Nova (1974–…): Season 45, Episode 13 - The Impossible Flight - full transcript

Two pilots fly a solar-powered airplane around the world.

Are you wondering how healthy the food you are eating is? Check it -
A mission like no other.

A plane powered only by the sun.

Set to fly around the world
without a drop of fuel.

What we do in the air,
we can do on the ground.

And this is our message.

This journey will push
the limits of technology.

It's made of fabric,
it's made of carbon,

and you can break it
with your finger.

It will test the endurance
of its pilots.

Do something wrong, just
one thing, they could die,

and you carry that for your,
for the rest of your life.

Flying solo day and night.

We never flew over the ocean.

Five nights in a row,
that's the main challenge.

Switching on
the solar generators.

They will risk their lives.

There's bad weather coming in

and then thunderstorms,

and afterwards
it's turning northwest.

Either we divert, or
we take a big risk.

To realize a dream
for our planet.

The decision we take

goes far beyond
the flight itself.

"The Impossible Flight,"
right now on "NOVA."

To fly, fueled only
by the power of the sun.

It's an audacious idea

that gave rise to an airplane
unlike any other ever built,

now embarking on a revolutionary
and risky mission.

The risk is really high.

I don't want to gamble
with a pilot in the ocean.

A lot of people can be a
little bit afraid, scared,

by the unknown
in which we are jumping.

A perilous journey,
26,000 miles around the world,

without a drop of fuel.

I think it's very dangerous.

You know, we never have the
story of those who got killed.

We have to do it
to demonstrate it works.

So someone has to do it first.

Someone has to try.

The zero-fuel flight begins
in Abu Dhabi

in the United Arab Emirates,

where the sun's energy
is in abundance

nearly every day of the year.

To have an airplane that could
fly forever without fuel.

No noise, no pollution.

That was the dream
from the beginning.

We can move up a little bit.

Just a little bit,
just a little bit... a little.

It was a dream that aviation
experts quickly dismissed.

A solar plane capable
of carrying a person

around the world

would have to be too big,
too light,

and likely impossible
to control.

There are moments where you have
to take some risks

if you want to achieve something
that has never been done.

we stay in the armchair,

and we wait until we're old
and we do nothing.

We're in the early hours
of the morning here.

The Solar Impulse 2
is ready to embark

on its ambitious
round-the-world journey.

After weeks of flight tests
over Abu Dhabi,

the airplane,
known as Solar Impulse,

prepares for takeoff.

Over 3,000 miles away,

flight operations are run
from a command center in Monaco.

Okay, André, everything
is ready.

We still wait for the final go
from the SRB.

The project is the brainchild
of Bertrand Piccard,

psychiatrist, adventurer,

and heir to a family legacy
of scientific exploration.

In 1969, I was 11,

and I saw Apollo 11 taking off
to the moon.

And I said, "I want to have
that type of life."

16 years I've been
dreaming of that,

the art of flight around
the world with no fuel.

There are doubts all the time,

When you're doing something
that nobody has done before,

the doubts are important.

If you are on a straight line
with your beliefs,

you never succeed
in something new.

Solar Impulse from Solar Ground,
confirm you get the clearance.

Okay, solar generator
looks good.

Continue with engines, then.

Have a good flight, André.

Let's start the adventure.

Okay, finally.

It's the magic, magic moment.

Main wheel liftoff.

Thank you very much.

Currently altitude 5,300 feet.

To help make his dream
a reality,

Bertrand turned
to André Borschberg...

A man known
for pushing boundaries,

both as a fighter pilot
in the Swiss Air Force

and an engineer with
a graduate degree from M.I.T.

The airplane was considered
to be possible

to be built and flown.

The challenge is how?

I mean, to make
something like this, huh?

Here is an airplane we designed,
we dreamt about.

It's a big part of, part of me.

It's really a phenomenal sight,
but crazy to believe

that it is just the sun
powering that plane here...

Their dream is to show a way
forward without fossil fuels

and spread a message about the
need to fight climate change.

They are planning on
about 12 flight legs.

With only one seat in the plane,

the pilots will have
to take turns in the cockpit.

The most difficult
will be the flights

over the world's
two largest oceans,

lasting anywhere
from three to five days.

At an average speed
of just 45 miles an hour,

the 26,000-mile trip will be
long and full of uncertainty.

Five months now, the
plane, starting this way,

if everything goes well,
comes back this way in July.

It is so much more difficult

to use these clean technologies
in the air

than to use them on the ground.

So if it works in the air,

I really hope
people will understand

that they can replace all these
old, polluting old stuff

by new, clean technologies.

What we do in the air
we can do on the ground,

and this is our message.

When you fly with the sun
as the only source of energy,

that's a completely different
world, a different feeling.

The revolutionary plane

is powered by over 17,000
solar cells

that collect and transform the
sun's rays into electricity.

That energy is distributed
to four 17-horsepower engines,

each with the daily power output
of a small motor scooter.

Any spare energy is stored in
four lithium-polymer batteries,

which enable the plane to fly
at night or under cloud cover.

The dilemma was how
to build something

big enough to collect
maximum sunlight,

but light enough to run on
as little energy as possible.

The trade-off was instability
in anything but perfect weather.

The plane is fragile and
vulnerable to the elements.

Hello, André.

Below you, you have a small
thermal inversion,

and below
this thermal inversion,

you have all this dust and haze.

At mission control in Monaco,

a team of meteorologists,

and mission planners...

Many of them
also highly trained pilots...

Monitors an array

of instrumentation
and weather models

during flight.

You can put some more power...

Lead meteorologist
Luc Trullemans

has guided long-range aviation
and ballooning expeditions

across the globe.

But this mission presents
a unique challenge.

This aircraft is so light,
so fragile,

trying to find
the places where he can fly

is not so easy.

When you have a downdraft
or updrafts,

this aircraft can break in two.

Rain, humidity, and turbulence,
forget it.

Only sun and quiet weather
and tailwinds.

On this flight, they must
steer clear of dust storms

and turbulence caused
by heat rising off the desert.

Each flight leg will have
its own difficulties,

like avoiding thunderstorms
and crosswinds,

which could blow the plane
off course.

We are excited, but there's
a lot of fear, as well.

I think the overall
round-the-world flight

you can compare
to an Apollo mission.

If you do something wrong,
just one thing, they could die,

and you carry that for your,
for the rest of your life.

Two meters.

One meter.

The most dangerous part of
every flight is the landing,

where the fragile wings are
that much closer to the ground.

This pit stop in Muscat, Oman,

is just long enough to clean
the dust off the solar wings

before the next leg
to Ahmedabad, India.

The team back in Monaco plans
on using high-altitude winds

to push the plane away
from incoming clouds.

These thin and wispy
cirrus clouds

could block a critical
amount of sunlight.

For this 15-hour flight
across the Arabian Sea,

Bertrand will take the controls.

Microphone and headphone,

and the cuffs... when it starts
to vibrate on your arm,

and this is to alert the pilot
if the bank is too, too high.

With no heat in the cockpit,

the pilots must wear
heated boots

and a sub-zero-rated parka.

Inside the cockpit,
temperatures will range

from minus 4 degrees Fahrenheit

to 95 degrees when they descend
during the summer heat.

Solar Impulse's ground crew
readies the plane

to take off before sunrise
to avoid turbulence

and stay one step ahead
of the clouds.

