Hello.
I am Karen Fox with NASA's Office of Communications.
And we are here today at the Johns Hopkins University Applied Physics Lab
in Laurel, Maryland, to talk about
NASA's first test for planetary defense.
This is the double asteroid redirection test mission,
which is going to test one way to change and asteroid's movement in space.
We're planning to launch in late November.
Everybody in the room here today is vaccinated.
We are following CDC and APL guidelines
for social distancing and for masking.
However, speakers will be taking off their masks when they talk.
Our speakers are going to be Lindley Johnson,
the planetary defense officer at NASA headquarters in Washington.
Nancy Chabot the coordination lead on Dart here at APL.
Elaina Adams, the Dart Mission Systems Engineer here at JPL.
And Andy Cheng, Dart Investigations Team Lead at APL.
After they speak, we will open up
the phones to Q and A from our media.
You can press star one in order to get into the queue for those questions.
And additionally, we will be taking questions
from social media at hashtag Ask NASA.
So with that, let's get started with Lindley Johnson, who is going to tell us
about NASA's planetary defense program and how Dart fits into that.
Well, thank you, Karen.
We, in the planetary defense program at NASA are very excited
to be at this point in preparing for the Dart launch.
It's been a few years in development and
we're really looking forward to getting it into space.
We, in the Planetary Defense Coordination Office at NASA, oversee
the strategy that we have for planetary defense, and it has several
sectors, the first of which, of course, is the most important one.
And that's we got to find him first.
Our capabilities to search, detect and track
these objects and determine their orbits to see if any of them really are a hazard
to the Earth.
It's very rare for an asteroid to impact the Earth, but
it's something we want to know about well ahead of time.
So we're out there searching the skies, developing the catalog
of all the asteroids and comets that can come near Earth.
The second big portion of our work
is then characterizing those objects, determining what their sizes are.
Most of them are so small that if they even if they were to impact
the Earth, they would disintegrate in Earth's atmosphere.
But others are much larger, like Didymos.
Now we've been tracking and characterizing did a and its moon for for many years,
so we have a good understanding of what this asteroid system is.
Then we spend a good deal of effort
planning and coordinating with other agencies in the U.S.
government and our international collaborators in space agencies
around the world on what would be the response
if we were to find an object that was on the impact trajectory
with the Earth and and planning with them
what we might do and and what who is going to do what?
As far as response to an impact threat,
then the action then is of course mitigating.
Hopefully, we are able to do that well out into space before the asteroid
is in imminent danger of impacting the Earth.
And that's what art is all about the test of a capability
to deflect an asteroid.
All of this is part of the National near-Earth Object Preparedness
Strategy and a plan that was developed over the course of four or five years
and released in 2018 with these five goals that you see here.
So ghost goal free
testing, any old deflection
and disruptive eruption and mitigation capabilities.
That's what Dart is all about.
Our first test of a capability to do this.
And so with that, let's hear more about Dart.
Fantastic. Thank you. Lindsey Lindley.
Sorry.
Next up, we have Nancy, who is going to talk us
through the Dart mission specifically.
Great, thank you so much.
I wanted to talk a little bit
about why these asteroids were chosen for the Dart mission.
first and foremost are these asteroids are not a threat to the Earth,
they're not a danger to the Earth.
They're not on a path to hit the Earth in the foreseeable future
that makes them appropriate target for a first test.
But what really makes these asteroids ideal for
this first test is because it's a double asteroid system.
Just like the name of the mission says there's two asteroids here.
There's ditto most the larger one.
It's 780 meters in diameter, and it has a small moon asteroid that goes around it.
It's named amorphous.
It's 160 meters in diameter, and telescopes on
the Earth have been looking at this double asteroid system for decades.
Because of the telescopes here on the Earth, we know that the smaller
the Morpheus goes around Daedalus every eleven hours and 55 minutes,
just like clockwork, and we've been watching that for quite a while.
So what Dart is going to do is it's going to come speeding in really fast.
15,000 miles per hour.
And it's going to target onto the more Phobos, the smaller
of those two asteroids.
Now, darts also catch carrying, which a cube,
which is a cubesat, contributed by the Italian space agency.
It's kicked off ten days in advance
and it will fly by after darts collision roughly three minutes.
And it it'll take
some spectacular images of the ejecta that will talk more about later.
But now what we've done is the Dart
spacecraft is totally destroyed, which you cube is long gone.
How are we going to know how much we deflected this asteroid?
Well, we're going to use these same telescopes here on Earth
that have already been looking at this system for decades,
and they're going to turn their gaze back on this asteroid system.
So if you think about it, the Dart spacecraft, the main body of it,
is about 100 times smaller than amorphous, the asteroid that it's targeting.
So you can see
this isn't going to destroy the asteroid, it's just going to give it a small nudge.
