NOVA

A daring mission

to reveal secrets of our solar system's distant past...

Asteroids are actually tracers of our history.

And help safeguard our future.

Asteroids might strike the planet.

The damage created by that would be absolutely enormous.

Can this spacecraft unlock this asteroid's secrets

by grabbing a piece

and bringing it back to Earth?

This has really proven to be difficult.

We literally expected this asteroid to look like a beach.

That is not what it looked like at all.

It's just rocks everywhere.

Oh, my gosh, those big boulders

were just not what we were expecting to find.

When we go to see an asteroid,

all our assumptions are usually totally...

Messed up.

There's a million things that could go wrong

and the show could be over at that point.

"Touching the Asteroid,"

right now, on "NOVA."

We spent years preparing for this,

analyzing every scenario.

It's very nerve-racking.

This is an object we've never been to,

something that's never been done before.

We're really pushing the envelope of what

the spacecraft and the team can do.

I'm very excited and also very nervous.

You've gotta persist at it,

you gotta know what you're doing,

and sometimes you just have to be lucky.

More than 200 million miles from Earth,

a spacecraft named Osiris Rex approaches an asteroid.

In Littleton, Colorado,

a team of space explorers nervously waits,

hoping their spacecraft can do something extraordinary...

grab a piece of an asteroid named Bennu.

Osiris Rex is going to be

the largest sample collection robotically in the history

of solar system exploration.

If all is working as planned,

the robotic explorer is reaching for the surface,

grabbing as much rock, dirt, and dust

as it possibly can.

Just five seconds later, it will retreat.

Osiris Rex must complete this critical task

totally on its own,

with no human at the controls.

We won't know what has happened

until we get away from the asteroid surface.

This is a really nail-biting moment.

Once the spacecraft safely leaves the surface,

it will store its precious cargo and bring it back to Earth.

Even a small handful of asteroid dust could answer big questions.

It's really amazing that these

tiny specks of dust grains can tell you so much

about how our universe formed,

how our solar system formed,

how asteroids like Bennu formed, and how Earth formed.

They could even provide clues to how life emerged on our planet.

There is truth out there,

there is an objective reality,

and all you need to do is go out and find it.

Other missions have gone in search of that truth before,

attempting to grab bits and pieces of distant space rocks.

Back in 2004, the Stardust spacecraft

flew through the tail of a comet.

It had a tennis racket type of a collector,

is the best way to describe it.

It was a grid,

and it was able to put that grid out as it flew

through the comet tail,

and collect those particles,

stow it into its sample return capsule, and return it to Earth.

While it was an arduous task

to find the microscopic particles

trapped inside the grid,

researchers made profound discoveries

that have revolutionized our understanding

of solar system formation

with about one milligram of space dust.

In 2005, the Japanese space exploration agency's

Hayabusa mission attempted to grab a piece of an asteroid

named Itokawa.

The mission was filled with mishaps.

There were a lot of troubles.

We had a lot of discouragement or disappointment.

Hayabusa was like Apollo 13.

It was a, it was a successful failure.

I mean, they had so many things go wrong,

yet they still managed to get the spacecraft back to Earth.

It was a first...

Bits and pieces of asteroid dust and dirt

were brought back to Earth.

But their take was small...

only about 1,500 tiny grains of Itokawa.

The Hayabusa samples were specifically grains

that are between 20 and 100 microns in size.

So just to give you an estimate

of how small that is,

diameter of human hair

is between 100 to 200 microns in size.

And so, we're looking at particles that are

half the diameter or smaller.

The amount of asteroid dust Osiris Rex could scoop up

is enough to fill a few grande size coffee cups.

If we were able to collect

that much material, it would be orders of magnitude larger

than any other sampling ever done

at any asteroid anywhere, ever.

In fact, it would be thousands of times more,

and could reveal mountains of solar system secrets.

Ten seconds, nine, eight, seven...

September 8, 2016.

Three, two, one, and lift-off of Osiris Rex,

its seven-year mission to boldly go

to the asteroid Bennu and back.

There is nothing quite like launch.

The power of a rocket is immense,

and even if you're several miles away from it,

you really feel that, you know, in your body.

The only way I can describe the experience

is transcendental,

because your whole career has led up to that moment,

and there's a million things

that go through your mind that could go wrong,

and the show could be over at that point.

So, you kind of just have to

reach that peaceful moment

inside yourself and enjoy it, experience it,

and whatever is going to happen is going to happen.

Osiris Rex has gone supersonic.

As an Atlas V rocket hurls the spacecraft out of Earth's orbit,

the people behind the mission

trust that math and gravity

will guide it across millions of miles

to its tiny target.

The first several months of the mission

went very smoothly,

the spacecraft was slowly approaching Bennu.

The next step now is all eyes on the prize,

focused on collecting the sample and bringing it back to Earth.

Why are we going to Bennu?

What makes this asteroid so intriguing?

One of the first jobs I had on this mission

was actually to find an asteroid

that we can go to.

And you would think that would be easy.

I mean, like, nowadays,

there is almost a million asteroids that we know about.

Like Vesta, pockmarked with craters.

Potato-shaped Ida has its own moon.

Chariklo is the smallest known celestial object with rings.

But scientists have had their eye on Bennu for over 20 years.

From Earth,

Bennu is a barely discernible dot of light,

even from Earth telescopes on mountaintops,

you really can't get a good picture of Bennu.

Why, then, is this mysterious dot in the night sky

one in a million?

1999.

The Arecibo radio telescope and the Goldstone Deep Space network

took this series of radar images of Bennu.

Although grainy and pixelated,

they start to paint a picture of this tiny asteroid.

We were able to

map its shape and its rotation, and really get

a pretty good idea what size it was going to be

and what the overall structure of the asteroid

was going to look like.

Bennu is shaped like a spinning top.

It completes a full rotation

about every four-and-a-half hours.

When it comes to its size,

this space rock isn't much taller

than the Empire State Building.

But it's Bennu's location that really piques

the team's interest.

Typically, when we think about

where asteroids exist in our solar system,

we think about the asteroid belt,

which is a region in space

between the orbits of Mars and Jupiter.

But there are a whole class of asteroids like Bennu

that we identify as near-Earth asteroids,

because their trajectory brings them close to Earth

at some point.

There are more than 20,000 near-Earth asteroids.

The closer an asteroid is to Earth, the easier it is

to reach with a spacecraft.

You're limited by the rocket you can use,

you're limited by how long the mission can be,

because, you know, time is money.

So if you want to go to easy- to-get-to, accessible objects,

they have to be really close to the Earth.

Of course, if an asteroid is in our neighborhood

and easy to get to, that can also mean it's easy

for the asteroid to get to us.