All language subtitles for Cosmos.Possible.Worlds.S01E08.The.Sacrifice.of.Cassini.1080p.HDTV.x264.AAC.MVGroup.org.en

MAN (over radio):
Systems this is prop.

I read you 500, do you read me?

TYSON: These people are
watching their life's
work come to an end.

MAN (over radio): The team
is on its way to point.

TYSON: On another world.

MAN (over radio):
All right. Roger that.

TYSON: They were all young
when they sent her on her way.

These men and women have been
traveling vicariously with her
for more than two decades.

And now, her work is done,
so she must die.

But before she
takes the fatal plunge,

they've given her
one final, epic challenge.

(theme music plays)

♪ ♪

♪ ♪

TYSON: Gravity has
a big bag of tricks,

none lovelier than
the ring systems of worlds.

Our own solar system, alone,
has four ringed planets.

This one, with the
romantic name J-1407B,

is the first we've
found circling another sun.

Why haven't we found more
ringed planets in our galaxy?

Is it that the
rings are so unusual,

or are the methods we use
to find exoplanets not very

good at seeing the ring
systems that may surround them?

J-1407B's ring
system is so vast,

that it eclipsed
its star for days.

These rings extend across an
astonishing 112 million miles.

They would more than
fill the distance between
Earth and the sun.

But as enormous as they are,
they're shockingly thin.

If the ring system of J-1407B
were the size of a dinner plate,

it would have to be
100 times thinner,

as thin as a human hair.

This surprising contrast
between the immense territory

of a ring system,
and its thinness,

is just as striking
in our own solar system.

The outermost ring
of Neptune is so dainty,

that it was first thought
to be the fragments of a ring.

Not a ring, but
a collection of arcs.

That was, until NASA's
Voyager 2 spacecraft revealed

that the so-called
arcs were clumps,

the thicker parts of
a fainter, complete ring.

It's funny that the weirdest
planet in the solar system has

attracted the least attention.

Voyager 2 is the only
spacecraft that has ever been

sent on a reconnaissance
mission to Uranus,

one of the two ice giant
planets that circle the sun.

During its 20-year-long summers,

the sun never sets on Uranus.

The winters
are equally as long,

20 years of unbroken night.

Unlike its fellow gas planets,
Uranus is cold-hearted.

It doesn't
generate any internal heat.

Uranus is one crazy world.

The outer edge of
Uranus's atmosphere is so hot,

it's hotter than
500 degrees Fahrenheit.

But Uranus also
has the coldest clouds
in the solar system,

I'm talking nearly
400 degrees below zero.

What kind of ocean is this?

Is it made of ammonia?

Water?

Some scientists think it may
be an ocean of liquid diamonds.

Note to space agencies,
might be worth another visit.

Then there's that thing
about it being sideways.

Uranus revolves around the sun
at a roughly 90 degree angle
to its own orbital plane.

What could have
happened to Uranus that
it got knocked on its ass?

Our best guess is that
it went something like this.

Uranus was in
a terrible accident.

(crashing)

(crashing)

After the second blow,
the rotational axis of
Uranus tipped 98 degrees.

There's another world in
our solar system that we don't

think of as having a ring.

The rings of Jupiter were
so dim that no ground-based

telescope ever saw them.

They were discovered when
Voyager 1 came flying by.

Our Saturn is graced
by the loveliest, largest,

and brightest ring
system of any around our sun.

It's the most distant
planet that can be seen
with the naked eye,

and it made quite an
impression on our ancestors.

When I think of the
Babylonians of 3,500
years ago looking up

at the planets and stars,

I wonder how unlikely it would
have seemed that one of their

species would actually
send an emissary to that

distant point of light.

We are in the Deep Space
Network room at NASA's
Jet Propulsion Laboratory.

In this place, the most
ambitious voyages of discovery
are directed and monitored.

Why are these
people so emotional?

They have committed
their professional lives to

a collaboration
with this robot.