It's actually going to deflect its path around the larger asteroid.
So we're demonstrating asteroid deflection in this double
asteroid system, and it's actually just a small nudge.
It's only going to be a change of about 1% in that orbital period.
So what was eleven hours and 55 minutes before
might be eleven hours and 45 minutes or so?
We're not sure that's one of the main measurements,
and that's the goal for the Dart mission here.
Now, Dart is all
about testing this technology, doing this for asteroid deflection
and importantly, doing this first test now before we'd need it
if there was an asteroid that was a threat to the Earth.
What you'd want to do this technique would would be many years in advance, decades
in advance, such that you would just give this asteroid a small nudge,
which would add up to a big change in its future position.
And then the asteroid in the Earth wouldn't be on a collision course.
And using this double asteroid system to develop this capability,
take this first step to being able to deflect asteroids in the future
is is a really a smart and a safe
way to do this first test.
Thank you so much, Nancy.
We are moving on to Elena Adams, who is going to walk us through the road
to getting to the asteroid.
Thank you, Karen.
So we have been developing Dart at the Johns Hopkins
Applied Physics Laboratory, or APL for short for about five years.
And since we have a lot of partners all over the world,
including the Italian space agency, who are providing us a small cubesat
that we're going to carry on top of our spacecraft,
that we're going to release about ten days prior to heading to Dimorphos.
So we've been in development for about five years.
About a month ago, we went to our launch
site at the Vandenberg Space Force Base,
where we're going to stay for another three weeks
since this is launch -20 debriefing.
We're going to stay there for another three weeks,
completing our tests, getting ready to load parameters.
We just loaded our propellant and in 20
days, we're going to liftoff on SpaceX's Falcon nine rocket.
one thing I want to say is
that we're going to be launching, you might have heard 23rd or 24th.
Well, the point is, though, is that we're launching on the 23rd in Pacific Time,
late in the day at 10:20 p.m..
If we launch on the first day of the launch window
or on the 24th, which is
eastern time at 120,
most of the launches are late at night, as always, just for the press.
So, so we're launching our period is actually
our launch period is actually pretty long for a planetary launch period.
It's from the November 24th all the way to February 15th,
so we could launch at any time during that time.
We will spend ten months in cruise and we will get to
Dimorphos, right, as Dimorphos is actually closest to Earth.
So we could do the observations
that Nancy just talked about using the ground based telescopes.
And we can also do other things such as stream video back to Earth of our impact.
And that's going to be pretty exciting.
So over the ten months, we're going to do a lot of different tests
using our telescope called Draco calibrated.
Make sure that it all works.
Also demonstrate some new technologies for NASA's, such as the next ion thruster,
which are shown right here, a glowing blue and
and also the rollout solar arrays,
as we said, about ten days prior to arrival at Dimorphos.
So we're going to let go of that LICIA Cube and LICIA Cube
your cube is going to follow us in. Now about four hours in before we hit.
We're going to turn on the smart nav technology,
and that is one of our new technology that we're demonstrating pronouncer
that actually allows us to guide ourselves into the asteroid
because we don't see Dimorphos at all until about an hour in,
at which point we will stop tracking
Didymos, which is the larger asteroid, and we switch over to Dimorphos
and it becomes, you know, it's just the little pixel in our camera.
And the whole time the spacecraft does everything autonomously just follows in.
And then we head and then that's it.
That's dark.
And then telescopes come
and then we make impacts that are, tell us about that is Andy Cheng.
What happens when we actually get to the asteroid?
Yeah, thank you.
the DART mission is about demonstrating deflection
of an asteroid, changing its course and doing it by
hitting it with the spacecraft so it has to hit the spacecraft.
The Dart spacecraft has to hit the asteroid,
then Dart has to measure the amount of deflection,
and then we want to understand why that deflection came about, how it works.
So it's all about measuring the momentum transfer.
How much momentum do we put into the asteroid
by hitting it with the Dart spacecraft?
And if one day an asteroid is discovered
on a collision course with Earth,
then we have an idea of how big the asteroid is
and how fast is coming and when it will hit that kind of information,
then we will have an idea how much momentum
we need to make that asteroid missed the Earth.
And so if you want to do that with the kinetic impactor, we also need to know
how much momentum does a kinetic impactor
put into an asteroid.
So that's what thermal.
That's what Dart will tell us for the dart impact.
And to do that, we're going to be measuring.
In addition to the telescopic measurements of the orbit period change
of the Didymos system, we're going to be measuring with the cameras
as we come into the target where we hit.
What are the impact conditions?
So what kind of terrain is it sloping or their boulders nearby?
What kind of terrain we hit?
And then finally, we'll have like a cube.
Take take pictures of the impact
and to measure the impact ejecta so that cube is released by Dart.
