The impetus for the DART mission was to answer the question “If
an asteroid one day is discovered heading for the earth,
what would you do?” Very, very broadly, we needed to demonstrate that we could
intercept a body in space, that we had never been to,
and that we could change that body's orbit.
Pre-DART, everything was theoretical.
There hadn't been any in-flight demonstration of a technology
that could potentially prevent an asteroid from hitting the Earth.
And it's exciting that we've taken this first step.
Earth has been hit by asteroids for billions of years.
This has happened in the past.
It will happen in the future.
And planetary defense is trying to prevent those impacts
from having a bad effect on us here on Earth.
There have been theories about what kind of things
we could do at an asteroid if an asteroid was coming towards Earth.
However, the most practical one and the one you have to try it first
is go and hit an asteroid.
The kinetic impactor technique is basically
you have an asteroid that's moving in a direction at a speed
that is going to take it to intersect the earth.
And you launch a spacecraft and collide it with the asteroid
so that changes the asteroid's orbit so that it no longer hits the Earth.
If you do the experiment
at a binary system, this is two asteroids, one of which orbits the other,
you're able to measure that change using telescopes from the Earth.
There's only a very small number of asteroids that you can do
this experiment at and Didymos is by far the best.
That's made this a very cost effective way to do this
first test, a very focused way to do this first test, taking this
from something that was just theory to now a reality.
3 2 1
and liftoff of the Falcon nine and DART.
Didymos is by far the smallest object it's ever been targeted by NASA's spacecraft.
We're hitting it at several times the speed of a rifle bullet,
six and a half kilometers per second.
The spacecraft has to do everything itself.
Find the asteroid, guide towards it, impact it...
SMARTNav I always considered the brain, so it was making course corrections based
on our trajectory to the Dydimos system and then finally to the Dimorphos.
Ejecta is all of the dust and rocks and in some cases, boulders
thrown off of the asteroid,
giving the asteroid an extra push by that material that's getting shot off.
We wanted to observe it, know how much there was, how fast It's
going, to help us determine how much deflection
does the kinetic impactor produce when it hits the target.
The simulations and the theory ahead of time predicted
a wide range of results, but without actually doing the experiment,
there was a lot of question about how it would work out.
Honestly, the day before
impact, I slept strangely well.
We've tested our spacecraft on the ground.
We tested our spacecraft in flight.
We knew it like the back of our hands.
Hundreds of people across APL contributed to this.
Scientists around the world
involved telescopes ready to go to watch the effect.
Yeah.
I was really happy that the day was finally here and we were going to do this.
And tonight we're following the real-time journey
of the DART spacecraft and its planned collision with asteroid Dimorphos.
One of the bigges challenges was we cannot even see the target because it's
behind the other asteroid until, you know, one and a half hours before the impact.
We slowly started getting closer and closer in.
At 4 hours out, our spacecraft became completely autonomous.
Okay. Do we see the second moon?
If we don’t see it there’s no way the spacecraft sees it.
And we were all huddled around our phones, you know, looking at the team Slack.
And once we saw that we could see two...
Didymos and Dimorphos as separate dots I said, “we're good.
We're going to hit it.”
We start seeing the features on the ground, boulders and such huge boulders.
It was the most amazing feeling.
And even talking about it right now, I'm getting goose bumps.
Are we there yet? Are we there yet?
Are we there yet?
The last the image came in, it was less than a second prior to impact.
You could see the red on the camera and...
I don't think
I've ever cheered for losing the signal with the spacecraft before.
But definitely did that time.
I was sitting on the lawn here.
Within 2 minutes, people were saying, “Hey, it's getting brighter in Kenya.”
“Hey, it's getting brighter in South Africa.
We think we're seeing this.”
We started getting the reports in front of the telescopic observations.
“Oh we saw there was an immediate
dramatic brightening of the system.” LICIACube the Light
Italian CubeSat for Imaging of Asteroids contributed by the Italian space agency.
It started taking its images and it made its close flyby 3 minutes afterwards.
And what you saw is these huge ejecta streamers.
People were trying to measure
how much we actually changed the orbit of the asteroid.
We were hoping for something like 3 to 10 minutes.
We actually made a period change
that was more like a half hour and we made a lot of ejecta.
It means that you can deflect a larger asteroid than you thought you could before
if you had less warning time, let the asteroid
get closer to you before you detect it.
You could still be able to make it miss the Earth.
We're learning so much more about the surface properties
of the asteroid, the cohesion properties of the asteroid.
If we were to find something, we now have an option, another tool in our toolbox.
We take all of the information that we have learned from DART and we can
now directly apply it for the future of planetary defense operations.
It really pushes the capabilities of what we could do on board
the spacecraft and what the mission concepts could be in the future.
So it's just the beginning.