And now that partnership
of decades is about to end

in a most violent way.

The pathway from our
Earthbound helplessness to

our presence in Saturn's
skies is about to unfold.

TYSON: What is that
shimmering, unsteady
thing we're looking at?

That's what Galileo Galilei
asked himself in 1610 when he

became the first human
to see Saturn as more than

just a point of light.

So, this is the telescope
that made the modern

scientific revolution possible.

You know, you
really started something.

You looked through that
thing and found the cosmos.

That's not to say you didn't
make your share of mistakes.

You guessed wrong at
what you thought you saw,

believing that Saturn
sported two symmetrical moons

on either side of it.

Two years later, when
you took a second look,

you were shocked to find
that your "moons" had vanished.

This was because both
worlds, Earth and Saturn,

were in motion,
and the two worlds had changed
in position to each other.

You were now looking at
Saturn's rings, edge-on.

The Saturn ring system
is 175,000 miles across,

but on average only
a few hundred feet thick.

They were too thin for your
fledgling telescope to see.

But two years after that,
you took a third look.

Now, you thought
that the planet had arms.

♪ ♪

40 years passed, until
a Dutch astronomer named

Christiaan Huygens took
another look at Saturn with

his own greatly
improved telescope.

Huygens was the first
to know that worlds could

be circled by rings,
and Saturn was one of them.

He also discovered
Saturn's largest moon,

which would later
be known as Titan.

When it finally came time
for us to visit that world,

our spacecraft
bore Huygens's name.

In science, there are
the Galileos, the Newtons,

the Darwins, the Einsteins.

And then there's another
kind of great scientist.

Not the kind that paints
a whole new picture of nature,

but, like Christiaan Huygens,

someone who has
much to contribute,

filling in a blank
or two on that vast canvas.

Such a scientist was
Giovanni Domenico Cassini.

He was born early
in the 17th century in
the town of Perinaldo,

in what is now Italy.

Cassini didn't
start out as a scientist.

He began his career as a
pseudo-scientist, an astrologer.

Astrology is a collection of
ideas based on the notion that

worlds have certain
human personality traits,

and that the influence
of these distant worlds,

depending on which are
rising and falling at the time

of your birth, will
determine who you are and

what your fate will be.

It's another
form of prejudice,

making unfounded
assumptions about who a person

is without bothering
to get to know them.

Astronomy and astrology
used to be the same thing,

until there was
a great awakening to our

actual circumstances
in the cosmos.

In 1543,
Nicolaus Copernicus,

a Polish cleric
demonstrated that,

contrary to
popular belief,

we were not the
center of the universe...

the Earth and the
other planets travelled
around the sun.

Demoting the Earth from
the center of the universe

was a severe blow
to human self-esteem.

More than a century later,

some people still
hadn't gotten over it,

and Giovanni Cassini
was one of them.

Cassini accepted
a terrific job offer,

an appointment
by Louis the XIV,

the legendary
sun King of France,

Louis believed himself to
be an absolute ruler whose
dominion was God's will.

But he was also the first
monarch in Europe to recognize

the great power of science.

He knew it was vital
to national security.

Louis the XIV was
inventing the first modern,

governmental, scientific
research institute,

The Paris Observatory.

Cassini told the absolute
ruler that he would not be

staying long in Paris,
a year or two, at most.

But when the King
placed his new observatory
at Cassini's disposal,

he lost all interest
in returning home
to Italy ever again.

For the next 125 years,

the Paris Observatory
would be led by a Cassini.

Cassini rewarded his
patron with a map of the Moon

that remained
cutting-edge for a century.

King Louis financed a research
expedition to South America

to obtain more accurate
measurements of longitude,

intel of enormous value to
the captains of his far-flung

fleet and to astronomers.

Cassini took all these data
and became the first person

to calculate the scale
of the Copernican solar system

that he had once rejected.

