All language subtitles for NOVA.S47E14.Touching.the.Asteroid.1080p.AMZN.WEB-DL.DDP.2.0.H.264-GNOME_track3_[eng]

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.

65 million years ago,

an enormous asteroid

crashed into the Earth...

creating an enormous
cloud of dust and dirt

that blocked out sunlight
all across the planet.

Vegetation could no longer
grow in adequate quantities

to keep the herbivores

of the planet alive.

So there was an
enormous extinction event

that took place.

We mark that period of time as
the end of the era of dinosaurs.

This asteroid did

a lot of damage from which,
you know, modern-day society

would not survive.

There is a real threat.

We know that.

I mean, we, we can see

the scars on the planet.

The planet has been hit
before; it will be hit again.

Researchers predict
that as early as 2175,

Bennu's orbit could be on
a collision course with Earth.

Should that happen,

the damage created by that
would be absolutely enormous.

The energy that it would
release would be equal to

1,200 megatons of force.

That's larger than all of
the nuclear explosions

since World War II.

It is not going to end

life on the planet.

That, that is not
going to happen.

But it does have enough
energy to wipe out a city.

If it hits on a populated
area, that city will be gone.

We need to take this seriously.

The chance of an impact is low,

but the consequences
are very high.

A deeper understanding
of near-Earth asteroids

could help future scientists

design a mission to deflect or
disrupt these potential killers,

but they can also help reveal

secrets of the
Earth's distant past.

Asteroids actually are remnants

left over from the earliest
periods in the history

of our solar system.

They essentially have locked up
inside them many of the secrets

of what the solar system
was like when it first began.

4.5 billion years ago,

as the planets in our
solar system formed,

gas and dust stuck
together, forming pebbles.

These are like the earliest
formed solids that you can find.

Pebbles grew into boulders.

Of course, in all this mess,

there's lots of
collisions going on.

Boulders into
mountain-sized asteroids.

You have all these
asteroids hitting each other.

You have proto-planets that are

being hit by these asteroids.

It's chaotic.

When the dust settled, the
planets had taken shape.

But there was plenty
of material left over...

millions of small chunks
of rock, metal, and ice.

These asteroids are
actually tracers of our history.

So if you take a planet,
a planet is like an omelet.

A complex mix of ingredients
assembled bit by bit.

You start with the
two yellow eggs...

Perhaps a pepper, an onion...

Salt...

and possibly cheese.

You put them in a pan,

it warms up,

and then it's transformed
into an omelet.

So if I show you an omelet,
and you never saw eggs before,

you would never be able

to deduce that you
started with eggs.

Just like an omelet,
planet Earth's ingredients

have been scrambled
and cooked over time.

Earth has been changing.

You have volcanoes.

You have earthquakes.

And it's difficult to know
exactly what Earth was like

at the very beginning
of the formation.

Asteroids like Bennu, on
the other hand, are remnants

of that very, very earliest
part of solar system history,

so they're little time
capsules that record

what kinds of
chemistry was present.

And they may contain some
of the same key ingredients

in Earth's original recipe,

including one very
special ingredient

that none of us
could live without.

We knew Bennu was very dark,

and that was one of the
prime reasons that we picked it.

We think that means that it
has a lot of carbon on its surface,

and particularly in
organic molecules.

Carbon forms the
backbone of all life on Earth.

It's in land, air,
and the ocean.

And in every plant and animal.

But how did it all get here?

It would be much easier if
we could just say that carbon

was right here to begin
with, but if we actually look

at the very earliest history
of the development of Earth,

the first 600 million years,
this planet is entirely molten.

It's a cauldron of
lava and magma.

With surface temperatures
estimated at at least

3,600 degrees Fahrenheit,

any carbon near Earth's
molten surface would have

evaporated into space.

So we still have this mystery
on our hands: how did carbon

get to this planet?

Did this key ingredient for life

actually hitch a ride to Earth
on comets and asteroids?

One of the idea

is that this impact brought
all the element that favor

the emergence of life on Earth.

In 2014, one
extraordinary mission

of the European Space Agency,

named Rosetta, found
some important clues.