When I was a child, I was afraid
to climb in the tree.

Fear is there.

Either you have no fear at all,

which means you're
completely crazy,

or you have some fear,

which means
that you are not a daredevil.

It might not go well, but the
only way to know is to try.

Solar Impulse... Solar Control.

Bertrand's passion
for exploration

has deep family roots.

What interests me the most

is not to break a record,
but to do a first.

My father and my grandfather

were the first
to the bottom of the ocean,

showing there was life
in the deepest trenches.

The first in the stratosphere,

to see with his own eyes
the curvature of the Earth.

When you do the first, you
establish the first benchmark.

And from there, a lot
of new things can come out.

I flew 20 days nonstop
with a balloon.

Every day I was afraid
to fall short of fuel.

And it was almost a failure.

We just succeeded because
we had two hours of margin

with the propane after 20 days.

And that's when
I made the promise

that I would fly around
the world with no fuel.

Flying balloons is one thing.

Flying an experimental
solar-powered plane

is quite another.

Bertrand only got his pilot's
license in his 50s

and he couldn't have picked
a more difficult airplane

to learn how to fly.

Because it is so big and light,
it's particularly unwieldy.

Banking more than ten degrees

will throw the plane
into a tailspin.

And because it's underpowered,

there's no quick way
out of danger.

After 12 hours in flight,

as he approaches the airport
in Ahmedabad,

Bertrand runs into trouble.

I have oscillations like hell.

It's crazy.

I never saw Solar Impulse
do so unstable.

You said the aircraft
is unstable,

and I don't see
any turbulence at all.

It's unstable on the heading.

Did you see what happened
just now?

Yeah, I see it.

It's a heading change
of 15 degrees,

without any problem from outside.
Yeah, yeah.

From what I see on the data,

it looks just perfectly calm.


and puzzled
by what's causing the problem,

mission control in Monaco sets
up an emergency call with André,

who is already
at the Ahmedabad airport.

There he is... André, hello.

Bertrand started to say
the aircraft is unstable,

and the autopilot
cannot be connected

and had a few times sideslips
of up to 15 degrees,

and he said it's... 15?

15, 1-5 degrees, and he said
it's really hard to control.

Should we start looking
for a helicopter

just in case?

I mean, first of all,

I think he should be ready
to jump, right, yes?

Here we are looking
for a bailout area

in the area he's flying
for the moment.

If it's a pilot problem...

You know,
pilot-induced oscillation,

I think we should take time,
do everything very calm.

Unsure whether it's a problem
with the plane or pilot error,

the mission team performs
a series of handling checks

before landing.

No, now it's completely stable.


...because now I can keep the
heading without the autopilot.

Okay, Bertrand,
then the next thing,

I'd like you to extend
the outriggers

and we slowly go down.

How was the flight?

It was fantastic flight.

Fantastic flight.

Any challenges or difficulties?

Always challenges with
an experimental airplane.

You always discover,
you always learn.

The bigger challenge lies ahead.

You have to cross the Pacific.

Are you looking up
to that challenge?

Ah, yes, well, it's going
to be really impressive,

I tell you,

to cross the Pacific,
to cross the Atlantic.

It's not done yet.

You can imagine that?

It's not done yet.

This plane has the capacity
to take the rays of the sun.

I got the chance
to see this plane,

and it's a
once-in-a-lifetime moment.


After each flight

the plane must be meticulously
cleaned and inspected.

Even minor damage could pose
a serious threat.

I think it's enough.

We had a little delamination
on one of the solar panels.

No, don't push too much.

No, it's perfect.

This white spot can overheat one
of these individual cells.

If one cell gets damaged,

like with the light bulbs
in a Christmas tree,

you break down
all the others, as well.

To build the "impossible plane"

required some
unconventional thinking.

André pulled together
a diverse team of engineers

from aerospace,
Formula One racing,

even elevator manufacturing.

A lot of time where we thought

it would be impossible
to finish the project...

It's too crazy, it's too hard.

Over 13 years of design
and testing,

weight was the archenemy
for lead designer Peter Frei.

I just knew from the beginning

that it must be
a super-light aircraft.

13 years ago, the thrill,
"Wow, is it possible?

Is it not possible?"

And it was an up and down,

you know, fighting,
success, failures.

What they ultimately
came up with

was a plane with a structure
that's ten times lighter

than the best gliders.

More than 17,000 solar cells,
each as thin as a human hair,

make up the top surface
of the wing and fuselage.

These lightweight,
flexible cells

store nearly 50% more sunlight

than solar panels
on average homes.

They built a skeletal structure
that was largely hollow,

like the bones of a bird,

using carbon fiber three times
lighter than paper.

But there was one major design
hurdle they'd have to overcome.

Know exactly the capacity
of a battery,

it's a really difficult story,
not only for us,

for everybody who tries
to implement batteries

in a car or in a bicycle
or something.

To store enough energy

to keep the plane aloft
through the night,

they calculated
that the four batteries

would weigh nearly
1,500 pounds...

A quarter of
the plane's total weight.

So every other component on
board had to be lightweight

and extremely energy-efficient.

The efficiency of the
electric motors, we have 97%.

Only three percent of losses,

and if you compare this
with a piston engine...

The efficiency of the system

is between 30%, 40%, maybe 45%.

The engineers, the team,
has done an incredible job.

I mean, that's a Swiss watch
of a size of a 747.

With far fewer moving parts

than an internal
combustion engine,

the four electric engines lose
very little energy through heat

and generate almost no friction.

Like a smart grid,

the network of
solar cells connects

to the four motors and batteries
sitting behind the propellers.

The cells capture
the sun's energy

and convert it into electricity,

which flows through the grid
to power the engines.

Any excess charges
the batteries.

We charge the batteries
in nine to ten hours

and we extract the energy
in eight to nine hours.

So this is a very low rate,

and that's why we have losses

in the region
of one to two percent.

But with a power output
only slightly more

than the Wright brothers'
first plane,

the aircraft teeters right
on the edge of flight.

Failure is a real possibility,

especially on the multi-day solo
flights over the oceans.

And both pilots had to train
for the worst-case scenario.

We never flew over the ocean
five nights in a row.

That's the main challenge.

The last measure we can take
is to bail out,

but of course you want
to bail out

when you really have
to bail out.

If you do this mission, you have
to be on the positive side,

or you will never do it.

Building the airplane,
I think I'm realizing a dream

I had when I was
really a little boy,

thinking about these pilots
who were discovering aviation,

these pioneers.

I met Bertrand at the right
moment with a great idea.

Radar from Hotel-Bravo-Sierra-
India-Bravo, good morning.

I always have been a little bit
rebellious against authority.

I left home
when I was quite young.

What I learned as a fighter
pilot which was useful,

I think you are trained
to better appreciate the risk,

can come up
with the right decision.

But decisions are made
on the ground,

as well as in the air.

To find the best possible route
around the world,

the mission control team pores
over computer models

and global satellite data.

I am working on this
since five years,

so I was watching
all the airports.

There we have less rain,

less windy conditions,
less cloudy conditions.

That's the reason that we will
fly around the world

in a tropical area
during the dry season.

Their route follows a broad
tropical band around the Earth...

Between the monsoons
to the south

and cold storm fronts
in the north.

