All language subtitles for 9DAC42141EA009FFFE1E2D65D024DD97_eng

Is the cost of space
exploration really worthwhile?

It's a question that crops up regularly.

Could the money be better spent elsewhere?

Even if it were, one space program
would still have to remain in place.

That's the planetary defense program,

to locate identify and deflect
any wayward asteroid from hitting Earth,

and destroying our civilization.

At the last count, there were 15,000
potentially dangerous candidates

close to Earth.

It's now over two years
since the Rosetta mission

reached it's target rendezvous, 67P.

It's been an audacious mission,
gaining unprecedented forensic knowledge

of the comet’s surface, interior
structure, composition and history.

We’ve noticed
that there is not ice on the surface.

We would be able to see that...
at least not large patches of ice.

You don’t have skating rinks
on this comet.

Uh, and we also see gas in the coma.

We see evidence of
carbon monoxide and carbon dioxide

and the elements themselves,
carbon and oxygen,

in different parts of the coma.

And we discovered that this carbon

was actually a very complex material,
very complex carbon,

very different from the simple molecules
that we would expect to find there,

so we don’t see amino acids or alcohol or this kind of molecules
which is observed in the gas.

But we see something much more complex,

and very rich in carbon
and poor in nitrogen or hydrogen

compared to these other materials.

In particular what we have observed

is that the nucleus is composed of
a mixture of materials, like minerals,
like silicates and sulfides

which have been formed in the inner part
of the solar system, close to the sun.

Because the comet is kept
in a very cold environment,

we don’t expect it
to have very high temperature phases

so it can be that this material
was formed closer to the sun,

and was then was brought
to the comet later.

And this for us was a surprise
because we knew it for the minerals

but not so much for the organics.

So it seems that the organics
also can be transported

over large distances in the solar system.

The most prominent,
the most exciting change on the surface,

I believe it is still the big drop in the
Imhotep plateau which was three meters

and 100 meters in height
and 100 meters in radius.

But we have seen smaller scale features

like a boulder which was
at least 50 meters big, ten tons heavy

which, well on the comet it’s just
a chocolate bar of 100 grams or so,

but still it’s a massive thing
which has moved by 140 meters,

likely due to activity
but we don’t know the real reason.

It was time to decide
what to do with Rosetta

now its mission was complete.

One option was to land it on the comet.

There were discussions

about what would be the priority
for the end of mission.

So there were several scenarios
put together

and one of the options was to do
those very close flyovers

and, I mean, in terms of
the science objectives,

that was the one that will bring us
the more interesting scientific results.

So it was decided by the science
working team to go for this scenario.

So, yes, that's a very, uh first...
again, another first of Rosetta.

Rosetta's trajectory
was altered to spiral into the comet,

taking photos as it closed in.

Rosetta's blown it all open.

It's made us have to change our ideas of
what comets are, where they came from

and the implications
of how the solar system formed

and how we got to where we are today.

and we've only, like Philae,
just scratched the surface

And it's important to note Rosetta mission
is both the lander and the orbiter.

Together they have made it possible
to do the science,

to make the breakthroughs that we have,

and we have only just scratched
the surface.

We have decades of work to do
on this data,

so the spacecraft may end
but the science will continue.

That's what we're here for.
That's what this mission is for.

We just have
had a loss of signal at the expected time,

which is another outstanding
performance from flight dynamics.

So we'll be listening for the signal
from Rosetta for another 24 hours,

but we don't expect any.

And so, this is the end of the Rosetta
mission. Thank you and goodbye.

One major problem
faced by Rosetta and it's Philae lander

was the low gravity.

When the lander's harpoons
failed to secure it to the comet,

it tumbled and bounced
until it was lost in the rugged terrain.

But engineers love a challenge,

and they have already come up with
a novel answer for next time...

It's called the Hedgehog.

So we said together
JPL and Stanford

have been working
on a totally different rover concept

that is well suited to these environments,
called Hedgehog.

Instead of rolling around on wheels,

the Hedgehog design actually puts
three flywheels on the inside of a cube.

By spinning these flywheels up very slowly
and then very quickly applying a brake,

which transfers all the momentum
from the flywheels,

we're able to cause Hedgehog
to either hop, or tumble,

or perform small adjustments.

We've done many tests here on Earth
in gravity off-loading test beds.

Recently we have flown two
Hedgehog prototypes on a zero-G aircraft.

In these tests, we demonstrated

that we would be able to perform
on a comet or an asteroid.

Hedgehog doesn't have a right way up.

Instead, it can tumble over the surface
and come to rest on any one of its faces

and still work perfectly.

JAXA's sample mission
from asteroid Itokawa

from the last decade
returned mixed results.

It did, however, teach engineers
and designers many lessons

about the difficulties
of collecting samples from asteroids.

Their second attempt
is currently underway.

Hayabusa 2 is coasting
towards another asteroid, Ryugu,

and should reach its destination
in the middle of next year.

This new and improved robot
has several new capabilities built in.

They include ion engines,
navigation and attitude control systems

and an explosive device
to dig into the asteroid

and return material from within it.

Also on board are a probe
and three miniature rovers. A secondary probe launched with Hayabusa
called Procyon

had an engine malfunction
and will not complete its mission.

NASA's attempt at an asteroid
sample return is also underway.

OSIRIS-REx was launched from
Cape Canaveral Air Force Station's

Space Launch Complex 41,

and is on it's way to intercept
the near-Earth object Bennu.

...2, 1...

...and liftoff of OSIRIS REx.

It's seven year mission... to boldly go
to the asteroid Bennu and back.

Bennu is a B-type asteroid
of approximately 500 meters diameter.