It's just a little guy.
It's a briefcase size asteroid.
It'll fly by the most on its own and then it will turn around
and we'll take pictures of the dart impact of the ejecta.
We need to do this because
the dart impact at 15,000 miles
per hour, that's going to blast tons of material,
many tons of material off the more, maybe thousands of tons.
And we need to know
how much material there is, how fast it's going
and where it's headed.
So is that information together with the information from the dart cameras?
Or where are we headed and what the impact conditions were?
That's what we'll use to determine the momentum
transfer from the dart impact.
So it's your cube is just such an exciting mission.
It's the first deep space mission for the Italian space agency.
What a way to start a program.
It's unbelievable.
Really exciting. Thank you.
Thank you so much.
And now we will switch to taking questions.
We will be inviting the media to ask questions on the line,
and we are also taking our social media questions with hashtag Ask Nasser.
So with that, I'm going to pass it over to our operator to tee
up the first question.
Thank you.
Well, now begin the question and answer session, if you'd like to ask
a question, please press star one on your phone and record your name
with from which you may start again.
Questions Please press our wondering about your name.
We'll take a moment.
But can you stand by?
The first question comes from Gina Caesarea with ABC News.
Your line is open.
Thank you.
So tell me why you did an app that.
So I want to repeat that it wasn't completely clear on our side
was the question why you didn't pick an asteroid that was headed towards Earth?
Correct.
The question, thank you. Great.
I think that might be a lonely question.
Sure.
I take that.
Well, we don't have an asteroid of that size thankfully headed toward Earth.
This is a test.
Nature has given us a set up where we have an asteroid
binary asteroid that's approaching close to Earth
so that we can observe from Earth based observatories.
But this is a test.
We don't want to be
in a situation where an asteroid is headed toward Earth
and then have to be testing this kind of capability.
We want to know
about both how the spacecraft works
and what the reaction will be by the asteroid, to the impact
before we ever get in a situation like that.
Thank you so much.
We will go to the second question, please.
The next question comes from Jordan Mendoza with today
when.
Look, can you hear me?
Yes, we can. OK.
So you guys said that there's no real asteroid hitting
if if there is no, I would tell you that
we quite and know what
again, I'm going to repeat it
and make sure we got it, OK, which is that if there is no current threat to Earth,
I believe the question was why are we doing tests like this?
So that correct?
And then if they're OK
and if there's any plan to do that once more with any other asteroid,
great that when we could hear thank you so much, the Lindley again.
Yeah.
Well, although there isn't a currently known asteroid
that's on a impact course with the Earth, we do
know that there is a large population of near-Earth asteroids out there.
In fact, we have over 27,000 near-Earth
asteroids in our catalog now of all sizes.
The key to planetary defense is finding them
well before they are an impact threat.
So we map out their orbits and where they're going and know
where in time they could be an impact threat to the Earth.
We can predict an impact threat to the Earth
if we know about the asteroid and have tracked it
decades in advance or know that day that it could impact the Earth
out into the future as much as 100 years into the future.
So that's really the key of planetary defense.
And the
question we're going to test this on other asteroids.
Yeah, well, we're going to
plan to do future test, but we might be testing other techniques
or other ways to possibly deflect an asteroid.
The principal with all of them is just to change
the speed, the orbital speed of the asteroid, just
just a small amount and nudges, as Nancy said,
and changing that speed
of the asteroid in its orbit that changes its orbit.
And so in the future, it won't be in the same place.
It was going to be in impact.
The Earth, it will be a mess.
Thank you.
I'm going back to the operator for our next question, please.
Thank you, our next question comes from Michael Greco with National Geographic.
Your line is open.
All right.
So much for doing that.
Um, my question is for Andy and Nancy.
And you mentioned that dark is alter the orbital period
of time by about ten minutes.
Um, what is the minimum change
to dimorphism this orbit that would be considered except for Dart?
And what are the biggest sources of uncertainty
that go into that estimate?
Let's start with Nancy.
Yeah, I can answer that one because we actually have that specific requirement.
It is 73 seconds.
So we are going to change it by at least 73 seconds.
We are all the models show that it'll be much more than that.
Some of the most uncertainty and we know this from previous missions
that have been to asteroids is asteroids are complicated.
They look different.
They've got boulders.
They've got rocky parts. They've got smooth parts.
They've got weird shapes.
All sorts of things are going on there.
And so how exactly the Dart spacecraft interacts with a real
asteroid of this size and where it hits is one of the main factors
for those models and also how that asteroids put together.
We know a lot of asteroids are maybe like rubble piles.
They're kind of things kind of put together.
So how dense and how closely packed are these materials
or how how distributed are they can also really contribute?
So it's really doing this real world test on a real asteroid
is why we need to do dart.