After leapfrogging across India
to Myanmar,

the plan is to get to China

in time to make their first
ocean crossing in early summer,

when the hours of sunlight
are reaching their peak.

But no matter how much
they map out beforehand,

the pilots must be ready
to change course

at a moment's notice.

In places like Mandalay
in Myanmar,

the problem is that a hangar
big enough to house the plane

isn't easy to come by.

So the team has
to be self-sufficient.

They came up with a waterproof,
windproof mobile hangar

that inflates
like a giant bouncy castle.

This 7,000-pound shelter

takes the 20-person ground crew
five hours to set up.

On the ground, the aircraft
has a lot of weak point.

It is big, it is light,
and therefore it is fragile.

It's made of fabric,

it's made of carbon, and you can
break it with your finger.

The five-day,
solo Pacific flight

will be the ultimate test,

not just for
the experimental airplane,

but also for the pilots.

If successful, it would beat
the existing world record

in any plane by nearly two days.

Five minutes before departure.


In the lead-up to the mission,

the pilots spent
three straight days

crammed in a flight simulator.

While doctors monitored their
brain waves and vital signs,

they performed mental vigilance
and stress tests.

The long duration of the ocean
flights is a concern

for mission director
and veteran pilot Raymond Clerc.

Shut down engine number two and...
And wait.

This operation is really pushing

the human performance
to the limits.

The airline pilots, they fly
always two in the cockpits.

You know, the normal flights,
they last already 12 hours,

and they can sleep
during the flight.

Our pilots, they don't
have this chance.

Because they'll be alone,

the pilots can't risk falling
into a deep sleep,

which would make them too groggy
to take over the controls

in an emergency.

So the pilots practice
a resting technique

used by the military and NASA:

20-minute cat naps
throughout the day,

adding up to around three hours
of sleep every 24 hours.

Now in Myanmar, it's nearly
a month into their journey,

and they are halfway
across Asia.

These shorter-duration flights
serve as the final test

as they get closer
to the first ocean crossing.

But first, Solar Impulse's
safety review board

must make a final call
on which pilot

will fly the critical leg
to Hawaii.

Bertrand's difficulty
flying at night

on his first flight to India

raises doubts
about his readiness

during a mission control
debrief meeting in Monaco.

Now, Bertrand, I really would
like to have more details

on this phase before landing in
Ahmedabad... what happened there,

because, you know, we had really
some stressed situation

on the ground.

I made a mistake in flying
the plane in an unstable way,

and I really scared everybody,

so I was really,
I was very embarrassed.

Not being prepared good enough.

Pilot condition must be better
than what it was.

Now, of course, I don't
have the same reactions

than a jet plane pilot, so you
also need to understand...

No, which is not necessarily
a bad thing.

While in Myanmar, the safety
review board ultimately decides

that Bertrand
needs more training

before making an ocean crossing.

André is chosen to pilot
the dangerous flight to Hawaii.

I was extremely disappointed
not to make the Pacific.

That was my dream
from the beginning.

I think I underestimated
the difficulty to fly it.

On this airplane, it's not like
in a normal airplane.

You have to be
really more precise.

I initiated the project to fly
in that airplane,

but then the same time, it's
true I'm not the best pilot.

I'm the explorer
who became a pilot.

I had to learn
to fly that airplane.

And it's not easy for me.

This decision was extremely
difficult for everybody, huh?

Especially when there are
a lot of emotions

and, and so much at stake.

If I would do the Pacific,

I knew that I had to prepare
myself very well.

When I will be in this cockpit,

there will be moments
when it will be too intense.

We will sleep,
but for very short time

of 20 minutes' resting period.

Yoga, meditation, breathing,

it's a way to reboot the system,
which is start to be congested.

When you fly jet fighters,

you have whatever power you need
to go against the winds,

to fly in turbulence
and bad weather.

Here, it's just
the other way around.

This airplane is like a leaf
pushed around by the wind.

You have to make nature as
a partner, and not as an enemy.

I think that's
an attitude in life.

In some ways, I discovered
when flying this airplane.

From Mandalay, Solar Impulse
moves on to Chongqing, China...

One of the largest and fastest-
growing cities in the world.

People say there is
too much pollution,

there is climate change,

but it's not enough
to complain about problems.

We have to bring solutions.

The same technologies

that can make an airplane fly
day and night with no fuel

can be used to divide by two
the emissions of CO2.

After seeing this, I think
in my future, my future job,

maybe I will do
something like this.

We have to think about
our children, our grandchildren.

This thing is for them.

With Solar Impulse,
we are only at the first phase.

Our goal is not
to transport passengers.

Our goal is to transport
a message.

With André, we've done six legs
from Abu Dhabi to here.

Now it's time to go to the next
level, and it's the ocean.

This is why Solar Impulse
is built.

It's five days and five nights,
solo flights over water.

It's like going to the moon.

Everything is under control,

but you still have
to go to the moon.

The challenge
with the solar energy

is to fly through the night.

The energy of the airplane
is the critical factor.

During the day,
we climb very high altitudes,

but we collect energy directly
from the sun.

And we use this altitude
at the beginning of the night

to slowly fly down...
This saves the batteries.

Minimum battery charge is...
If everything goes on plan...

Is not more than ten percent
in the morning at sunrise.

It's about an hour.

So there is not much margin,

To conserve energy, the wings
are designed for maximum lift,

and to create a high glide ratio
and low sink rate.

If the engines were turned off
at 28,000 feet,

a jumbo jet would glide
for 20 minutes,

compared to four or five hours
for Solar Impulse.

They had to thread the needle
of aerodynamic design.

The larger the wingspan,
the more energy they capture,

but the more unstable the plane
is in choppy weather.

But if the wingspan were just
ten percent smaller,

they might not have enough
energy to make it to sunrise.

Everything okay there?

Okay, let's move forward.

We are removing each gram
that we can in this airplane,

because each gram of course
is consuming energy.

I did the most weight saving

because I lost four kilos during
the last four months there,

so I did my contribution, huh.

We were never able to prove
that the airplane

can fly through the night,
so far,

and reducing weight
is reducing risk.

The lighter you are,
the further you get.

Who knows?

I mean, maybe this is
the minute which counts.

Yeah, exactly.

The Pacific is the largest ocean
on the Earth.

It's something
that is always moving,

developing, dying,
depressions, typhoons.

It's like a soup.

Since Solar Impulse must climb
over 25,000 feet each day,

the weather team has to forecast
16 different layers

of wind, humidity,
and temperature.

The most difficult part of this
Pacific flight to Hawaii

is the crossing
of a classical cold front

that acts like a wall...

that gives precipitation,

so all things
that you have to avoid.

And we have to find a hole
in that frontal system.

Every day, we are looking
for a hole there.

We're even dreaming
about a hole.

The hard part is that
after three days,

the reliability of their
forecast drops below 70%.

Flying to Hawaii takes five,
maybe six days.

When you cross that front, you
have to be sure about details.

And five days ahead,

it's difficult,
it's difficult to say.

Weather is posing a big problem

for the Solar Impulse plane...

The Solar Impulse
has been grounded in China

due to bad weather brewing
over the Pacific Ocean.

Simon, the white.

If it happens
that you have bad weather,

pilot tired,
and technology problem,

there is the biggest risk
we have.

You dream of it
almost all night,

because if there is a failure,
there is a person in there.

So from the alt to end...