The intention of Rosetta

was to land onto the surface of

Comet 67P, so that
we could better study

what the surface
composition was like.

The mission made history when it
dispatched a lander named Philae

onto the surface of Comet 67P,

the first landing of its kind.

We have done something
nobody had ever done.

This is an achievement not
only for ESA, but for mankind.

But the mission also
made a landmark discovery:

carbon molecules
that are crucial

for building life on Earth.

The Osiris Rex team hopes
Bennu's surface will offer

new carbon clues, and
help solve the mystery

of how Earth got its carbon.

That is, if they manage
to grab a piece of it.

The asteroid is an unknown.

You don't know when you get
there, or when you're planning

the mission, that this is going
to be a sampleable place.

Observations made by
the Spitzer Space Telescope

provided clues to
answer this question.

Spitzer's cameras see infrared,

a form of light
that signals heat.

In space, infrared instruments
can pick out objects too dim

or difficult to see,

like a distant galaxy

or a tiny asteroid.

Spitzer was able to see
how Bennu warms up

when bathed in sunlight,
as seen here in red.

It also revealed that when
the asteroid's surface rotates

out of the sun, it quickly
cools, appearing green and blue.

If you imagine being at
the beach, during the day,

the sand grains,
they're very, very small.

They absorb heat
very, very quickly.

At night, those little sand
grains cool off very quickly.

The sand is nice and cool.

Some materials cool more slowly.

Rocks that sit in the sun
all day hold on to their heat

for a longer time.

Based on the
speed of its cooling,

Bennu appeared to
behave more like sand.

Bennu was heating up
and cooling off very quickly.

We literally expected this
asteroid to look like a beach.

The kind of soft, smooth surface

even a toddler could
scoop up with ease.

Our interpretation

of the data at the time
suggested that it had

a fairly benign surface.

With evidence of Bennu's
smooth surface, rich in carbon,

along with its nearby location,

it seemed like an ideal choice.

So that's why we
ended up going there.

It really came from
a million to Bennu.

August 2018, two
years after launch

and a million miles still to go,

Osiris Rex takes its
first onboard image.

Bennu was still

just a point source...
it was unresolved.

It looked like a
star, essentially,

in our optical
navigation photographs.

Even as they get closer, Bennu's
true nature remains hidden.

The fact that we were
going so close to Bennu

and still knew so little
about its properties,

made it really
exciting and amazing.

It's a little bit tricky.

Not all the information
that you need is available.

So you can't evaluate,
in some sense, the risk.

December 3, 2018.

Osiris Rex finally
reaches its destination.

We have arrived.

It's a great accomplishment,

and now, with the
spacecraft just 12 miles

from Bennu's surface,
the team gets ready

to gaze upon the first
close-up images of the asteroid,

excited to see a smooth
and sandy surface.

I told the team

we should be
expecting a large beach,

and so, it's going to
be easy to find a place

to collect the sample.

That is not what
Bennu looked like at all.

It really blew our minds when
the data started coming in.

It's just rocks everywhere.

Oh, my gosh,

those big boulders

were just not what we
were expecting to find.

When we got the first
images of asteroid Bennu...

I was a little concerned,

a little worried, because
the surface is very rough,

very rugged.

Osiris Rex team member

Dani DellaGiustina knows a
thing or two about rugged terrain.

She spends her weekends
about an hour outside

of Tucson, Arizona,

rock climbing,

and the rest of her
days... and nights...

as the lead scientist

on the Osiris Rex
image-processing team.

Her job: to create a detailed
map of Bennu's rocky surface.

- I - think a big
part of our role

on the mission
is, is to not just be

the people that are
processing the images,

but that also help
guide their interpretation.

Bennu is remarkably deceptive.

Shadows cast by the
sun alter its appearance.

These two images were
taken of the same location

on the asteroid.

The only difference?

The time of day they were taken.

And when it comes to
finding a nice, flat spot

to grab a sample...

The orientation of the surface
is kind of all over the place.

Some of it is angled this way,

and then an adjacent
patch of surface

might be angled that way.