So a key
parameter there is how strong the asteroid is that will determine how much ejecta
you produce and also so basically what is the reaction to being hit by Dart?
Operator, I'm going back to you for the next question.
Thank you, our next question comes from Paul Gross with WDIV.
Your line is open.
Yeah, thanks very much for doing this.
Could you talk more about the ion propulsion engine, why is that so special?
Because that's going to get
the spacecraft to the asteroid and I understand that new technology.
Thank you. I think that is an Elena question.
Yeah, it is an Elena questions.
So the own propulsion engine, we're just demonstrating for NASA,
it is not actually our means of propulsion to the asteroid.
What we're going to do is we're going to use the typical hydrazine thrusters.
They're one Newton thrusters.
We have twelve of them scattered around the spacecraft
and we're going to use those to perform most of our trajectory.
Correction maneuvers of the EP thruster, the electric propulsion thruster.
We're going to turn on a couple of times during cruise
and we're going to just basically demonstrate that we can operate it
in space because part of the wonders
of new technology is just that step from when you build it up
to getting into space and getting it to operate for the first time.
So that's what we're demonstrating for NASA.
Thank you.
We will have that social media question now, Jason, for a check from Twitter asks
what factors were in consideration
when choosing Dimorphos as the target for the first Dart mission?
And were there other asteroids that were potential candidates?
I mean, Nancy and then Lindley,
if you want to weigh into anything. I think it's Andy and me.
Oh, right, OK.
Yeah. OK.
The Dimorphos and Didymos was always our best target.
The reasons being this binary system is such
that the
this binary system is such that the two bodies are eclipsing,
which means that they move in front of each other as seen from Earth.
And that's what makes it very easy to measure the orbit period and also
a small change in the orbit period that would be caused by the dart impact.
And there are we, we both we and also our collaborators in Europe.
We spent years looking for other possible
targets to do this mission.
This type of
demonstration?
Yeah.
So the binary system changing over a period and there really is
not another good target anywhere near as good as the Morpheus.
So and and dynamos, because of how close it is,
how readily observable, how long has been observed
also in the past all of these reasons, that's why demographers did about this.
But that started.
Yeah.
And just to add to Andy's point, also, we the other thing we've really considered
is that a this asteroid has to be fairly close to Earth at its point,
so we can stream data back to Earth before we hit.
And the other piece of the information that went in was that when we approach it,
it has to be at such an angle that it gets lit by the Sun
because we won't see if it's the asteroids really dark.
We won't be able to see it and won't be able to hit using smart navigation.
Thank you.
We're going to go
back to our media questions now, so, operator, I'm talking to you.
Thank you.
The next question comes from Megan Bartels of Space.com.
Your line is open.
Hey, there.
Thanks so much for taking my question.
I have a couple of very short questions.
Um, one is the final mission price.
one is the launch window is instantaneous for a certain period.
How long?
And then the other is if there are any post-launch milestones
that we should be looking out for before. Yes.
Right? Yes.
Thank you.
Well, I'll take the first question.
The total mission price
cost the lifecycle cost
for this mission dart mission from the time
it went into its formulation,
you know, concept development formulation
through the launch and launch vehicle,
the almost year of operations
and then the following year of of observations
and analysis of the data, which won't be until 2023.
The total lifecycle cost is of 330 million.
The if you remind me of the second question,
yeah, Megan, grab those to make sure do you want to repeat it or you?
So the second question, I believe, was they said an instantaneous launch window.
And the answer is yes.
Every day we have one opportunity to launch.
If we go in that second, we go.
If we don't, we go next day at the same time and we do that
for up to 84 times if we really wanted to.
I hope we go in the first one and then I believe the second question
is other other milestones we should look for after
after launch.
And there are a couple of things.
The first 30 days of the commissioning period,
there were going to be firing up our next engine about 20 days into it.
So I think that that would be one of the milestones
that we're going to open the Draco doors, which is our instrument.
We're going to open the door and take the first pictures
about eight days in and then, of course,
a 30 days before we hit.
We will see Didymos for the first time.
So these are the just the variety of milestones that we're going
to experience along the way.
Thanks.
We are ready for the next question.
Thank you, are not question comes from Mike Parrow
with Aviation Week and space technology.
Your line is open.
Thank you.
You may have answered this, but I just wondered how long the observations
post impact will continue to give you
the database you're looking for.
Andy, please, you know, the observations would continue
into the early spring of 2023,
so February March.
This is a telescopic observations
of the Didymos system.
Great, thank you.
We can move on to the next question.
The next question
from Marcia Smith, the space policy online icon.
Your line is open.
Like much, I was wondering in the previous
discussion, you were talking about how different rates are from each other
and of course, the very unique spacecraft, when you're taking that measurement
momentum transfer, it is like a very big data.
And I'm wondering extensible, it's going to be to the universe asteroids.