It's not only that we have
the risk of losing the pilot,

but it will also change the life
of every engineer,

which André maybe doesn't
realize all the time.

Yes, I can hear you,
loud and clear.


How much, how much?

The closer we get now,
more intense it is.

How much, how much?

The first time I will fall
asleep will be over the ocean.

We all know that falling asleep
when you are stressed,

not easy, huh?

I mean, of course,
if I end up in the water,

it will be a shame,

but I'm ready
for a lot of things to happen.

There will be moment of actions,

there will be moment
of reflection.

I hope not moment of regret.

This inner voyage is really
what I'm looking for...

To go through
these different experiences.

This is the gift of all that.

You put breaking news,
take-off tonight.

Starting to be exciting.


I'm getting emotional
a little bit.


I'm so happy.

Do we have a good corridor
to get to the hole,

or we do not have a good
corridor to get to the hole?

The hole's still there,
yes, it is there.

It's more or less confirmed.

But a few hours later,
there is a change.

Take-off, we have cirrocumulus
which are new.

They were not seen before.

High-altitude clouds
that block sunlight

have moved in around Nanjing

and will reduce their energy
right from the start.

That front, that hole is moving
a little bit to the east.

I think, yeah?

On top of that,
tailwinds are decreasing.

The flight is getting longer,

and they'll have
to cross the cold front

later in their journey,

when the forecast
is less certain.

What's the flight time?

Flight time is six days
and a half.

Six plus.

Having a seventh day,
it's not acceptable for me.

If it's five-and-a-half,
okay, on the edge.

But if it's six
and something, it's... oh.

I mean, if I look at everything

I have the impression

we are pushing
a little bit too far there.

We are at seven hours
from departure.

It's tight there, it's tight.

And uncertainty due to energy.

We have too many issues,
that's the problem.

We have too many issues now.

Game over.

After working around the clock
for days on end,

it's a huge blow to the team.

They are exhausted,
but they must keep going.

The guys fighting each other
because they are nervous,

they are under tension,
they are tired.

If it's the window of the year,
we just have to do it.

We're not going to do it
for tomorrow.

I'm sorry, huh, but I think
we'll not have a solution

for tomorrow evening.

The time to prepare a distance
of such a huge window,

the weather maps and so on,
it's not done in three hours.

He's tired, he's tired.

They are tired.

Don't forget that the distance
from Nanjing to Hawaii

is almost two times Europe,
and then you're asking us,

"What's the clouds going
to be like in Poland

and in Greece
and in Ukraine?"

In three hours?
With two people!

I mean... I like my job.

I like my job.


But it was hell.

I would prefer that
we take some rest,

and tomorrow morning we start
to fight for the next one.

Fresh and rested.

It worries me very much.

If you look in
the history of exploration,

most of the big attempts
have failed several times

before the success.

While the flight team waits
in Nanjing,

temperatures inside the hangar
reach around 100 degrees.

Lead engineer Robbi Fraefel is
using portable air conditioners

and jerry-rigged tubing

to pump cold air
into the battery compartments.

Inside each of the four custom-
built lithium-polymer batteries

are 70 individual cells,

laid out like squares
of a chocolate bar,

where the chemical reactions
take place.

The cells are similar
to those used in mobile phones,

but their chemistry has been
optimized to boost performance.

The challenge with batteries

is that they rely
on chemical reactions,

which are sensitive
to temperature.

A battery likes to stay always

in the same temperature,
same pressure,

and if we change both
all the time,

it's not good for the battery.

With every ten degrees
higher temperature,

the aging is about double.

So it makes quite a difference.

Only the Pacific flight
will show the truth.

All right.

Working day and night shifts
at mission control,

they struggle to find
a way through the front,

running hundreds
of computer simulations

to come up with the best course.

In the simulation,
you play with the aircraft,

you play with
the possibilities of flight,

like if it was a game.

There are many variables
to take into account:

air traffic restrictions,

and energy demands
of both the plane and the pilot.

From one simulation to another
one you see things are moving,

so it's not good.

After a month of striking out,

the weather team finally
sees their chance.

There's a weak cold front
five days out,

but the team is confident
that the plane can cross it.

Is this now what
we were dreaming of?

We will have a nice corridor

behind this system
out to the ocean.

Three, even four days flying
in sunshine.

Now it's the moment of truth.

The first time
that this airplane

will fly with such a long time.

Okay, we move.

For the time being,
looking good.

With nothing but open ocean
ahead of him,

André will face 120 hours alone
in the cockpit...

Longer than any human
has sustained before.

He's doing this really
with a lot of his heart

and all his being.

I don't think
anything else matters.

The Solar Impulse 2 plane

is currently tackling
the most ambitious leg

of its round-the-world journey.

Once midway across the Pacific,
there's no turning back,

with no airports to land at

and no boat capable of trailing
the plane fast enough.

Even to get one man
across an ocean

will push him and his machine
to the limits.

We have now entered
the first really critical part

of the flight.

He is now starting to reduce
the power of the engines.

He starts to glide down,

and he needs to save his energy
as much as he can

until the next sunrise.

During the night,
André will slowly descend,

relying on the potential energy
he gained from altitude,

and the plane's
highly efficient glide.

But at dawn, they'll be down
to their last energy reserves.

Just a thin layer of clouds

could throw a wrench into all
their energy calculations.

And if André comes up short,

his only option is the
inflatable raft under his seat

and the hope that his GPS beacon

will guide a passing ship
to his rescue.

Wednesday there is bad weather
coming in, thunderstorms,

and afterwards
it's turning northwest.

It's a... It's a
wall in front of us?

And we have one or two layers

where we have stratocumulus.

We will reach the point
of no return

in approximately ten hours,

so we have to have
a decision by that point.

They are fast
approaching the point

at which they
can no longer turn back

because of the prevailing winds.

The good side is that the plane
flies well,

André is in a good shape,

and probably we can make it
through the first night

with enough energy.

On the other hand,
we're in deep,

because we don't know how
to cross the bad weather front

in five days.

It's a big deception, actually.

The problem is that cold front
over the ocean.

And at take-off,
we were confident

we had solutions to cross it,

and then we didn't have
a solution anymore.

André has now made it
through his first night,

but the cold front
predicted for day five

appears to be intensifying
and becoming more hazardous.

So you can confirm
that it's blocked now.

- At that position, yes.
- At that position, yeah.

The updated weather models

now show that there is
no clear passage

through the cold front.

André would have to descend

through multiple layers
of cumulus clouds,

which likely contain moisture

and will produce turbulence...
A dangerous one-two punch.

The aircraft is going
through all those clouds,

not close,
you know, with layers.

But turning back to land
also carries its own risks.

Japan is their best option
to divert,

but they have no logistics in
place for an unplanned landing.

André is in a holding pattern
over the Sea of Japan...

As they negotiate with
several potential airports.

Well, for me,
it's clearly red to continue.

It's no way.

The earlier
we announce this diversion,

the higher is the rate
of success, I would say,

to save the airplane
and the pilot and the mission.

My personal opinion is
that we have more risk

of losing the airplane in Japan

than if we try to reach Hawaii.

I don't see how
we can get permission

to inflate a mobile hangar
in Japan.

The airplane is not made

to cross a front
and fly in cumulus clouds.

Until when can we still say
we try to cross?


Either we divert or
we take a big risk.

