Original subtitles

(dark mysterious music)

- [Narrator] Asteroids.

Remnants from the birth of our solar system.

From planetoid-sized monsters down to tiny pebbles,

they have orbited our sun for billions of years.

We have seen some up close,

even touched their surface.

We count their numbers, chart their courses,

and keep a wary eye on these mountains in the dark.

(exciting music)

(dark mysterious music)

Several spacecraft have ventured out

towards these rocky worlds.

Some have touched down and taken samples

with surprising results,

then returned them to Earth.

Scientists have found these remnants to be complex

and full of secrets.

There are different types of asteroids,

and two new robotic probes are ready to study

some of these unique targets.

One is called Psyche,

and it is perhaps one of the most interesting.

(rousing music)

- 16 Psyche is an asteroid that orbits the sun

out between Mars and Jupiter.

It's called 16 Psyche because it was the 16th asteroid

discovered, and they were all being named

after gods and goddesses at that time.

- So the Psyche mission is going to visit an asteroid

which is called Psyche, and it is a large metal asteroid,

a unique body in the solar system.

150 miles in diameter, approximately,

and made of 40 to 60% iron nickel metal.

That makes it a unique body in the solar system.

We visited worlds made of ice, and worlds made of rock,

and worlds made of gas before,

but we've never visited a metal world.

So we'll get to see something unique

and different for the first time.

- All the rocky planets that we know of, the Earth,

Mercury, Venus, Mars, and the Moon

all have got a metal core in their center,

and especially for the Earth,

it's the source of our magnetic field,

which may be tied to holding onto our atmosphere

and making our planet habitable.

There's a lot of study that's going on to understand that,

but we don't know a lot about our core.

What we've learned about it, we learn indirectly,

because we can't go there,

and so Psyche gives us the opportunity to visit a core

the only way that humankind can ever do.

And so we hope to learn something about what's inside

the Earth and other rocky planets by visiting Psyche.

But it also tells us about the processes

in the very beginning of the solar system.

It helps us understand how planets form in the first place.

(exciting music)

- [Kalyani] So the Psyche payload consists

of three science instruments.

One of them is what's called

a gamma ray neutron spectrometer.

It's actually two separate pieces of hardware.

One is the gamma ray spectrometer,

and the other one is the neutron spectrometer.

Both combined study the elemental composition of Psyche.

- If you know the surface composition,

what is made of in terms of iron and nickel

and silicon and oxygen,

you can then start to say something about its history,

and how it formed, and how it evolved.

- By using gamma ray spectroscopy

we can measure those elements remotely.

We don't have to touch the surface,

we don't have to dig into the surface.

- For Psyche we're building kind of what

we call the Cadillac.

It's a very high precision, high sensitivity instrument.

It's very similar to the messenger instrument.

- That technology that we developed

for the Messenger spacecraft gave us a huge headstart

going to Psyche

- For our types of instruments, we don't get

to fly 'em very often,

so when we actually get selected for something,

that's a big deal for us,

where we can take what we learned from the prior missions

and implement it now and make an even better instrument.

- Only one body like this that's this big

and made of metal in the solar system.

So the big mystery is where did it come from?

How was it created?

One of the theories about it is that it was once the inside

of a forming planet, because the planets that we know,

Earth, Mars, Venus, Jupiter,

have metal cores inside of them.

So this may have been the metal core that was forming

inside of a baby planet, which then collided

with other planets that stripped off, forming planets,

that stripped off that rocky mantel,

just leaving a piece of that core in space.

And if that's the case, then by studying this body

we'll be able to study the cores of planets like our own,

the Earth, in a way that we can never do otherwise.

(bright music)

- Psyche is a larger asteroid in the main belt

that is in between Mars and Jupiter.

Our experience so far in terms of exploring

the solar system has been with either rocky or icy bodies.

What's particularly interesting about Psyche

is we think it's a metallic object.