And is this
one of the more common type vast areas that might be headed towards Earth?
Or how much is this really going to help everybody
deflect asteroids in the future?
It seems like it's just one data point from one spacecraft,
which is one very unique asteroid.
Is that a Nancy question, I think it might be.
All right.
So what we do know about the dinner
most amorphous system is from spectral observations of telescopes of dynamos.
And it actually is an asteroid type that is the most common type of asteroid
out there in the near-Earth object population.
It's like ordinary conjugate meteorites.
We have samples that we've looked at here in the lab,
and it's a fine grained mixtures of rock and metal.
Together, it's actually 4.5 billion years old.
It formed before the planets formed.
It's like the leftovers of planet formation.
So that actually makes this asteroid system a really good test
in order to do this as well.
Every asteroid is going to be a little different, just like rocks
are a little different, but they share a lot of common characteristics as well.
So when we do this test on this common type of asteroid,
then it will be applicable to understanding these larger populations.
And really, it's important to take this first step in order to do this
first test so that we can develop capabilities going forward.
If I can add to that for
just a second, the size of the moon Dimorphos
hundred and 60 meters, and the smaller the asteroid is,
the more frequently it could be a impact threat to the Earth.
You know, there's many more smaller ones out there than there are large ones.
So testing against such a small
body is a challenge
with the smart nav and hitting that smaller target that far away in space.
So it's a it's a good test from that standpoint as well.
All right,
we will go on to the next question, please.
The next question comes from Devon,
cold away with Tech Crunch, your line is open.
Hi there.
Thanks for taking the questions.
I realize the data for this is meant to come out of this mission,
but do you believe there's some kind of Goldilocks zone
for intercepting incoming asteroids where it's close enough?
You can be sure we can predict its motion and hit it far enough
that minimal impact you can make is enough to deflect sufficiently.
Well, maybe our start
and maybe Andy will want to
chime in at the right time
to deflect an asteroid is as far away from space,
far away from the Earth as we can,
you know, as I mentioned earlier on.
The strategy is to find these objects not only years but decades
before they're any kind of an impact hazard to the Earth.
So we have time to characterize them first to know
where they're going to be headed, know what their size and composition is,
and know what would be the most effective method to then change its orbit.
But once we know that and have confirmed that it really is
an impact threat, you know then is the time we want to take it.
Because the further away in space it is years
before the impact, the less force it takes to change the orbit enough
that it will be a mess instead of a hit. All.
All right.
We will move on to another social media question now
recovered on Twitter asks, given that the gravity fields for did
Didymos and Dimorphos affect and are affected by each other's fields?
What post amorphous impact predictions are there, if any,
for changes in the orbit for Didymos?
Andy, please?
Yeah.
OK, so it is correct that that Dimporphos and Didymos
are gravitationally bound to each other, so they're orbiting each other.
And so that when it hits Dimorphos and changes
its motion, there's also going to be a tug on the remote.
So the whole system
will have its heliocentric orbit change, but only by a tiny amount.
That's because Morpheus is so tiny compared to did determines
the change in the Dynamo.
This orbit, in fact, is we've studied this and analyzed that
it's so
small that in fact it could not be measured easily
and it is much less even than our.
Even our knowledge of where to the most is the current knowledge of where it is
most. This is actually much
coarser than the expected change, even under the most optimistic assumptions.
The change in the orbit that would be caused by the dart impact,
it's just too tired to be measured.
So it's a very safe experiment.
Thank you so much.
We will move back to the media.
So, operator, I'm passing to you for the next question.
Thank you.
The next question comes from remains get out with Wired magazine.
Your line is open.
Hi, thank you.
I just wanted to add.
How did you?
Can you explain what angle will hit the Moon?
What like is it going to be parallel with a particular event and what?
Why do you want to get in a accurate?
Let me go to Elena.
So, you know, it is a good question,
but it is a funny question because we can't really predict
the angle of impact on to do more for us that well, we know where,
how are we going to hit in the trajectory right where we're hitting it head on?
And we know where the Sun is going to be at the time.
But the problem is that we cannot predict whether there's going to be a boulder
or something.
So our impact angle on plane off
Dimorphos is really uncertain right now, and it's really going to depend on
what demographers actually looks like, and we're not going to find that out
until the last.
Well, let's let's be honest, last 20 seconds when we're about to hit.
So we have done a lot of simulations on the ground
showing, you know, looking at all different angles of impact
to make sure that we can still transfer enough momentum into the body of dwarfs
and still are able to exact the change of at least 73 seconds.
And the answer is that our lowest numbers come back.
Something like three minutes, three to ten minutes is a range
and we're looking across all the different angles. So
and I guess I'll just add to that too.
We are purposely targeting the Moon as it comes out
from behind the other one to hit it as head on as possible.