Nobody is confident to continue,

so our position would be

to make a diversion on Nagoya.

If no window, no go.

The green energy plane,
Solar Impulse 2, stopped moving

towards its make-or-break
next destination, Hawaii.

There's no telling
how long they're going

to spend in Japan waiting
on the weather conditions.

It is an unwelcome diversion.

A small emergency crew is now in
Nagoya with the mobile hangar,

but they don't have enough
people to set it up.

And the forecast calls for rain
and heavy winds.

We need to be able to get the
mobile hangar assembled tonight.

If we did not succeed,

the risk is that we lose
the airplane completely,

and the risk is extremely high.

It's not a ten percent chance,
it's 90.

Well, what we need now
is our hangar, you know,

to prevent it from sun,
wind, and rain.

We're pretty much struggling
to keep it on the ground.

We need to put full speed on it.

Maximum speed, maximum efforts.

Just ahead of the rain,
the rest of the ground crew

finally arrives
and jumps into action.

Un, deux, trois!

The aircraft was not
just a little bit wet,

it was completely wet,

with water dripping from every
single part of this aircraft.

Well, we want to avoid
a short circuit,

because that would blow very
probably the main fuse

inside the battery.


I didn't see that.

I hope it will be okay,
but I don't know at this stage.

Maybe in three months
we're still in Japan,

and then it would be a disaster
for our flight around the world.

The team is grounded in Nagoya
for over a week

to fix the wing spar
that broke in the heavy wind

and ensure the airplane
is completely dry.

Checking if there is
a little bit of water

left in the structure.

Parts which have water inside

if the water gets frozen
when we climb very high.

André would take all the risks.


We from the engineering,

we want to reduce as much
as we can to make his life safe,

but he is a risky guy.

No panic, no panic, no panic.

Meanwhile, at mission control,

the diversion to Japan
poses a problem

for the air traffic control
specialists on the team:

a crowded airspace
with many restrictions,

which they have to negotiate.

Flying at 35 knots

in the midst of traffic
which flies at 500 knots.

So it's a little bit
an obstacle, huh?

The Japanese insist
that Solar Impulse

avoid red zones of peak air
traffic and militarized areas,

limiting their exit strategy.

We always want to wait
for better windows,

but now we have passed
the 21st of June,

and it's going to be worse
and worse in term of energy.

We are not on the safe side
if we wait.

In preparation for take-off,

the ground crew begins taking
apart the mobile hangar

as the press stands by.

But the forecast takes an
unexpected turn for the worse.

There is no high pressure there.

It's complete weather.

There is absolutely no way
to go through.

To follow something
for three days,

and ten minutes
before the take-off.


It was a bit...

There's a really a problem

in our way of working.


We're checking
if we should proceed or not.

How are you feeling?


That's the best way.

I think we really need it now,

because the spirits are
sort of not very well.

And if we now
take the plane back,

assemble the mobile hangar
again, and stay here for longer,

it's going to be quite bad

for the general mood
of the team, I think.

So that's why I believe
we're going to take off.

It's going to happen.

This afternoon I was confident.

Now I feel more like gambling.

And if he has to bail
out here, okay.

The water's maybe
already warmer,

but I don't want to gamble
with a pilot in the ocean.

I'm not confident to letting,
taking the risk of your life.

It's very difficult

to go against the inner,
inner feeling.

There are two
terrible situations.

The worst is to be
in the middle of the Pacific

and see that it closes,

and to lose the plane
and you jump.

The other one is
to be on the runway

and to see that it closes, and
this is exactly what we have,

but it's not as bad
as if you are

in the middle of the Pacific.

I feel that you went over
the tipping point

in terms of feeling,
and so it must be right.

But it's a terrible situation,
and I imagine for you...

I'm so sorry for you, André.

You... you cannot imagine...
Don't be sorry, huh?

You cannot imagine
how sorry I am for you.

You are in that cockpit,
you are ready to go.

When I said we have to stop,
Michael told me, "Thank you”"


So confirm, flight is canceled.

We go back to the tents,

but that's... that's life, huh?

A lot of hurdles.

Big hurdles.

We tried everything we could.

And we, we just...

We just failed
the last centimeter.

The last centimeter.

Always trying to make it,
to make it work,

and then you see that all that
work is kind of for nothing.

I have to admit
that the last weeks, I was...

I was losing, losing faith.

With the Summer Solstice
now behind them,

the daylight hours and available
energy to cross the Pacific

are steadily decreasing.

The monsoon is really picking up
here in Japan,

which means rain,
it's also the risk of a typhoon.

So what we are facing
if we cannot leave

over the next few days to Hawaii

is being hit by a typhoon,
lose the mobile hangar,

and of course,
lose the airplane.

We will always have
an unknown thing.

I think this is
the nature of a forecast.

It's a forecast,
it's not the truth, yeah?

Either we try to cross
an ocean or not.

At last, it looks
as though they can.

A promising five-day window
of clear weather opens up

from Nagoya to Hawaii.

You know, it was so embarrassing
to have André ready to take off,

all the press watching,

we had to cancel
at the last minute.

And this time
we want to avoid this.

So we're not telling anybody.

And once we're in the air,
if it works,

then we say,
"Hey-O, coco, here we are.

This time it's going well."


Third attempt,
ladies and gentlemen.

Third time that we try to move.

Whatever happens, we go.

I am committed.

Completely committed
to this flight.

Point of no return
is already passed long time ago.

Friday, we were both super-,
super-depressed in Tokyo.

This might be the end.

And I'm, it's not sure
we're going to still make it,

but if we make it to Hawaii,

at least we've done
the hard thing.

We are just getting ready,

and we try to take off
at 3:00 a.m. sharp.

This time it seems better,
so we try again.

Looking fine from Nils.

Go to standby now.

Then, just minutes
after take-off, they hit a snag,

this time with the plane's
autopilot surveillance system,

known as the M.A.S.

There was a short
M.A.S. failure.

Okay, copy.

There was a short M.A.S. fail.

If we do not find out why it
happened or what triggered it,

we should not continue
for the Pacific.

The biggest concern is...
The problem is the M.A.S.

That's the,
that's the killer one.

The M.A.S. is the system
controlling the autopilot,

which is giving false alarms
and waking up André

each time he wants to sleep.

The M.A.S. wakes up André
if there is a significant change

in the airplane's heading
or bank angle.

The false alarms
are not just annoying,

they keep André from getting
the rest he needs.

If the system fails completely,

he will have to rely on
mission control to wake him up.

But there's a chance he could
lose satellite communication

out in the middle
of the Pacific.

So you want to continue
to Hawaii?


Knowing that the monitoring
is not working?


And you still... you...

It makes life a little bit
more complicated.

We'll need monitoring
from the ground.

The risk is really high.

The risk is really, really high.

We have 55 minutes
before the point of no return,

and we don't know
what is causing this,

and we have no idea.

I mean, it could degrade.

We still don't know
the cause of the problem.


If we go back to Nagoya,

I'm sure we would find
another window,

but the season is not over.

A bloody situation.

If we go back to Japan,

I think it's the end
of the project.

With the electronics

the engineers have serious
concerns about continuing.

But the pilots are concerned

about what another
aborted flight could mean

to the future of the project.

Now we just need to know if
André wants to continue or not.

And what do you think
it will take for him to decide?