And as you can imagine,
that creates a lot of difficulty

when we're trying to find
a smooth patch of ground

on the surface of the asteroid.

Sometimes it's really
easy to see something

in one of the images that
we've taken of the surface

of the asteroid

that I might relate back
to an experience I've had

rock climbing.

And then I have to check myself,
and remember that rock climbing

might give me
some false intuition

about what I'm seeing on Bennu.

We're looking at a
surface of a planetary object

that is completely
distinct from Earth.

One of those differences:

the strength of Bennu's
gravity in comparison to Earth's.

Earth is trillions of times
more massive than Bennu.

Its strong gravity

creates enough pressure and
heat inside the Earth to melt rock,

and ultimately,

cook up the solid stone
Dani can safely scale.

But Bennu lacks that
gravitational power.

Bennu is such a
small object that gravity

is extremely small...
it's microgravity.

Which is just what
it sounds like...

very, very, very small
amount of gravity.

So you're not necessarily
going to compact or compress

these kinds of materials.

The boulders that make up Bennu

might be really
fluffy and porous.

So porous that if Bennu
was placed on Earth,

under the pressure
of our planet's gravity,

the boulders might
simply fall apart.

Maybe these boulders,
once we push on them...

They crumble.

But we don't know that.

So we cannot take the risk.

There's no way for the team
to know what kind of surface

they are now dealing with.

We left Earth with a spacecraft

that had a lot of capabilities
and was designed to handle,

you know, a wide
range of unknowns,

and Bennu's challenged us

to the extreme.

Sometimes things
don't go as planned.

It's not always easy...

Or straightforward.

But there's also
this incredible feeling

when you know that
you're seeing something

that nobody has
ever seen before.

It's really powerful,

and that sense of awe,

it hasn't gone away.

For most of December,
Osiris Rex spies on

the asteroid from every angle.

We began executing these
series of maneuvers to fly by closely

and estimate for the first
time what the mass of Bennu

was going to be.

And that was very important,
because until that point,

we had a really large
uncertainty in what

Bennu's actual mass was.

And we only had a few weeks
from the time that we started

doing these fly-bys,
and we determined

what we were
really dealing with,

in order for us to learn
enough about Bennu

to get into orbit safely.

New Year's Eve 2018.

Someone had the idea that
it would be fun to dress up

like we were going to
a New Year's Eve party,

'cause we're all going to
be at work on December 31.

As the rest of the world
rings in the new year,

the team faces one of
the biggest challenges

of the mission:

to guide Osiris Rex

into orbit around Bennu.

It's the first time a spacecraft

will attempt to orbit
an object this small.

We're used to flying spacecraft
in orbit around the Earth,

around Mars, around
the other large planets,

and you can predict with
a high degree of accuracy

where your spacecraft
is going to be in the future

because you understand
the gravity field so well.

It's the strong and persistent
gravity of these larger planets

that helps hold a
spacecraft in orbit.

But when you're in a
microgravity environment,

all these other forces
become significant.

One dominant force acting on
the spacecraft other than gravity

is the solar radiation
pressure, or the sunlight,

interacting with the
surface of the spacecraft.

When we talk about
radiation pressure

from the sun, we're
actually talking about

the photons of energy
that are coming from the sun

pushing on the spacecraft.

Bennu is such a small object,

this caused the
spacecraft operators

to have to do a kind of dance
between that microgravity

of the asteroid itself and
the pressure of the radiation

coming from the
sun on the spacecraft.

The navigation team
has had to model

all of these
forces to a fidelity

that's kind of unheard of
for planetary exploration.

This was the culmination
of years of work

and analysis and
planning for this moment.

Bennu became the smallest object

to ever be orbited
by a spacecraft,

and Osiris Rex became

the record holder for the
lowest orbit ever achieved

around a planetary body.

The spacecraft is now less
than a mile above the surface.

The new year seems
to be off to a great start,

but just one week later,
Bennu has another surprise

in store.

So, this is what I was doing
the morning of January 7.

While browsing through
images of the asteroid,

team member Carl Hergenrother
notices something strange.