And this is going to give you the biggest deflection, right?
And it's about 17 degrees out of the orbital debris,
the orbital plane that it's coming in.
So the local geometry, exactly like Lena was just saying, is,
you know, it's going to be a big factor and then we have to do this.
But we are targeting to be as nearly head on as possible
because the biggest deflection in the system and nearly as center
as possible, as well as possible using smart nav.
Exactly. It's going to be great. Yeah.
But it's going to depend on the lightning of the Moon as well.
Yeah,
it's a good question.
Thank you.
The other thing is also when you hit in that geometry,
the two moons are separated by about as much as possible.
All right.
Back to the media for our next question, please.
Thank you.
As a reminder, if you'd like to ask a question, please
press star one and record your name when prompted.
The next question comes from Morgan Mick Paul Johnson with Insider.
Your line is open.
All right, thanks so much.
Can you just talk about strategy once dirt is over,
how do you get to the point where you're prepared to effectively use this
method on an actual has been asteroid?
You need to follow up and doing a mission like this one eventually.
And as a follow up is the kind of thing where you build a dart like this craft
and have it on standby, or do you have to build a spacecraft
once you discover a particular hazardous asteroid?
And how long do you think that would make you past a Lindley?
Yeah, I'll take that.
Well, this test is to demonstrate that this technology is mature enough
so that it would be ready
if a actual
asteroid impact threat was discovered.
So after this mission, and we've we've analyzed it.
Assuming we don't have any major surprises, of course we
we think that this technique would be
then available would be a part of the toolbox
that we're starting to build of capabilities
to deflect an asteroid and studying all the different kinds of scenarios.
We could be faced with the orbits
of these bodies, the time
that they could be discovered ahead of the impact,
the velocities that they may have.
We know that we need a toolbox that capabilities know one technique,
you know, just kinetic impactor may not be applicable in all the situations.
So after we do this test for kinetic impactor,
we're one or two test of other techniques like gravity tractor,
for instance, Gravity Tractor is just decent people for spacecraft
off to the
side of an asteroid, and nature's tug rope
gravity will slowly pull
that asteroid off that the impending trajectory.
Other techniques, ion beam,
laser ablation.
And there are a number of good ideas out there
that we would want to look into subsequent to Dart.
But the message is that our strategy is to have a toolbox
of several different techniques.
After
a, you know, many years
of testing different things, you know, luckily
asteroid impacts don't happen all that often.
And so we're think we're have time
to do these kinds of things, and we never know what the technology
may be in the future
when we are actually faced with an asteroid impact
that we might have tractor beams and other
types of technology that would be more appropriate at that time.
This is just a start.
And when can I jump in and just say a couple of things?
Also, because Dart is demonstrating some of the other technologies, things
like the next T ion engine, for example, is a good way
of getting to a variety of asteroids
because you are providing a lot of really low thrust to the spacecraft.
So you can actually maneuver around asteroids much more easily than you would
with a traditional system where you're burning through
a lot of propellant and you're using less propellant for that.
So these are the type of things that you we are actually demonstrated
that might come in handy in getting to a variety of different asteroids,
no matter where they are.
Thank you so much.
We are going to go back to a social media question now.
Nicole Choi from Twitter asks How will Dart find and hit the asteroid
Elena?
Good question.
Thank you, Nicole.
So we are going to be using optical navigation
for a portion of the cruise of where we use our telescope called Draco,
and this telescope is going to be searching for did almost the whole time.
We are in space.
We're really in for real,
starting about 40 days out before we impact.
So right now, we have a pretty good understanding of where Dittemore system
is. And so when the spacecraft of gets launched, the rocket
puts it on a particular trajectory to go to Didymos
And in fact, if everything went well, if we're on a perfect
trajectory, we wouldn't have to do any maneuvers at all.
So we're going on our trajectory and about 40 to 30 days out,
we're going to start searching for Didymos where we expect it to be.
And the whole time,
you know, 40 days out to about ten days
out, we are taking images every five hours
and we're processing them on the ground here with the navigation team at JPL,
who is actually processing images
and making sure that we're navigating towards Didymos correctly.
And we are still navigating
to dilemmas all the way in through four hours in
at which point the spacecraft starts navigating itself.
And at that point,
it keeps navigating
itself to Didymos until about an hour out of which point to switch to switch.
It finds Dimorphos because, as Andy said, the Moon will come out
from behind Didymos.
It finds the Dimorphos and then it navigates the words itself, Dimorphos.
But the whole time is just based on the fact that we're taking pictures
and we know where it is.
We're going to go back to the media now.
Operator, do we have the next question?
Yes, our next question comes from Paul Brinkman with UPI.
Your line is open.
Hi, yeah, thank you very much.
Can you hear me? Yes, we can.
