreme.

To say that sending humans to Mars

is a challenge would be an understatement.

We could be ahead of ourselves.

Eventually we're going to 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.

We know that, over time,

this planet is not going to be habitable.

So we really should consider

if there are places we can go outside of earth.

♪

NASA's mission to Mars

will be the toughest undertaking in its history.

The launch from earth will be a monumental challenge...

...the journey to Mars filled with danger,

and survival on the red planet will be a test

unlike anything NASA has faced before.

It's easy to make a bullet list

of of why going to Mars is hard.

And that's going to be a long list,

and those bullet points are going to be scary.

A lot of these are serious problems.

NASA's mission to Mars needs to be a success.

Earth is in danger

from climate change

to asteroid strikes

to 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.

Despite the challenges,

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 little bit of practice

before we try it.

Where better to practice 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, and 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,

you know, it's going to 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.

They'll 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 the 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.

It'll be 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 want to go there and explore

or build a base, more power to you.

But I'm going to 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.