Space's Deepest Secrets

We got a booming carrier... Everything looks great.

A billion miles from home...

Ansco systems, Cassini Ace...

Running low on fuel... We have a good lock.

Almost out of time.

We're putting down a fully functioning spacecraft.

After 13 years orbiting Saturn,

the spacecraft Cassini

is about to plunge to a fiery death,

becoming part of the very planet it has been exploring.

Cassini was not so much of a mission as a way of life.

I've spent 20 years of my life on this.

What we found was spectacular.

Cassini sent back dramatic visions of strange new worlds.

Nothing of what we had imagined came close to the reality.

It revealed methane lakes, electric dunes, varied oceans.

That moon has an ocean in it that could harbor life.

It's the end of a mission that has not only unveiled the beauty

and probed the mysteries of Saturn,

but has changed our view of the solar system forever.

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Systems lead, mission planning.

Go ahead, mission planning.

The spacecraft has just crossed 30 degrees north latitude.

Altitude is 6,000 miles.

The dead of night, Friday the 15th of September

in the control room

of NASA's jet propulsion laboratory...

The flight director and her team of engineers

are presiding over the death of a spacecraft

that they have nurtured for nearly three decades.

Ansco systems, Cassini's station...

In less than an hour, they will watch as Cassini

sends its final transmission.

- Copy. - It's sad.

It was 27 years of the investment

of many lives into this.

Nearby, at the California institute of technology,

is the vast family of scientists from around the world

who run the 12 instruments on Cassini,

measuring everything from infrared to radar,

magnetic fields, and cosmic dust.

In some ways, I just want it to be over now...

You know, you're sort of waiting for it to end, and...

And it's really weird.

Very mixed emotions at the moment... really strange.

All have played a vital role in exploring Saturn.

But it's Cassini's skills with a camera

that have been truly inspirational.

Head of the camera team

and guardian of the Cassini image gallery

is Carolyn Porco.

Carolyn has been responsible for designing the camera systems,

deciding when, where, and which pictures to take,

and delivering and processing

hundreds of thousands of images of Saturn...

Its rings and moons.

This is one of my favorites.

The reason why I love it

is because we're seeing the rings edge on,

and you just really can tell how thin they are.

You can get the sense of three dimensionality.

And this is the famous hexagon, okay?

This is the feature that drives everybody crazy

because they don't expect to see something

that is straight-sided in an atmosphere.

It is nothing more than a jet stream like our jet stream.

Okay, really. You can relax.

This is not the end of the world.

Back at the rings... I mean, have you ever,

ever seen anything

just so magnificently regular and beautiful?

With its two on-board cameras,

Cassini has unveiled the Saturn system

as a strange, mysterious, and unique place.

Saturn just captivates people

because it looks so supernatural.

It engenders the immediate feeling

that it can't possibly be real.

But we're lucky to have it.

I think we're damn lucky to have Saturn.

I glad I grew up in a solar system

that had a planet like Saturn.

But taking and downloading such amazing pictures on your camera

that's a billion miles away through the bleak void

of outer space is no easy feat.

In charge of remotely managing this spacecraft

from NASA's jet propulsion laboratory is Julie Webster.

You know, scientists and engineers are true nerds.

So you'll see a lot of nerds stuff on the

Julie is Cassini's chief engineer.

She's been caring for the intrepid explorer

since before it left home,

and uses a scale model of the spacecraft

to demonstrate its capabilities.

This is a quarter-size model, so this is a quarter-size me.

I'd like to be this weight, not this height.

So you start at the top.

This is a four-meter antenna.

It was also designed for radar.

So this is the composite infrared spectrophotometer.

This is the ultraviolet spectrophotometer.

This is the VIMs, visual and infrared.

And these are the imaging cameras,

the narrow angle and wide angle

that are used for the actual photos that you see.

So this is the ion and neutral mass spectrometer

that is the most important data

that we're gonna get in the last few hours.

And here's part of the magnetometer instrument,

and here's the other half of the magnetometer instrument.

The... trick is... The reason you want

to put it out on a boom, is you do not want to measure

the magnetic field of the spacecraft.

You want to measure the magnetic field of Saturn

or whatever you're at the time.

Let's see... That's the nuclear battery.

I actually sat inside this part during the build,

so when I close my eyes and think of Cassini,

I actually see the wiring inside the spacecraft,

and the things switching on and off,

and when it goes in that's...

That's what I'm going to see in my mind, is the...

Is the aluminum melting on the structure.

So now we're headed back up to the first floor to my office.

Cassini divides its time between gathering data,

which it stores on its internal memory,

and then sending it back home.

A typical day we're out taking pictures, collecting data,

storing it on the solid state recorder,

and then we'll turn back to earth,

and we'll play it back for nine hours.

We only have four gigabits of data that we can load up,

and it takes nine-plus hours to play that data back.

For nine hours at a time up to six times a week,

Cassini sends its precious images of Saturn

on the billion-mile journey back to earth.

We have cleared the tower,

and the Cassini spacecraft is on its way to Saturn.

So what does it take to get a spacecraft the size of a bus

with 12 delicate instruments all the way to Saturn

and to keep it operating for 20 years?

And the solid rocket boosters have been...

In the mission to get closer to Saturn than ever before,

getting the Cassini spacecraft to its new home

was a challenge for the team of fearless rocket scientists.

So, we'll go into the dark room.

Inside the dark room, the mission-support area

is where the whole flight team gathers for critical events,

like the final plunge, launch, or orbit insertion.

It took seven years to get to Saturn,

a spiraling journey that involved four gravity assists,

close flybys past planets

that boost the speed like a slingshot.

It's a flight plan designed by head of navigation, Duane Roth.

- We had a Titan iv-b launch? - Titan iv-b.

So that... that was to get us away from the... the earth,

but then it still wasn't quite enough

to make it all the way to Saturn,

so we had two Venus flybys,

gravity assists from each of those, an earth gravity assist,

and finally we've got a Jupiter gravity assist,

and that got us to Saturn.

Once Cassini was approaching Saturn, it had to perform

possibly it's most critical maneuver of the mission...

A perfectly timed engine burn that would slow it down enough

to be captured in orbit by the giant planet.

Saturn orbit insertion was, obviously,

incredibly nerve-wracking.

We spent seven years guiding this spacecraft

to get to Saturn, to get it into orbit.

If it hadn't done the orbit insertion,

which was a 90-minute burn on the main engine...

If we hadn't done that, we'd have been a Saturn flyby

and just gone on out in space.

The Doppler has flattened up.

During its 13-year stay, Cassini has revealed Saturn

as a unique Jewel in the solar system...

A gas giant with swirling storms,

a dancing sprinkling of moons,

and surrounded by bright but paper-thin rings of ice.

The origin of the rings is still a mystery,

as is the complex gravitational interplay

between rings, moons, and planet.

So, this is one of those discoveries we made

that really threw us for a loop.

This is the outer edge of the "B" ring,

and these, as you can see,

are spiky shadows that are created by these features here

that are sticking out two-and-a-half miles,

two-and-a-half miles above a sheet of debris

that's only 30-feet thick.

It was just extraordinary.

It was out of science fiction.

That's what this whole mission has been.

But hidden in the images from Cassini

are clues to the formation of this complex and dynamic system.

Well, we know the rings of Saturn are...

Are made of ice,

and this is a really solid block of ice here.