So, I'm blinking
through the images,

blinking through the images,
blinking through the images,

and all of a
sudden, I come up to

one image in particular,

where I notice what
looks like a star cluster

right off the edge
of the asteroid,

where there shouldn't
be this many bright stars.

And these are bright.

And I'm looking at it,
and I was, like, "Well,

"that's a pretty
big star cluster.

It doesn't look like
any of the ones I know."

Hoping to get a more detailed
view of these strange stars,

Carl increases the brightness
and contrast of the images

and spots something
even more bizarre.

Wow.

These extra stars start
turning into streaks.

Tiny streaks,

like the streaks that
appear in images

taken at night on
a busy highway.

I had in the back of my
mind this little nagging feeling.

Maybe the asteroid
is doing something

that we didn't quite recognize.

He decides to investigate.

I started drawing lines
through these streaks

back to the asteroid.

It was over probably a
half-hour of time when I realized...

it didn't, like, come
immediately, at once...

that, oh, what I'm
seeing is what I'm seeing.

All these streaks kind of
coming from the same place,

which means what you're
seeing is a, kind of a,

an instantaneous event... boom.

The glowing dots no longer
look like a cluster of stars,

but bits and pieces of rock
and dust flying off Bennu.

I mean, it looks like the
asteroid just exploded.

I walked over, I grabbed Dante,

and he just turns white.

I think, literally, my jaw
hit the floor at that point.

It looks like this thing has
just turned into a comet

and is blasting particles
into outer space.

So, my first response
was, "Are we...

Is this okay for
the spacecraft?"

Immediately, we got the
spacecraft team in a room

within minutes to start
looking at this information

and saying, "Okay, do
we need to fire the engines

"and get away
from this asteroid,

or are we okay
to stay in orbit?"

They can't immediately tell
how big the particles are...

and worry that one could
be moving fast enough

to pack a damaging punch
if it hits the spacecraft.

We quickly built
up tools to analyze

how the particles were moving

by observing what the
velocities were and the sizes.

But careful analysis reveals
the particles are fairly small,

ranging in size from less
than an inch up to four inches.

And more importantly,

they are traveling at a
relatively slow speed.

The velocities were low
enough for the particles that

even if, they would essentially
bounce off the spacecraft

if they even came close.

And then the whole
mood of the team changed.

It's, like, "Okay, we
don't have to worry.

"Now this is a really
exciting scientific discovery.

"What is going on?

"Bennu is an active asteroid.

How can that possibly be?"

This may happen on every
single asteroid that's out there.

And it's just, we
were the first mission

that had the right
instrumentation,

and we're at the right distance,

and we're taking the right
data, to actually detect this,

but they all might
be doing this.

So this may be a
common phenomenon

everywhere in the solar system.

What's causing this phenomenon?

Carl has a theory.

It could be as simple
as just meteorites

hitting the surface,
constantly, you know...

The meteors you see
when you look up in the sky.

We might think that
the solar system's done.

Everything is settled in place.

But that's not the case.

The solar system is
still under construction,

so to speak.

There are still asteroids
that collide with other objects.

It isn't just, you know,
asteroids crashing

into the Earth and
killing the dinosaurs.

They're all crashing
into each other,

and they're all breaking
up and throwing off pieces.

So everything is really dynamic,
and you're just kind of watching

the solar system
evolve in real time.

Bennu has been a great puzzle.

There's been things we've seen
that we never expected to see,

such as particles being
ejected off the surface.

Some things that we thought
we would see that we haven't.

Everyone is enormously
superstitious right now.

We try not to say anything
good about the project,

because it'll jinx it, right?

I mean, this is...

a mindset that's as old
as humankind, right?

The team has no reason
to be overconfident.

As Osiris Rex circles
Bennu at close range,

taking thousands of pictures,

there's still no sign of
a safe spot to approach.

We started to become
a little bit worried,

wondering if we would actually
find a safe location to sample.

Selecting the
right site is crucial,

because it needs to
accommodate a unique device,

the first of its kind

and key to the
success of the mission.