It completes an orbit around the sun
every 1.2 years,

and every six years
it comes very close to Earth.

These close encounters mean
there is a high probability

of Bennu's impacting Earth
in the late 22nd century.

Bennu’s size, primitive composition,
and potentially hazardous orbit

make it the ideal
OSIRIS-REx target asteroid.

It will first survey the asteroid
to find an ideal touchdown site.

Understanding the shape of asteroid Bennu

is going to be absolutely fundamental
to understanding the geology

and putting it in context.

The other reason you really need to
understand the typography extremely well

is that when we're going in
to take a sample,

it's a very, very fine measurement.

And so if you're coming in, you've got
the sampling head at the end of this arm

that has to come in
perfectly square to the surface.

If you don't understand shape,
sort of at a 30 centimeter scale,

you're not going to be able
to collect a sample.

The seven year mission will see ORISIS REx
touch down for only a moment

to retrieve a surface sample
of the asteroid,

then return to Earth
to deposit the sample return capsule

somewhere in Utah in 2023.

NEOWISE has been a reliable workhorse,
operating long past its planned lifetime,

but its mission will
eventually come to an end.

Engineers estimate it will move
into too much sunlight to function.

However, the team is eyeing a new space
telescope, one with a little more muscle.

The near-Earth Object Camera, NEOCam,

is specifically designed
to hunt asteroids.

the proposal has been funded
for further study by NASA.

Undergoing preliminary work
is the Asteroid Impact Mission, AIM,

who's launch could come as soon as 2020.

A joint NASA ESA project would see ESA
launch AIM to a binary asteroid, Didymos,

and its satellite, Didymoon.

They were discovered over twenty years ago

and are part of a group of asteroids
called the Apollo group,

near-Earth objects that cross Earth's
orbit and are a potential threat.

ESA's part of the mission
is to orbit and study the asteroids,

in particular, their orbits
around each other.

AIM will rendezvous
with asteroid Didymos in June 2022.

The first thing it will do
is to take high resolution images

so that we can reconstruct
a 3D shape of the moon,

and then we will use this data to test
a new optical communications system

with a laser transmitting these images
down to Earth in a very quick way.

After we do these measurements
and we have the 3D model, we will sound the interior structure
of the asteroid

by deploying a small micro lander
on its surface

that will emit small radio waves

that will cached by AIM
and reconstruct the interior structure.

After we have done these measurements,

the spacecraft will move away
about 100 kilometers from the system,

waiting for DART to arrive
and impact the moon.

NASA's contribution DART

is a kinetic impactor traveling at
six kilometers per second.

Once the impact has occurred,

then we will look at the ejecta
and the dynamics of the ejecta cloud,

we'll come closer to the moon
and repeat the same sets of measurements

so that we can understand the changes
in the interior structure,

and the shape and the morphology
of the crater before and after the impact.

AIM is the first mission to test
the kinetic impact deflection technique.

It's the first mission that will prove
deep space optical communication systems,

and it's the first mission to deploy
CubeSats into space

and test inter-satellite
communication systems.

Also, it will be the first mission
to rendezvous with a binary asteroid

and characterize it so that we can
understand how these bodies are formed,

which is highly linked
to the way the solar system was formed.

By measuring Didymoon’s
physical properties

and its orbit
before and after DART's impact,

scientists will gain valuable knowledge
that can be applied to a real threat,

should it ever occur.

NASA is proceeding with long-term goals

such as a manned
sample return from an asteroid.

A robotic spacecraft would locate
and capture a small asteroid,

and redirect it into a lunar orbit.

An Orion capsule
would then rendezvous with it.

Astronauts are now training and developing
techniques for such a complex mission.

There are still many things to be learned

about asteroids
and the dangers they might pose.

As this animation shows, the inner
solar system is awash with asteroids.

Many of them are near Earth's orbit.

Some even cross our path
from time to time.

All these possible hazards
need to be identified,

their orbits must be calculated to a high
degree, and their threat assessed.

Finally, we need to develop the technology
to mitigate any danger to our planet.

There are several groups of asteroids
based on where they orbit.

Those within Earth's orbit
are Atens and Amors,

while the Apollos cross Earth's orbit.

The majority of asteroids reside
in the main asteroid belt

between Mars and Jupiter.

then there are the Trojans, trapped
within Jupiter's gravitational pull.

And beyond that, other remnants
of the solar system's formation

can be found
caught in the orbit of Uranus.

There is a great deal more
to be learned and understood

about these other asteroids.

To this end, two new asteroid missions
have been planned and funded

through the development stage.

They will study
two very different types of asteroid.

The first of those missions is Lucy,

which will visit a target-rich environment
of Jupiter’s mysterious Trojan asteroids.

The mission will launch in October 2021,

and fly by its targets
between 2025 and 2033.

In all, Lucy will study six Trojans
and one main belt asteroid.

Trojans are fossils of planet formation,

and so will supply important clues to the
earliest history of the solar system.

The second is Psyche.

This mission will explore
one of the most intriguing targets

in the main asteroid belt:

a giant metal asteroid,
known as 16 Psyche.

About three times farther
away from the sun than the Earth is,

this asteroid measures
about 210 kilometers in diameter,

and, unlike most other asteroids
which are rocky or icy bodies,

is thought to comprise mostly
metallic iron and nickel,

similar to Earth’s core.

Psyche could possibly be
the exposed core of an early planet,

which lost its rocky outer layers in
violent collisions billions of years ago.

The mission will help scientists
understand how planets and other bodies

separated into their various layers...

cores, mantles and crusts.

Psyche will map features, structure,
composition, and magnetic field,

and examine a landscape
unlike anything explored before.