Great.
one quick question about the impact timeline.
The mission website is September 26 to October first.
How does that change if the launch date is delayed?
And then I also wanted to know, I guess, it was going to be
secondary operation by radio telescope
or Deebo was part of that plan.
Can you just explain what, if any, impact collapsed
various people had on that plan? Thanks.
Thank you, Alina.
The first half of the question, then I will throw it over to Nancy.
Yes, it sounds good.
So the reason why it says September
26 through October first is it all depends on when we launch in the launch period .
As I said earlier, we have 84 opportunities.
If we launch on day one of our of our opportunity,
we will hit Dimorphos on September 26.
And basically, as we go farther in the launch period
by February 15th, where you're hitting it on October first,
that constraint was really placed there just for the radar observations
to so that way, the radar can actually see when Dimorphism is closest to Earth.
So lending over to you. Mm-Hmm.
said earlier, the real measurement of the change
in the orbit orbital period of Dimorphos,
what we've done with optical telescopes, it's done
by observing the light curve
brightness and dimming of this eclipsing binary
when the moon goes in front and behind the primary object.
So radar was never
a prime requirement for the mission.
That being said, it's always good to get the radar observations
because they provide very precise positioning.
And if the signal is strong enough,
you know, actual imaging of at least the main body
and maybe the position of the Moon, a moon that small that far away
over 6 million miles is still hard to detect with our planetary radar.
Yeah, we we still grieves
the loss of the irascible radar,
but we still have a Goldstone 70 meter Goldstone
Solar System radar capability
and the we do plan
to observe using Goldstone.
And if the setup is right, we're used the Goldstone
to transmit the 70 meter to transmit and or receive the signal
at the Green Bank Observatory in West Virginia.
That set up
by static radar set up gives us the strongest
signal to noise ratio and
would provide the best observations
in this particular situation.
And we'll take the next media question, please.
Thank you.
As a reminder,
if you'd like to ask a question, please press star one and record your name.
The next question comes from Michael Greco with National Geographic.
Your line is open.
How much?
two quick questions, I think the first might be
for Nancy and Andy, the second is for Windley.
There's there's been some questions about
the long term characterization of darts.
I was wondering if you could speak to how important
the European Space Agency's upcoming Harrah mission
will be to understand the long term impact of the Dart and then Lindley.
You mentioned earlier the importance of detecting these asteroid
as soon as possible.
Earlier today, the Asteroid 2020 decadal survey was published, and it noted
satellite constellations biggest potential scientific impact on astronomy
would come into play in the discovery of near-Earth objects.
So I was wondering if you could speak to kind of the long term plan for
observing and detecting near-Earth objects and the potential effects of things
like megaconstellation? Thanks.
We will go to Andy for the first question and Lindley for the second.
OK? OK, so the European Harrah mission will
launch in 2024 and will visit
Didymos system in late 2026
and make very important contributions
to understanding the outcome of the dart impact.
So there's two main things that we do.
The first is the spacecraft, the European spacecraft.
Hera will directly measure the mass of the Morpho,
so that's a measurement that cannot make all by itself.
We can make estimates, but there will be a direct measurement
of the mass from hedgerows
in rendezvous with the identical system.
And the second important measurement they'll make is they'll be able to study
the impact crater that the dart impact made.
How big is it, how deep is it?
And maybe even look for pieces
of the Dart spacecraft that may be sticking out of the ground?
Who knows?
OK, well, the second part of that
was what's going to be the impact of these mega constellations
that are being talked about as 30,000, you know, spacecraft, something like that
to to these surveys of ground based surveys.
The first thing is that, well, you know, the current surveys are
spacecraft up there now, satellites, debris, and it is something
that we have to contend with with our imagery from the ground already.
But with that size, the constellation
of the dugong doing some estimating
and some of our survey systems, the number of times
that one of those spacecraft would be in the field of view.
And you've got that many up there and just about every image that we would take
would have one of those spacecraft in it.
And so part of the image now these are very wide field images,
so only a part of the image would be
damaged, so to
speak, by the that satellite being in it.
But it wouldn't completely
disable the capability.
But our real direction
for the neo program is our next mission
that is under the formulation right now into preliminary design.
And that is the near-Earth Object Surveyor,
which is a space based air infrared telescope that's being specifically
designed to detect, track and characterize near-Earth asteroids.
It will be launched and positioned into space
at the Earth Sun L1 point to about 1,000,000 miles or sunward,
and that'll be well away from Earth
and won't be affected by these constellations.
But it's, you know, it's still a area of concern
because a lot of our characterization observations and certainly
a lot in the astrophysical realm are that still use.
The ground based observatories
are concerned about the number of spacecraft that are up there
and what effect they could have on the imaging from ground based telescopes.
Thank you so much.