Not only as a pilot,
but for the project.

It's the most serious crisis
they have faced,

leading to a sharp division
within the team.

We have an aircraft, which
is not nominal. Yeah.

Things will break
during this journey,

and if we start the journey

already with one
redundancy down,

that's not a good
starting basis.

I would recommend to go back.

Going back to Nagoya in
the season of typhoons

with the possibility
of destroying the airplane

on the ground, in term
of overall project,

it's more risky to come back
than to continue.

Personally, I have a very good
feeling I can do it.

We have an airplane which has
a very good source of energy.

Very good storage.

If you decide to continue,
as a friend,

you have all of my support,
but as an engineer,

I would say we have to go back
as we have the choice.

A lot of people can be
a little bit

afraid, scared,

by the, by the unknown
in which we're jumping.

I was very often in my life

in these type of situations,

and I tell you it's worth it.

But the decision we take
goes far beyond

the flight itself.

We have now the possibility

to do what nobody has done.

When Chuck Yeager

broke the speed of sound,
he had a broken rib.

All these things were
absolutely incredible feats.

I think it's very dangerous,
too, with this heroic speech

to encourage people
to take a wrong decision

because we never have the story
of those who got killed.

This is a hard project.

These are difficult situations.

I guess I do it because I do
this airplane quite well,

and what can be done
and what cannot be done.

Nobody in the future
will understand

that two managers
can go against a whole team,

and you really force us
to support something

that nobody wants to do.

I just want to make
one point very clear.

There's only so much we can do
to support you

from here, from the ground.

So when you decide to go on,

you will be on your own
up there.

This is Capcom speaking.

We have to start the climb now
if we want to have a chance

to respect the profile.



From an engineering
point of view,

it was the wrong decision.

That you still can make it
is, like, I don't know,

driving with a flat tire.

We have to be lucky,
from a certain point of view.

But it's... It's their decision.

We saved the project by deciding
not to return to Japan.

On the other hand,
we have some of the engineers

who are so pissed off

because we did not follow
their recommendation.

They want to leave the project,

and I don't know
what will happen after Hawaii.

As morning comes,

André continues to be awakened
by false alarms.

So I lost one source
of information.

Well, let's see, we are
currently rebooting.

A lot of wake-up calls
in this, in this airplane.

This M.A.S. system,
which monitors the aircraft

while the pilot is resting,
is behaving erratic.

We had it working
in the beginning,

then it produced a failure,
so we shut it down.

We tried again.

We don't really know what
the status of the system is.

The first night was
about digesting,

I mean, the emotion
of the first day.

It was really intense.

When I look out, you know,
I see the moon,

I see the clouds,
and here I am over the Pacific.

I think a feel a bit higher.

On day two, there's a worrying
new development...

The plane's batteries
are overheating.

We need to burn more energy.

It is a risky game to... I know.

Due to the flight profile
we did on the first day,

the batteries got too warm.

If it sums up over the days,
it can become really too hot.

They can start to burn.

Climbing too quickly
on the first day

increased the demand
on the batteries,

and they began to overheat.

The risk is that this could
degrade their performance.

Today the challenge

is to keep
the battery temperatures low,

as low as possible.

So we will adjust
the climb profile

to not have too much current
going into the batteries.

It's turbulent
since I think about one hour.

We are climbing again at 9-0,
and we'll see if it's better,

but it costs energy.

That's exactly what
I was afraid of.

Still some time
until the next sunrise.

Turbulences during the night,
which means a lot of work,

of course no auto-pilot,
of course no sleep.

I really started to work hard
to see how we could get out.

So we climbed again,
and when you climb,

you use the energy
that you need for the night

so it's a little bit stressful.

We're monitoring everyday

how many resting periods
is he getting.

For the first two nights,
he had three hours of sleep.

That's okay,

but we don't know
what's going to happen

on day four if you keep
that rhythm, and day five.

So we climb every day
the equivalent of sea level

straight up to Mt. Everest.

No acclimatization.

If you don't have enough oxygen,

there's the risk of hypoxia.

Within 60 seconds,

will lead to
a severe degradation

in your ability to understand
what's going on around you.

You become euphoric.

So not only are you
in a dangerous situation,

you're not able to recognize
the situation

and you feel good about
not recognizing the situation.

Then very quickly
you will pass out.

We're watching to see how his
body is absorbing the oxygen.

Is it actually getting enough?

You're constantly listening
to this...

You hold your breath.

And hope he breathes.

And then you keep going.

Pilot status.

Mood, he is exhausted.

Not as good as it was.

We have a pilot that is starting
to show signs of fatigue.

We have batteries that will not
take a lot more abuse.

We see that all the systems
are stressed, yeah?

The flight is not over.

Quite intense.

You have to perform because
it's real-time, you know.

As an engineer, you are used to,

I solved the equation today,

"and if I don't solve it today,

then I'm going to solve it

And this is totally different.

I'm kind of happy
that it's soon over.

So now a preparation
for landing.

I was thinking about all this,
and I cried.

Cried loud.

It was a little bit ridiculous,
you know,

alone in the cockpit crying,
everything was going well,

but it was so, so intense.

And André, you have
some kind of headache?

No, not headache,

but something has
been growing on my head.

Really strange.

Okay, but I cannot see it.

Do you have the face view?

And now... oh, okay.

He looks terrific, yeah.

I don't know what happened.

I spent too much time
in this damned plane.

Ça va bien, ça va bien.

He can feel every,
I think, element in the plane.

He knows which wings
is vibrating.

I think he was a bird
in another life.

A plane powered only by sunlight

makes history today

in a five-day journey
across the Pacific.

This will be the furthest
a solar plane has ever flown,

as well as the longest-lasting
solo flight in aviation history.

I've never been to something

this historical before.

Too young to see other things,

just the right age to see this.

It's absolutely beautiful,

and the latest wind from the
ground crew is 0-4-0-3 knots,

in the axis.


To confirm, you have the landing
and promotion lights on.

It's nice to put them on.


Flight path secure.


To fly with the sun,

you need to be
extremely energy-efficient.

And this efficiency
can be used everywhere.

This is why it's
a historic first for aviation,

and a historic first
for renewable energies.

Will you make it
around the world?

Are you confident of that?

It's an attempt.

We cannot be overconfident.

I received so much support
from people I didn't know,

and the beautiful message.

So when you read this, you know,

you know that people are
supporting you.

And I was carried by all this,
I'm sure.

All of us were very lucky
to have the pilot back,

but when this decision came up
that André and Bertrand

want to continue,

it hurt us in the soul that
somebody decided against us.

I was fully in opposition
to André and Bertrand.

André is pushing.

We always had these discussions
and fights,

"Why do you tend to go
beyond limits all the time?

"We, engineers, tried to set
reasonable limits

"that you survive, "and
you, your target is always

to sort of prove us that we set
the limits too narrow."

If everybody is telling you
that you are a hero,

I think it's good also for them
that there are people

who try to pull them back and
on the ground from time to time.

Despite the divisions
and problems with the plane,

they are still hoping to get
around the world this year.

Their immediate worry
is the health of the batteries.

The concern about the batteries
is that they are damaged.

We heated up the battery in only
one hour by about 20 degrees.

At the moment, we are on
the worst-case scenario

where we have to exchange
some cells in the batteries,

which is...
this is a nightmare.