We have a common understanding perhaps of how regular

common rocks behave, but metal behave

in a very different way.

What I contribute to the mission is trying to

understand how cratering and the process of collision

and interaction of work for a metallic object.

And we'll use this information then

to understand what we see at the surface once we get there.

What we did is take an iron meteorite,

put it in in the chamber, and use it as a target

for our input experiment.

And when we're shooting quartz bid

at high speed in order to produce a crater.

Everything has been filmed with the high speed cameras,

so we have a tremendous amount of data that shows

in high resolution what happened during the contact,

during the explosion, and how the crater forms

on the surface, so everything has been documented

in great details.

Here we have a piece of the Gibeon meteorite,

and what we see here is a crater that was produced

as a result of one of our experiments.

And traditionally with rocks, the rim would be blasted away

and would be a sort of flattish feature.

But here we see these flaps

that basically are frozen into place,

and this is because the metal is much harder than rocks.

And so you can then retain this interesting morphology.

There's gonna be a very exciting phase

of the mission when we actually start gathering data,

and there's gonna be lots of surprises.

I just can't wait to be there

and see whether or not there is any resemblance

with this model or not.

(bright music)

- There is nothing like the experience of sitting on console

on launch day, and hearing all the people go around and say

we go for launch.

And then finally getting to say yourself,

we are go for launch.

It's the culmination of all those years of effort,

and all those hundreds of people working.

And so it's super exciting when you actually

finally say we're go, and we're gonna get

that beast into space.

We're gonna go launch and do a Mars gravity assist,

go by planet Mars, and then continue onto the asteroid

using electric propulsion.

(bright inspiring music)

- I think no matter what we think it is right now,

and how much we hypothesize what it might look like,

I think it's gonna really surprise us and change our views

about our solar system when we get there,

and it's an incredible opportunity to be a part

of the team making that happen.

(bright piano music)

- [Narrator] The Psyche mission has suffered

several launch delays.

However, it should be underway in the next year or two.

- [Announcer] 3, 2, 1, 0.

(space engine rumbling)

Lift off.

Atlas V takes flight.

- [Narrator] Another ambitious mission that has launched

is Lucy to study several asteroid targets.

- [Announcer] All clear.

- So Lucy is going to survey eight asteroids

over a 12 year mission life.

The first asteroid is in the main belt asteroids,

it's Donald Johanson.

And then the remaining asteroids are the ones

that we call the Trojans.

And because we believe that they are remnants

of our solar system, by studying their geology,

as well as their composition and their mass,

then that will give us insight into planets,

planet formations, and in particular the outer planets.

- The Trojan asteroids, which are located

in these Goldilock zones of gravity-stable orbits,

or in between the sun and Jupiter,

are really leftover fossils from the formation

of the solar system.

And these fossils are around 4 billion years old.

And when the solar system was forming, they were brought

into these locations, and the Trojan asteroids

which have been there since the formation

of the solar system, are these last unexplored remnants

from the cosmic neighborhood creation.

And we're extremely excited to go and visit them

because of our total lack of understanding

of exactly what is out there.

And so it's gonna be extremely exciting

when the Lucy spacecraft explores them.

- Some of the most important planetary science questions

we're trying to answer are focused on the origin

and the evolution of the solar system.

Asteroids and other small bodies are really important keys

to understanding that history.

Amazingly, many of these mysterious worlds

have been altered very little in the 4.6 billion years

since they first formed.

The relatively pristine state makes comets, asteroids,

and some meteorites, wonderful storytellers

that have preserved clues they can share with us

about conditions in the early solar system.

In particular, by studying the Trojan asteroids,

we can gain more insight into the history

of the outer solar system in the giant planets,

Jupiter, Saturn, Uranus, and Neptune.