At Lockheed Martin,
a team spent years

developing the Touch-and-Go
sample acquisition mechanism...

TAGSAM for short.

Our approach is new,
the intention to collect

a large amount
of material is new.

TAGSAM has an 11-foot-long arm

designed to reach down

and touch Bennu.

This is the only
part of the spacecraft

that's going to make contact
with the asteroid surface.

So, it's about 30
centimeters in diameter.

It looks like a really
amazing piece of technology,

but quite honestly,
it's, it's an air filter.

We put this TAGSAM device
onto the surface of the asteroid,

and then we blow down
high-pressure nitrogen gas

to kind of agitate the soil

and then basically scoop
it up in a giant air filter.

We have tested TAGSAM
hundreds of times,

and we've found that the contact
time is very dependent upon

whether or not
the surface is stiff,

like a very strong gravel bed...

in which case the
contact time will be short...

or if the material
is a little bit softer,

it allows the TAGSAM
head to sink into the surface,

potentially up to as
long as ten seconds.

After that, the spacecraft
will fire back-away thrusters

and will leave the surface.

Then our job is to figure
out what happened.

We'll actually be
able to turn it around,

and if everything goes exactly
right... it's not guaranteed...

but we may actually be able
to see right inside the TAGSAM

and see if there's anything
inside there that we collected.

But we're not relying
on that imaging data

to verify successful
sample acquisition.

We can actually
extend this way out

and we can rotate it around

360 degrees.

Think of the spacecraft
like a merry-go-round.

So if you have a merry-go-round
that is completely empty,

if you are on your own and
you're just trying to push it

so it can go faster,

you can do that quite easily.

But then just imagine
that there's another kid

that comes around, and he
wants to get on the merry-go-round.

Now you try to push it
again to make it spin,

but it is much more difficult.

The more mass on
the merry-go-round,

the more difficult
it is to push.

The same will be
true on Osiris Rex.

If there's more
mass in the collector,

then the spacecraft
will spin slower.

By measuring precisely

the change in speed
Osiris Rex spins,

the team can calculate how
much sample was collected.

We can know exactly how
much we have... absolutely.

If we discover we don't
have enough sample,

then we have two more attempts,

as we have two more gas
bottles onboard the spacecraft,

so we can go back down

for a second or a third
TAG attempt if needed.

November 2019.

Space explorers
from around the world

come together for an
international asteroid workshop.

Members of the Osiris
Rex team are there.

And so are members of Japan's
second mission to an asteroid,

Hayabusa2.

Initially, there was
a little bit of a rivalry

between the two missions.

It was, like, those guys
have the same idea

that we have.

But we very quickly realized

that we're all part
of one community.

And I think most importantly,

what we're trying
to do is really hard.

After the first
Hayabusa spacecraft

returned with its payload,

the Japanese space
exploration agency decided

to launch another,
more ambitious mission.

We were sure

we could make a
better spacecraft.

In 2018, Hayabusa2 arrived

at a new target, an asteroid

that turned out to look a
heck of a lot like Bennu.

So when we saw this shape
first, we are very surprised.

The first impression was,

"My gosh, we, we
arrive at Bennu."

What are we gonna do?

Its name is Ryugu.

When you show these
two bodies to a layman,

he would say these are twins.

Although Ryugu is about
twice the size of Bennu,

they have the same shape

and they're both carbon-rich
asteroids covered in boulders.

Why are these
asteroids so similar?

Planetary scientist Patrick
Michel, who is a member

of both the Osiris Rex
and the Hayabusa2 teams,

has a bold theory.

I proposed the theory that

they may come from
the same parent body.

The idea is that
millions of years ago,

that parent body was
struck by another space rock.

In the aftermath, the
dust literally settled,

as the leftovers were drawn
to each other by gravity.

This is material that has
sort of come together,

clumped itself together,

and then through
its own gravity,

has held itself together.

Bennu and Ryugu are
collections of massive boulders,

rocks, and pebbles that
formed at about the same time.

You might even call
them distant cousins.