We have overheated
the batteries.

More cells are damaged
than the spare parts we have,

so the logical consequence

is that we will stay here
until next April

where we can continue.

The flight from Japan to Hawaii

left scars on many
of the engineers.

I think, for everybody,

to complete this flight
around the world

is extremely important.

It's part of their life.

I mean, they all stayed.

During the break, new batteries
had to be manufactured in Korea.

The engineers realized that the
batteries were over-insulated

against the cold

and heating up too much
in warm conditions.

So they engineered
a two-way valve system

that allows the pilot
to let the heat out.

Last year, I was too much
emotionally involved.

Ça, c'est bon.

I was thinking,
"It's now or never."

I was completely
the head under the water,

which is really not good

for flying an airplane
over oceans, you know?

I've flown 20 days in a balloon,
but we were two.

Flying alone,
it's something different.

To prove he could fly safely
over several nights,

Bertrand trained to rely more
on instruments

than on the horizon.

One, two, three, the fourth one.

I will never be as precise
as a jet fighter pilot.

This you cannot get at my age,
but at least to do it correctly.

Climb 174.

After studying potential routes
from Vancouver to Mexico,

the team locks in on a three-day
flight path to Moffett Field,

home of NASA,
just south of San Francisco.

We see a weather window
for Moffett right now.

It looks good,
it's a short flight.


We'll only confirm
really tomorrow,

even on the day of take-off.

It comes from the house
of Charles Lindbergh, in Maui.

A beautiful gift.

This is more for the Americans
than for the Europeans,

and it's "Star Trek,"
Captain Picard,

who is inspired from the
twin brother of my grandfather.

It was a challenge
to be an explorer

that would be different

than my father
and my grandfather,

not to just redo the same.

The wind is at the limit,

so for the time being,
we don't go out.

I was doubting sometime,
is it my way?

Because I'm also interested
by psychology, spirituality.

Good Morning, Bertrand.

This is Christophe.

How are you?

I'm fine.

I had four hours of good sleep.

I woke up before
the alarm clock.

I'm in perfect shape.

Very good, very good.

My father and my grandfather
gave me the drive

to be an explorer,

but my mother showed me the need
to give it meaning.

We were extremely close,

like two human beings
in quest of understanding

why we were on this Earth.


Have a great flight, Bertrand,
and enjoy it!

And don't forget to come down!

People are always thinking,
I am the wife,

I should have this fear.

When Bertrand did his
round-the-world balloon flight,

our children were very small.

At this age, children,
they don't have any fear.

They are just living
the present moment,

and I just realized I should not
give them this fear.

The flight is long for him, huh?

This was one
of his main question:

If I don't sleep,
how can I survive?

First sunrise
over a sea of clouds.

That's the sunrise
I will remember all my life.

Switching on
the solar generators.

I can show you my little house.

That's the kitchen
where I prepare my food.

The toilet inside the seat.

That's the cellar.


Estelle, Oriane
and Solange, Michèle.


Hello, Solar Impulse,
hello, Captain Piccard.

Good afternoon,
Mr. Secretary-General.

I speak to you from the cockpit
of Solar Impulse

in the middle of the Pacific,

flying on solar power.

All this airplane is like

a smart grid, collecting energy,
distributing energy,

with very, very high efficiency.

And this is exactly
what the world needs.


You look like an astronaut
in the moon.

Thank you,
Mr. Secretary-General,

and congratulations
for what you are doing.

The world will remember it.

While you are making history,

we have also made history today.

More than 175 countries signed
the climate change agreement.

Thank you for your leadership
and inspiration.

All the best to you...
Bon voyage.

I think I had more butterflies
in the stomach

before that live transmission
than when I took off

with Solar Impulse
three days ago.

The sun's going to arrive
in a few minutes

to carry me to San Francisco.

It's beautiful.

Moment extraordinaire.

14 last years of attempts,
of setbacks, of problems,

it was worth going
through all these moments

just to be here, now.

Il est où, Stéphane?

The thing that amazes me
is the size,

and especially given
the low weight.

This is the moment

where you start to see
electric power taking off.

Sometimes, you know,
there are people who will say,

"Why do you fly
with a solar airplane

"like Solar Impulse?

"It's expensive, it's big,
it's slow, only good weather

and only one person in it."

Silicon Valley, nobody ask.

Everybody knows, understands.

When Solar Impulse
landed yesterday in Phoenix,

it was just in front
of a cemetery of old airliners.

It's very sad.

A lot of these airplanes
will never fly again.

You know, they get dismantled.

This one lost, you know,
the left eye.


Of course, it's normal.

All this will be replaced
by better technologies.

But still, in fact,
I feel emotions when I'm here.

An airplane is not just
a piece of metal.

It represents much more.

When people think
fuel is forever,

they forget the Gold Rush
100 years ago,

and the ghost towns.

I'm not saying Solar Impulse

will replace an airplane
like that very soon.

In ten years' time,
we have airplanes

flying electric with batteries,

plugged in the grid
before take-off,

and they will transport
50 people.

Today you make electricity
with solar panels in Dubai

cheaper than with gas.

Ladies and gentlemen, you are
now doing your last flight

on the combustion-engine

In the future,
you will be flying electric.

At mission control,
there is no time off.

Getting across the U.S.

as fast as possible
so they can cross the Atlantic

during the peak energy days
of summer.

They will have to navigate
around the turbulent air

over the Rocky Mountains,

the unstable thermals
of the Southwest,

and the Midwest's infamous
Tornado Alley.

Well, we arrived
in the tornado season.

Every two or three days
there are thunderstorms,

and those thunderstorms,
they can lead to tornadoes.

The local news came on and
said this was landing,

so I went outside
and watched the skies

to try to see something weird.
All night long.

I don't buy into
the global warming deal,

just to be honest.

We've had oil and gas
for all these years.

But if they can make stuff

then I'm all for that.

They can obviously
make it go faster.

Because I think you can
drive faster

from Phoenix to Tulsa
than he flew,

but it's a start.

Just as the Wright brothers
did before them,

this team hoping to show
anything is possible

with the right resolve.

But in Dayton, Ohio,
a problem with the mobile hangar

reminds them
just how fragile their plane is.

Today, we had a failure
in the electric system

of the mobile hangar.

It deflated.

Touched the airplane,

it can destroy the airplane,

The mobile hangar was laying on
the tail of the aircraft,

slowly going down onto the wing.

I just would like to hear
if there is a visual defect.

We have no idea what,
especially here,

I'm not so afraid,
but from the wing.

Until we see there is a problem,

it's stupid to cancel
the flight of tomorrow.

Don't even think about it.

I hope we can fly again.

I think that's where we are.

Even though there may be
no signs of external damage,

the weight
of the collapsed hangar

may have cracked
the plane's internal structure.

What we try to avoid is that
we get into a panic stage.

Bertrand is pushing, of course.

Don't push this.

Don't push,
this is not the moment.

We try, we go step-by-step.

So for me, for me,
it's a non-event.

It's not a non-event, yeah?

Be careful what you say.

We are in deep.

In really deep.

Maybe there is nothing on the
airplane, but we don't know.

This is an airplane
which is certified

to fly over the major cities,

and you don't play with safety.

That's the responsibility
of the engineers.

And I don't think
we'll come with an answer

which is black and white.