We are going to take another social media question now,
Steve from Facebook asks What is smart nav and how does it work?
I think that's for Elaina.
Thank you, Steve.
All right.
So smart nav is a set of algorithms
that we use in order to be able to find and head to Morpheus.
And these algorithms come from the development
for many years at the Applied Physics Laboratory for Missile Defense,
where they also look for really small things and they try to hit them.
But in this case of, we're using it for planetary defense,
and it's a set of algorithms that control our thrusters, which are a
main way to propel our spacecraft.
They control our attitude to make sure that we can actually point
our imager at the asteroid.
So we're pointing our imager at amorphous.
We're taking pictures and those pictures add up and the spacecraft
and their process to see if we can form a track to that asteroid.
You know, we basically are taking out the attitude motion of the spacecraft,
and we're trying to see if we can keep tracking that one dot
that we think is the asteroid.
And that's how it basically works.
At some point, it switches over to
Dimporphos from Didymos and does the same thing the whole time.
It's trying to correct its attitude and correct its trajectory,
you know, so its center sits itself in space and figures out, Where am I?
Where do I need to go in order to be able to have to really directly hit this dock?
The main thing it has to take into account orbital emotion
to add and conditioned to just the linear flight.
That's right.
The fact that the dimorphic is not just going back and forth
and you're seeing a 2D image of it, right?
That adds up as well.
As well as start popping in and out of the field of view of the star
striker know it's a little bit more complicated, but that's the basics.
Thank you so much.
We will go back to a media question now, please.
Thank you, the next question comes from Megan Bartels with Space.com.
Your line is open.
Thanks so much.
This might be sort of a basic orbital thing,
but could you explain why if you hit the moon head on,
it will eat up the orbit right now?
All right, we'll pass to Andy for that one. OK.
Yes. When we hit.
Demographers head on instantaneously, you are slowing down the moon in its orbit,
but because it's slowing down, what happens is that the centrifugal force
that's holding the Moon away from did most gravity.
The centrifugal force is reduced, and so the moon falls closer to Didymos.
When it falls in closer, it speeds up.
This is the same process as the skater
who is turning pulling in her arms and she spins out faster.
It conserves the angular momentum, so the same process
Dimorphos come in swinging and closer to the main body.
It has to speed up to conserve angular momentum.
Of course, when it goes, it backed out again in its orbit.
It slows down again,
but the speeding up is more than the slowing down.
And on the average, the orbit period is shortened.
On the average, the orbit speed increases.
So that's what happens even though we hit it head on and instantaneously
slow down the target.
Thank you.
The next media question, please.
Next question comes from Marcia Smith
with space policy online dot com, your line is open.
Thanks so much for letting me ask a second question.
Someone brought up earlier about how the kale survey is out-of-date,
and it makes me wonder about planetary science decadal that's underway.
Are they evaluating planetary defense missions and
how you should prioritize the type of techniques
that you have know apart from kinetic impact and help you
prioritize where you should be investing your money for future missions?
And if that's not part of the title, is there some other group
then the academies or somewhere else that helps you prioritize
whether to invest in these kinds of missions or invest in AI?
Is it Neo assume that the survey mission
or ground-based, uh, identification of asteroid?
How do you support all that out that excites you?
Well, we happen to have the perfect person to answer that question
here, and that is Nancy.
But that's not the intro that I was expecting there.
Lindley.
Yeah, I'm a I'm serving as the chair of the Small Bodies panel
for the Planetary Decadal Survey that's currently ongoing.
We've had a number of open sessions and you can check out the website for there.
But yeah, planetary defense
is within the scope of the Planetary Decadal Survey for the first time.
So this next planetary decadal survey that comes out will include a discussion
of planetary defense and priorities looking forward for the next decade.
Obviously, that's not scheduled to come out until next March,
so I really don't have a whole lot more to say about that.
But if you want to add on to that Lindley, I think it's really great
that planetary defense is being included in the Cato survey for this time.
Yeah, it is.
And it signifies that, you know, the planetary defense program is
a important part of the overall planetary science
portfolio at NASA now.
We do have one last social media question,
I think if we answer it quickly, we can fit it in before we have to go.
Sharon on Twitter asks Do we already know what kind of surfaced
Dimorphos has and if it turns out to be a porous surface?
Would the redirection still be effective?
OK, do we already know what kind of service tomorrow says the answer is no.
Simple as that, we know nothing about it.
It's just barely resolved,
even in the radar data.
And while the redirection still be effective, yes, we believe so.
The amount of deflection we get is uncertain.
Porosity affects that, but there will be a redirection.
We are confident of that.
Thank you so much.
Thank you to all of our speakers for being here today.
Thank you so much for joining us.
Keep watching nasa.gov
live for that launch coming up later this month.
And in the meantime, thank you.
Goodbye.