Why these cousins have
the same spinning top shape

is a mystery the
teams hope to unravel.

So it's kind of cool that

we're both going to
very similar objects

that might even be related.

But there's one
baffling difference.

Osiris Rex has detected minerals
inside of Bennu's rocky surface

that contain the
remnants of water.

Water, like carbon,

is a key ingredient for the
development of life on Earth.

We had a very strong signal

that there's a lot of water
on the surface of the asteroid.

Maybe as much as ten percent

of the minerals contain
water inside them.

In comparison, cousin
Ryugu is parched.

We don't have that
much water, it's very dry.

So fundamentally different.

Also different

is Hayabusa2's strategy
of finding a landing site.

They deploy several
robots to the surface,

equipped with a
suite of instruments.

So you have a camera,

you have something to measure
the temperature of the surface,

and something to
measure the composition.

Some bots traverse
the surface by hopping.

The whole robot can rotate,
kick the surface, and then jump.

The bots collect
data and images.

The team picks a sample site

and releases a target
marker to mark the spot.

In February 2019,

they make their first attempt

to collect a sample.

Touchdown is very risky,

so we are very nervous.

Finally...

The signal comes in.

The whole control
room was so excited.

I remember the scream
of my Japanese colleagues

when we knew this was a success.

NARRATOR; Later, they receive a
series of images from the spacecraft

as it touches Ryugu's
surface and pulls away.

What they see
surprises everyone.

Even though the surface
of Ryugu looks like

it's covered in boulders,

as soon as a force was applied
to the surface of that asteroid,

you saw small particles
flying everywhere.

The surface is very fragile,

maybe softer than expected.

That actually gives
me a lot of confidence

in our sample
collection technique.

I think even if we made contact

with one of those
boulder-y surfaces,

the material is probably
very loosely bound,

easily broken apart.

So, in the worst-case scenario,

where we hit the
top of a boulder,

I still think we're gonna
get a lot of sample.

While this appears
to be good news

for the Osiris Rex team,

there's no guarantee that
Bennu's surface will be similar.

In spite of all of
the information

that we've collected so far,

there are still some things

that we just can't
know about Bennu

until we actually make
first contact with the surface.

When we go to see an asteroid,

all our assumptions
are usually totally...

Messed up.

They turn our
understanding on, on its head.

A few months later,

the Hayabusa2 team
goes for a second sample.

This time, they blast
a copper projectile

into the surface of
Ryugu to form a crater,

in search of the most pristine,
untouched sample they can find.

The crater does
excavating for us.

It takes that uppermost
layer of the surface

that's been exposed

to solar wind or
micrometeorite bombardment

for hundreds of thousands
or even billions of years,

and removes it
and allows us to get

a little bit further
into the subsurface.

They collect this
buried treasure

from inside the
crater and stow it.

Although Hayabusa2
has made two attempts

to grab a piece of Ryugu,

the team has no way of
measuring their bounty.

Unlike Osiris Rex,

that must wait until the
spacecraft returns back home.

December 2019.

The Osiris Rex
team has been taking

thousands of pictures
of every inch of Bennu,

searching for the
best site to sample.

Our current image
count is 53,000 images.

Osiris Rex will use these
tens of thousands of images

to navigate its way
to the sample site.

So after we completed

our global mapping
campaign of the asteroid,

we identified a sample site,

about 55 degrees north latitude,

so pretty far up.

The team christens
the site Nightingale.

Near the north pole of
Bennu, this crater looks ideal.

It looks great from a
sampleability perspective.

It's got the finest-grain
material over a large area.

So, if we could get in there
and contact the surface,

we're highly confident that

we're gonna be able
to get a sample from it.

But nearby is one
major obstacle.

It has a giant rock just off

to the southwest of the crater.

I give it the nickname
Mount Doom

from "The Lord of the Rings."

Bennu's Mount Doom is as
tall as a two-story building.

And we got to
fly right over that

and then down into the crater
in order to get the material.

The size of the crater
where they will grab a sample

is not what they hoped for.

This circle is the area the
team thought they needed

in order to safely
touch the asteroid,

about 164 feet wide.