With his increasingly
powerful telescopes,

he discovered the
length of a day on Jupiter

and the bands and spots
on that planet's surface.

Cassini discovered
Jupiter's Great
Red Spot independently

of Robert Hooke in
England, and to this day,

they share the credit.

Cassini went on to determine
the length of the day on Mars.

He was only off
by three minutes.

When he returned to his
observations of Jupiter,

he was stumped by the
contradictions in them.

The eclipses by Jupiter's
moons did not begin when
they were supposed to,

they varied from
observation to observation.

Could it be that it was
due to changes in the distance

of the Earth from Jupiter,
as the two worlds moved
through the solar system?

If that were true, then
light could not travel at

an infinite speed
because it was taking
longer to reach Earth.

Was the speed of light finite?

This idea was just
too crazy for Cassini,
too revolutionary.

He rejected it out of hand.

If he had followed the
evidence wherever it led,

he would have given us the
yardstick for the cosmos that

we still use 350 years later.

But Cassini,
ever the conservative,

dismissed the idea
as being just too wacky.

Several years later,
a Danish astronomer,

Ole Romer, became
Cassini's assistant
at the Paris Observatory.

Romer made his own
observations of the eclipses

of some of Jupiter's moons
and found the same discrepancies

in the data that
Cassini had dismissed.

But Romer recognized
them for what they were,

Pieces of evidence for
the finite speed of light.

There was a time, however,
when Cassini's faithfulness

to the data was so extreme,
that he was willing to risk the

displeasure of King Louis.

The monarch asked
Cassini to calculate the
exact area of his realm.

No one had ever attempted
to make an accurate map,

much less a topographical
one that would feature all

the mountains and rivers
and valleys of France,

or of any other
country for that matter.

Cassini rose to the task,
but discovered results that

could not possibly
please the King.

(sighs)

Cassini told the King,

"I have some rather
disappointing news
for you, Your Highness.

We all thought that France
was a whole lot bigger
than our studies, revealed.

I'm afraid, Your Majesty,
your kingdom is much smaller
than heretofore thought."

(grunts)

(gasps)

TYSON: The King
surprised everyone with
his great good humor,

saying, "Why, Cassini,
you've robbed me of more land

than all the armies of
my enemies combined."

(laughing)

TYSON: And then, there
is his work on Saturn.

He was the first
person to know what the
rings of Saturn really were.

He proposed that
they were not solid,

but instead composed of
countless satellites orbiting

the planet, and he
observed that there was

a division
between the rings.

Cassini filled in some
of the big blanks in our
understanding of Saturn,

but how could we
possibly ever get there?

Accomplishing that mythic
quest was left to one whose

tragic life would have
been completely forgotten,

if not for what
you are about to see.

TYSON: Weighing in at more
than 12,000 pounds at launch,

NASA's Cassini
spacecraft is the size of a bus.

That figure included 70 pounds
of plutonium 238 fuel,

enough to last her
for more than 20 years.

But that's not what
powered her mythic odyssey.

She rode gravity's
rainbow all the way
to the outer-solar system.

The lineage of the greatest
of human achievements stretches

further back
than we might assume.

Some of their roots
are buried deep inside
the tomb of lost hope.

But somehow, dreams rise.

The epic missions of the first
golden age of space exploration,

and likely the next,

were made possible
by a man whose two names,

one real, one fake,
are equally forgotten.

(knocking)

(grunts)

(knocking)

Alexander Shargei's early
years are not well-documented,

but it is believed that his
mother, a political activist,

was taken from him when
he was only five years old.

He took refuge in
his father's physics and
mathematics textbooks.

But by the time
Alexander was 13,

the boy had lost
his father, too.

He lived with his grandmother,
and despite great hardship,

he managed to
be accepted at the most
prestigious high school,

and afterwards
gained admission to the

best engineering
institute in the Ukraine.

But only two months after
he arrived there, in 1914,

he was drafted into
the Czar's army to fight

in the First World War.