We actually find asteroids across the solar system,

including near Earth asteroids that are in orbits

that periodically bring them close to Earth,

main belt asteroids that orbit the sun

between Mars and Jupiter,

the Trojans that Lucy will explore,

and the Copperbelt, just beyond Pluto,

which contains some of the most primitive objects

in our solar system.

Not all of these asteroids are the same,

and Lucy is part of a collection of ambitious missions

to study the diversity of these asteroid populations

that'll help us fill in more pieces of that cosmic puzzle.

(rousing music)

- [Narrator] Lucy will slingshot out from Earth's orbit

and pass by the first target, a C-class

or carbon-based asteroid named Donald Johanson,

after the famed archeologist.

Lucy will continue to the orbit of Jupiter

and intercept four more targets.

Eurybates, Orus, Leucus and Polymele.

Some are DMP class asteroids never seen before,

and theorized to be rich in volatiles and organics.

The probe will then return to Earth

for another gravity assist to the trailing Trojans

of Jupiter, intercepting the twins Patroclus and Menoetius,

more P-class objects.

- And Lucy spacecraft was named after the Lucy Fossil,

because we will be studying asteroids,

which are the fossils of planet formation.

But the Lucy spacecraft and the Lucy Fossil was named

by archeologist Donald Johanson and his team,

because apparently when they discovered the hominid,

they were listening to The Beatles song,

"Lucy in the Sky with Diamonds".

Now we do have a diamond.

It's our beam splitter, which is on the LTES instrument,

which is used to split the beam,

is actually made of diamonds.

- My job as a mission architect here at Lockheed Martin,

it's very interesting, and it sort of encompasses

the biggest picture of the mission.

What is the trajectory?

What sort of propulsion do you need to fly that trajectory?

What does the spacecraft look like?

So in the case of, for example, Lucy, it's like okay,

it's going out five times further from the sun

than the Earth is.

And so it's gonna need big, huge solar rays

just because of that.

- [Cathy] Lucy has three scientific instruments

onboard the spacecraft, and we'll also be using

two of the spacecraft subsystems to contribute

to the science investigation.

With the LORRI instrument

we'll be able to get panchromatic images,

which will tell us about the geology,

and the crater history, which gives us

the age of the surface.

With the TES instrument, we'll be able to measure

the temperature of the surface at different points,

and with the Ralph instrument we'll be able to

measure the composition of the surfaces.

The Jupiter Trojans, they have a variety

of surface characteristics.

They have different colors,

and different surface compositions,

and that leads us to believe

that maybe they formed somewhere else.

- [Narrator] After launch, the Lucy probe failed

to lock one of its solar panels in place.

Engineers are working on a resolution to this problem.

- The Lucy spacecraft will travel 4 billion miles

over its mission,

and it is a very sophisticated, well-orchestrated trajectory

that gets us there.

- I cannot wait for those gorgeous images

that our instruments are gonna take,

and bring back to Earth.

What that's gonna tell me and the world

is how gorgeous these objects are,

what secrets they have to hold,

and it's gonna start us unlocking these mysteries

of the solar system that are out there.

I can't wait, and words can't describe just how excited I am

to share with everyone these images

when they first come back.

- [Narrator] This animation is drawn

from the recent data release of the ESA Gaia satellite.

It reveals the locations of the larger asteroids

within our solar system.

This tapestry of orbits shows that several

near-Earth objects cross our orbital plane.

Geological history records that some have hit the Earth

with devastating effects.

(slow tense music)

- We've seen asteroids come through the atmosphere

and kind of explode, and cause some damage,

and thankfully so far nothing recent enough

that it really has a large, large impact

on our civilization, but it could happen.

- There are multiple different ways

that you might attack the problem of,

oh no, doomsday asteroid is inbound.

One of those ways is a kinetic interceptor,

which is what DART is working on.

- [Lori] As part of planetary defense,

DART, which stands for Double Asteroid Redirection Test,

its mission is to impact an asteroid in a binary system.