There is nowhere on the
surface anywhere close to that

that is free of hazards.

The size of the new
"safe" area in Nightingale

is about 26 feet.

Our landing area

is much smaller than
what we had anticipated.

The TAG site right now is
about several parking spaces.

So it's a lot smaller area
that we need to target.

We have to eke out every bit
of error that we can in order to

get this bull's eye
TAG and get in there

and collect the sample.

To safely guide the
spacecraft away from danger,

the navigation team needs
extreme-close-up images

of Nightingale.

We can image an
object the size of a penny

on the surface of the asteroid.

These two bright
spots circled in green

are in the center
of Nightingale.

Each one is slightly
smaller than a penny.

With this level of detail,

the spacecraft should
know precisely where it is

as it makes its
way to the surface.

It's a very
intelligent spacecraft.

It can make some
decisions on its own,

and if it sees things go awry,

it goes ahead and,
and takes care of itself.

The spacecraft
autonomously will be checking

its estimated position.

And if it's predicting us to
come down on a hazard,

we'll have to abort

and try again.

When you're flying by Pluto
or going into orbit around Mars

or landing on the
surface of a planet,

it's got to happen
exactly according to plan

and there is no second chance.

Osiris Rex, we're more
like a hummingbird.

We can go in, we can go back.

We can go in, we can go back
until the spacecraft decides,

"Yep, I'm coming in, place
looks good, let's go ahead

"and commit to the
descent to the surface

and collect that sample."

April 2020.

A tough job gets even tougher

as the team conducts a rehearsal
of TAG during a pandemic.

The whole work-at-home shutdown
orders that started coming in

in March, they really hit our
team at the worst possible time,

because we were right in
the middle of the final testing

and preparations for
this rehearsal for TAG.

There was a handful of
people that had to go in

to Lockheed Martin, but
the vast majority of the team

watched from home.

We were handing the
reins over to the spacecraft

to autonomously navigate
itself to the surface.

We brought the spacecraft
to within about 60 meters

of the surface of Bennu.

Seeing for the first time the
TAGSAM head descending

towards Nightingale,

it just kind of made
it all much more real.

We were right on target

and the onboard navigation
system worked perfectly,

really exceeded all
of our expectations.

It's really a
testament to the team

and how they were
able to pull it off.

If there's one thing that was
a disappointment for the team,

it's just that after working so
hard to get to this milestone,

such a huge milestone
for the mission,

there was a sense of
disappointment, I think,

that we couldn't be together
as a team to celebrate it,

to celebrate the success.

October 20, 2020.

After two rehearsals,

the team finally
gathers together

as Osiris Rex attempts
to touch the asteroid

and grab a piece of it.

I was sweating and just nervous

waiting for the
signals to come back.

It's 0.7 meters.

The last ten minutes, as the
spacecraft was descending

towards the surface
of Bennu, was unreal.

There were so many feelings

running around in my head,
it's sort of hard to articulate them

in a small number of words.

It was this
slow-motion thrill ride.

O. Rex has descended
below the five-meter mark.

At the crucial moment,
Osiris Rex makes the decision.

The hazard map is go for TAG.

: Contact expected
in 50 seconds.

We're going in, we're going in.

And we have touchdown!

We did it!

Finally, Osiris Rex touches
the surface of Bennu,

the culmination
of years of work.

I'm in awe, really.

Everything went
phenomenally well.

We came down only two TAGSAM
heads away from our target.

I mean, I couldn't have
done it better if I was sitting

on the spacecraft
guiding myself down.

I mean, I can't believe
we actually pulled this off.

It was a good day.

In a few months, the
spacecraft will leave Bennu

on a two-year journey back home.

In 2023, a capsule containing
precious rock and dust

will parachute down
to the desert of Utah,

and the next step of the
exploration of Bennu will begin.

We need to keep exploring.

It really goes a long way into
understanding who we are,

how we got here,

and what our long-term
prospects are on this planet.

Humans look for the unknown

and consider it a challenge.

They want to explore
what's out there.

Why?

Maybe it's built into our DNA.