(explosions, gunfire)

(explosions, gunfire)

In the hell of
war at the front,

Alexander Shargei
conceived a scientific strategy

for exploring the Moon,
not intended as fiction,

but as blueprint.

(engine blast)

(engine blast)

(engine blast)

But Shargei's hell
didn't end with the war.

Now, Shargei was forced
to navigate the treacherous

political mine fields
of revolutionary Russia.

He was much better at figuring
out how to get to the Moon.

Former officers in
the Czar's army and those,

such as Shargei,
who were forced to join

the counter-revolutionary
White Army,

were assumed to be
"enemies of the people."

(shouting in Russian)

TYSON: Shargei could find
no peace in the Soviet Union,

so in desperation he
tried to escape to Poland.

Shargei, weakened by
illness, was stopped by guards

and turned
back from the border.

TYSON: These were
dangerous times,

and there was no telling
what would get you
into serious trouble.

No one knows where Shargei
spent the next three years.

He simply vanished.

When at last he emerged,
Alexander Shargei was no more.

In his desperation
to be left alone,

he took the
name of a dead man.

He was now Yuri Kondratyuk.

He finally published
the book he had been dreaming

about since his
time in the trenches.

No publisher was interested,

so he printed it
at his own expense.

It was Kondratyuk's
letter to a future
no one else could see.

He wrote it "To Whoever Will
Read This Paper in Order to

Build an Interplanetary Rocket."

In the late 1920s,

Kondratyuk was enlisted
to design a grain elevator.

The Soviet Union was
going through a metal shortage,

so Kondratyuk's challenge
was to build the largest grain

elevator possible without
using more than a single nail.

It ended up being so big,
they named it "the Mastodon."

Such was the nightmare
logic of Stalin's Soviet Union.

You could do the heroic
in service to the state,

successfully execute the
seemingly impossible order

to build a colossus
with but a single nail.

And when it was done,

you could be
imprisoned for sabotage.

Who but an enemy of the state
would do such a reckless thing

as building a
colossal grain elevator
with only a single nail.

It made no difference to
Kondratyuk's fate that the

grain elevator functioned
for another 60 years,

until it burned down.

Kondratyuk was
sentenced to three years
in a special prison camp,

something new,
called a sharashka,

where scientists and engineers
slaved away on the nation's
most ambitious projects.

Kondratyuk threw himself
into a wind power project,

but still he dreamed of
exploring the solar system.

Soon after that,
he met Sergei Korolev,

who also dreamed of leaving
Earth to explore the cosmos.

Korolev would later
become the father of the
Soviet rocket program.

Korolev wanted to enlist
Kondratyuk in his fledgling

rocket program, but
Kondratyuk was so terrified

that any change in
his status might result
in closer scrutiny by

the secret police,
he declined.

If the authorities
discovered that Kondratyuk
was really Shargei,

there was no telling
what they would do to him.

When Germany attacked Russia,

Kondratyuk volunteered for
armed service at the front,

where he led a
communications outfit.

His precise fate is unknown,
but he is believed to have

died in battle on a
February night in 1942.

Alexander Shargei, aka
Yuri Kondratyuk, was only 44.

That was the
end of his story,

but not his dream.

In the early days
of the Apollo program,

the scientists and engineers
struggled to figure out how

a rocket could leave the Earth
and land directly on the Moon.

They were stymied.

They couldn't figure it out.

You need a big powerful
rocket to reach the Moon.

How could you land such
a thing on the surface

of another world
without crashing it?

Being able to guarantee that
it could take off again and

bring your crew safely home,
was even more of a longshot.

This approach, known
as "Direct Ascent,"

seemed like a dead-end
to a NASA engineer named
John Houbolt and his colleagues.

One version of the story goes,
two space scientists had kept

the spark of
Kondratyuk's dream alive.

They delivered his 40
year-old manuscript to Houbolt.