- The reason we're doing this test is to try and prove

out the technologies that would be needed to,

say, save Earth if an asteroid were coming our direction

and we needed to adjust its trajectory

so that it would miss the planet.

- SMART Nav is the autonomous algorithm on board,

and the purpose of SMART Nav is to identify

Dimorphos, which is the smaller of the two asteroids

in the Didymos system.

And we send maneuver commands to the spacecraft

for the spacecraft to hit Dimorphos.

- And we understand where about 40% of those asteroids are.

We know that no known asteroid

is a danger to the Earth right now,

but the concern is about the asteroids

we don't know about yet.

And if we should ever discover an asteroid

that's on a collision course with Earth,

we wanna be able to discover this years in advance

so we can give the asteroid a push, not to destroy it.

We probably wouldn't be able to do that anyway.

But just to prevent that collision.

And the DART mission, the Double Asteroid Redirection Test,

is our first test of one way of doing that.

(soft atmospheric music)

- [Narrator] Launched aboard a SpaceX Falcon rocket,

DART is well on its way to its target.

- So the way an ion thruster works is that it utilizes

electrical energy to ionize propellant and accelerate it

using electric and magnetic fields.

What it next does is that it increases the power level,

you get more thrust out of it, it's more fuel efficient,

it lasts longer, basically kinda improves things

in almost every way, and makes it very beneficial

for end users to utilize

- [Luke] When they're rolled out and fully deployed,

they're almost 10 meters long.

This is the last time that anyone will ever see

these arrays fully deployed.

Once we stow them here at DSS,

they will not be deployed again until we're in space

on the DART spacecraft.

Part of our detailed inspection

entails Andrew looking at the cell by cell

on these arrays again that are almost 10 meters long.

He'll look at them at different wavelengths of light,

different angles, just to assure ourselves

that we've found every anomaly possible in these cells,

and they're fully characterized with the entire array,

and we know exactly what we have,

and the condition it's in when we launch.

- DART's going to a binary asteroid, a double asteroid,

for two really good reasons.

The little asteroid, Dimorphos, which is in orbit

around the big asteroid, Didymos,

that asteroid is about the size of object

that we would tend to be concerned about.

The most abundant asteroids are the small ones.

And this one, about 160 meters across,

or about the size of a football stadium,

is large enough that it really would cause severe damage

if it struck the Earth.

Now, by impacting, by doing our experiment,

a kinetic impact experiment on the small moonlet asteroid,

we're able to measure our effectiveness

in deflecting the asteroid by watching the change

in the orbit of the little asteroid around the big one.

It makes that measurement a lot more precise

and a lot easier to do with telescopes on Earth.

The other reason we're doing it is that the presence

of the large asteroid there keeps the little one

in orbit around it as the pair go around the sun.

So that means that this asteroid, which is not a danger

to Earth now, will never become a danger to the Earth

because of anything that we do in the DART mission.

(exciting music)

DART is carrying a small cube set,

it's called the LICIACube.

It was contributed by the Italian Space Agency.

And its job basically is to watch the impact

from a little distance away.

It's riding along on the DART spacecraft

and it's going to be deployed a few days

before the kinetic impact.

It's going to maneuver and offset itself

to the side so that it doesn't run into the same asteroid

that DART is running into.

And it's got two cameras on it

that are going to try to,

first, catch the actual impact of DART on camera,

but then more importantly, see the ejecta,

the plume of material that's blown off the surface

of the asteroid and how that develops.

If we're fortunate, we'll be able to see the impact crater

newly formed by the DART impact.

And then, of course, LICIACube is going to do something

that DART can't do, that is fly past the asteroid,

look back, and get the full three dimensional shape

of the object that we hit, which we won't know

until we actually get there.

- [Narrator] One other threat to Earth

is the interstellar object passing through our solar system.

They arrive without warning, fast moving,

and having no known orbit.

Another hazardous mountain in the dark.

(exciting music)

(asteroids whooshing)