To be sure the plane
has no structural damage,

they must calculate
the suspected load

on the tail and wing.

This project is too big

to be run
just by personal wishes,

but this is very new for me.

After crunching the numbers
through the night,

the engineers finally decide
that the plane is safe to fly.

We had a couple of explosions,

very often because
of our character,

maybe because of our egos.

And it was a hard process.

I think we understand
that we bring to each other

much more than the difficulty
that the relationship creates.

I don't think we're ever
going to laugh

at the difficult moments
we went through.

With André, we are together
since 13 years in this project.

We're very proud
that we didn't split apart,

that we didn't have any divorce.

That we could learn so much
from each other.

As they arrive in New York,
Bertrand is reminded

of the triumphs and struggles
of his father, Jacques Piccard.

In 1969, my father arrived
with his submarine.

After the drift mission of one
month in the Gulf Stream,

he arrived in front
of the Statue of Liberty.

I was 11 years old,
so happy and proud.

You know, altogether, he had
50 projects of submarines,

and only five got some fundings.

I saw my father worn out
by all these disappointments.

He told me, "Don't feel obliged
to continue my work."

Now the Atlantic Ocean
looms large.

Bertrand faces perhaps the
biggest challenge of his career.

It's smaller than the Pacific,

but with notoriously
harsher weather.

There's a cold front
in their way...

A wall of clouds
and unstable air

that's risky for the airplane.

After days searching,
mission control in Monaco

notices a narrow corridor
of clear skies starting to form,

leading to Sevilla, Spain.

The corridor
that we've been following,

and that's really,
it's really small.

Between all the bad weather
to the north, to the south.

But they only have so much time
before it closes.

Let's go for the Atlantic,
my friends.

The Atlantic is going to be

probably the greatest flight
of my life.

I don't want to put the pressure
and say,

"Oh, I met Charles Lindbergh
when I was a child,"

and imagine how important it is
and how symbolic it is.

I want it to be natural.

I want it to happen
in a peaceful way.

When you are in
the middle of the unknown,

you have these moments of grace.

You are, at that moment, like
you would like to be forever.

So now you are challenging
your fighter pilots.

I love my fighter pilots.

Did I show you my map already?

Maybe André will not like
this map as much as me

because the Pacific
is very small on this map,

but the Atlantic is very big.

In front of you,
the window is still open.

Behind you,
the window has closed.

Bertrand makes it through
the corridor just in time.

Next, he must harness the
powerful winds of the Jet Stream

to propel him
towards the coast of Spain.

Jet Stream is the conflict

between cold air in the
upper levels and warm air,

and they are pushing
against each other.

At 20,000 feet,
we may have 50 to 60 knots

pushing the aircraft
to the east to Europe.

And now we will fly
very fast, huh?

An airplane powered
solely by the sun

has made aviation history
after an almost three-day flight

across the Atlantic
from New York.

From Seville, the aircraft
will continue its journey

back to Abu Dhabi,
where it all began

for this extraordinary project.

When I flew yesterday
over the pyramid,

they were just emerging
out of the haze.

I guess it was exactly the same
as they were 4,500 years ago.

They believed in eternal life,

and for me, it's a symbol
of eternity.

Solar Impulse is also intended
to be a symbol:

a symbol about sustainability,

a symbol about the potential
of renewable energy.

If you build something
like this,

which is done to be forever,

it's not necessarily the
solution which we would go for.

Sustainability means that
you stay in line with nature.

And I'm not sure in fact
the way we build

takes this into account.

If you don't change
the situation,

the world will dictate you
the future

and not the other way around.

There are so many mixed thoughts
and feelings right now

that it's difficult.

After this flight, it's over,

so it's like a family
that's going to split.

But there is the message,

and what we have to do
out of this flight,

and I'm working since years
for that, and for that moment,

and I want to be sure
not to waste it.

After 16 months
and nearly 25,000 miles,

the last leg to Abu Dhabi

presents an unexpected
final challenge.

They knew it would be hot
in this desert region,

but now an extreme heat wave
is posing a dangerous threat.

We never flew

with such a light aircraft
in such conditions.

Extreme conditions.

Above the Saudi Arabian

night temperatures at 3,000 feet
hover around 90 degrees.

Mission engineers worry
that critical systems on board,

which are not certified
for such heat,

could completely shut down.

But their bigger concern
is energy.

As the hot air
cools during the night,

it creates strong downdrafts
of wind

that push the plane
to lower altitudes.

I didn't expect such an issue
at the end, with the last leg.

The downdrafts are so strong

that he cannot fly
through the night.

He will use so much energy
to stay at this level

that he cannot survive
during the night.

Take-off conditions on
Sunday are not good,

and we will have extreme
thermals overhead.

I believe that each
of the problems can be solved.

There is a danger
that you overheat equipment,

and at the end,
you have a failed aircraft.

After several days waiting,

the severe downdrafts
appear to be subsiding.

It looks like the flight
is back on.

As we are quite tight on energy,

timing is critical.

Every day there are
cumulus clouds

that are really, really high.

Is the, is the pilot healthy?

This time the pilot is a little
bit green, I have to say.

You mean it's stomach problems,

Yeah, yes.

I'm a little bit weak,
but the general...

General situation is good.

Okay, then drink a lot of water,
but you're the doctor, not me.

Keep in mind that the flight
is not easy.


No, it's a difficult flight.

I know.


Everything is different
from what we have planned.

It's adventure.

It's not a business plan.

Nicolas Lugeon.

Claude, Staub,
Jerome, Paige, Eoin.

Bertrand, are you okay?

It's not the moment
I'm the healthiest in my life,

but it's still under control.

Still under control.

I hope it's the last taxi.

Because if it is, then it's
fantastic moment right now.

I've never been in a project

that gave as many moments
of elation

and moments of disappointment.

It's really strange.

It's really difficult.

As we told you, the night
might be quite tough for you.

I would like to drink,
I would like to pee,

I would like to hopefully
re-evaluate my clothing

because I'm too hot,

but I just can't
do anything else.

During the night, Bertrand
must try to ride the updrafts

and avoid the downdrafts that
will sap his energy reserves.

Once you have an updraft,
just go with it,

and don't fight
the downdraft with power.

Just let it go.

It was not such a bad idea
that you had 17 years ago, huh?

You know what, it became
a good idea

thanks to all the people
who supported it.

We can't save the planet
with one plane

flying around the world,
but maybe it inspires

many people to start
solving problems instead.

Then maybe it was worth
all this stress.

We are late.

We really have to move,

How you will enter?

I don't have a...

You don't have a permit
to enter.

I will go, I'm the pilot.

I tell you I will go.

You can shoot me, I will go
and I will take my team.

When André took off
the ninth of March last year,

I was thinking,
"We are completely crazy."

And a year and a half later,
you see the result

of what our team has achieved

because they accepted to dream.

And when you see
the state of the world today,

it is a crime
not to try something.

Not to try to increase
quality of life

on this planet.

We love to fly.

For others, it's an art,
in science,

in the community,
but we have to try.

What I remember is to be
on this runway 15 months ago

exactly at this position,

ready for the flight
around the world.

Not knowing what will happen,

not knowing how much time
it would take, just go.

Just go and start.

And seeing the airplane coming,

it's like slowing down the time.

It's really, really strong.

Whoa, God, we did it!


This "NOVA" program
is available on DVD.

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