KONDRATYUK: First of all,
to the question of the work,

let it not frighten you...

Speaking about the possibility
of flight implementation,

just only remember that there
is nothing improbable on the

theoretical side of the flight
of a rocket into space...

MAN (over radio): One, zero.

(engine blast)

(engine blast)

ASTRONAUT (over radio):
37 degrees.

MAN (over radio): It's still
looking very good.

You're go.

ASTRONAUT (over radio):
We got an alarm. Bravo One.

MAN 2 (over radio): Bravo One.
Rocket 1201 alarm.

MAN (over radio): 1201 alarm.

MAN 3 (over radio):
Standby for go, Flight.

MAN (over radio):
Okay, we're go.

MAN 2 (over radio): We're go.
Sync tight. We're go.

MAN 3 (over radio):
Altitude 1600.

MAN 2 (over radio):
Eagle looking great.

ASTRONAUT (over radio):
Tranquility base here.

The eagle has landed.

The surface appears
to be very fine grained

as you get close to it.

It's almost like a powder.

TYSON: NASA picked up
Kondratyuk's vision of a

Lunar Orbiter Rendezvous and
took it all the way to the Moon.

But Kondratyuk's
horizon extended far beyond.

Kondratyuk envisioned
the first reconnaissance of

the solar system by
swinging round the planets,

and using the force
of their gravity to slingshot

the craft farther
out into space.

He dreamt that we would
swing from world to world as

our ancestors had done
from tree to tree,

bending gravity to human needs
on a slightly grander scale.

But what gravity giveth,
it can also taketh away.

TYSON: Why do some worlds
have rings, and others don't?

Why no rings for Earth?

Or Mars?

We wouldn't recognize
Saturn without them.

He looks naked
without his rings,

but how did he get
them in the first place?

This is exactly what
the French astronomer
Édouard Roche asked

himself when he
looked at Saturn through
his telescope in 1848.

Roche speculated
that Saturn's rings
were the debris of a moon,

or moons, that
had ventured too close,

and were pulled apart
by the massive planet.

♪ ♪

Roche was able to
devise an equation that
applies to all worlds.

It tells you how closely
a body can come to a planet

before it's pulled
apart by the planet's
tidal forces of gravity,

and is turned into a ring.

That's the Roche limit.

But until NASA's Cassini
spacecraft executed a series

of daredevil maneuvers
in the Saturn system,

there was a vigorous
scientific debate about

when his rings formed.

Some astronomers
suggested they were nearly

as old as the planet itself.

More than 4 billion years ago,
when the planet coalesced out

of the disc of gas and dust
that surrounded the newborn sun,

a moon, or moons, likely
violated Saturn's Roche limit...

Others thought the
rings to be fairly recent.

Perhaps, only 100
million years old or so.

And the Cassini spacecraft
proved them right.

What is Earth's
own Roche limit?

If the Moon were ever to come
closer than 12,000 miles,

which, by the way,
it's absolutely in no
danger of doing.

And it's a good thing, too,

because I like our
Moon right where it is.

There's only one other moon
in the solar system that moves

me like ours does.

Maybe it's because it's
the only one with a thick

atmosphere like Earth's, and
the kind of surface features,

lakes and mountains,
that remind me of home.

All of this was hidden
from view by a dense layer

of orange smog, until
the European Space Agency

collaborated with NASA
to send a spacecraft to land

on his mysterious surface.

Yes, that would be
the one named after you,

Christiaan Huygens,
first to see that world
through your telescope.

After an interplanetary
voyage of seven years,

the Cassini-Huygens spacecraft
arrived in the Saturn system,

the fourth of our
ships to venture there.

But the first to send a
probe to explore the surface
of Saturn's moon, Titan

and to reveal a moon of far
greater complexity and splendor

than our own rather
dull and lifeless Moon.

As Carl Sagan had predicted
more than two decades before,

there were seas of
methane, and ethane,

and there was water-ice.

When Cassini first
arrived in 2004 at Saturn's

northern hemisphere, it
was in the depths of winter.

And the Sun didn't come
out until five years later,

when Saturn's
northern spring began.

Is it just me, or is this
whirling hexagon at Saturn's

North Pole every bit as exotic
as the fantasies our ancient

ancestors had of these worlds?

The geometrically regular
hexagonal shape of this

feature brings to mind the
handiwork of intelligence,

terraforming,
re-working the surface
for some unknown purpose.

But it's actually the result
of the sudden change in wind

speeds as vast upwellings
of ammonia rise near the poles.

It's the mother
of all hurricanes,

a frenzy of thunder
and lightning,

containing countless
hurricanes within it.

Spring can be a violent,
stormy season, on Earth, too.

But it was during Saturn's
seven year-long summer that

Cassini was commanded
to take her own life.

♪ ♪

TYSON: There's a human conceit
that at the moment of death,

we re-live our
greatest memories.

You are riffling through the
memory bank of a doomed robot,

about to carry out
the cruelest command.

♪ ♪

♪ ♪

♪ ♪

♪ ♪

♪ ♪

The mission planners at
NASA's Jet Propulsion Laboratory

call this the "ball of yarn,"

13 years of exploration
through the Saturn system.

From the time
of her launch in 1997 and
throughout her epic voyage,

she has used the gravity
assist conceived 100 years
before by Yuri Kondratyuk.

But it was her supply of
rocket fuel that made it

possible for her Earthbound
controllers to steer her into

new trajectories
of exploration.

In April of 2017, Cassini
was running low on that fuel.

It was time for her most
daring maneuvers of all,

before she was to be
sent into a final death dive.

These are the mission
scientists of Cassini,

some of whom have been
working on the project since

the 1990s, when it
was no more than a dream.

They know that
Cassini must die.

It's too dangerous to
let her wander aimlessly.

She might crash into one of
the moons in the Saturn system

where life might be hiding.

This would violate
NASA's planetary protection

conventions on quarantine
in the book of space laws.

If left to chance,
Cassini could alter the

possible biological destiny
of Titan or Enceladus.

A terrible command
must now be given.

Cassini is so far away,
it will take the message,

traveling at
the speed of light,

more than an
hour to reach her.

Every microchip in her
has been programmed to resist

the commands
she's now receiving.

The inner-turmoil of the
loyal robot commanded to defy

her own instincts
must be fierce.

The same engineers who
ordered her to protect herself

in every situation now force
her to plunge to her death.

They must be obeyed.

MAN (over radio):
System lead ace.

We have telemetry
AOS at zero one.

One, niner.
One two.

TYSON: She fights off the
immense forces by struggling

to right herself
one last time.

She fires her
thrusters at 100%,

all the while faithfully
sending back more data than

her designers
ever hoped she would.

WOMAN (over radio): Project
Manager. Flight Director.

MAN (over radio): Go ahead.

WOMAN (over radio): Okay. We'd
call loss of signal at 11:55:4.

TYSON: She fights the brutal
atmospheric resistance until

her fuel tanks are empty,

and there's no
more fight left in her.

MAN (over radio): Project
manager on, maybe a trickle
of telemetry left, but,

just heard the signal
from the spacecraft is gone

and within the next 45 seconds
so will be the spacecraft.

♪ ♪

TYSON: Official time of
death: 11:55 universal time.

There are all kinds of
stories in the struggle
to understand the cosmos.

Sometimes your
dreams die with you,

but sometimes the scientists
of another age pick them up,

and take them to the
Moon, and far beyond.

The name of Yuri
Kondratyuk was forgotten,

but there was
one who remembered.

When Neil Armstrong returned
from his trip to the Moon,

he made a pilgrimage to
the childhood home of the man

who made his
mythic voyage possible.

♪ ♪

Captioned by
Cotter Captioning Services.