something is going to hit the earth
again there is an impact in Siberia
within the last decade that was caused
by an object about 20 metres across it
broke up in the atmosphere and created a
big shockwave it was ten times the size
of that Hiroshima nuclear explosion it
injured about a thousand people in the
town of Chelyabinsk of course if you
imagined this happening with a greater
population density the purpose of the
dark mission is to take your spacecraft
and you Ram it into an asteroid to
change the orbit so it won't hit the
earth we're not just trying to figure
out how to deal with what's coming no
we're actually going to go out there and
we're gonna try to stop it difference is
all great but you do need to score
points
earth gets hit by asteroids and small
debris all the time but most of the
asteroids break up in the atmosphere all
of the bigger asteroids have been
cataloged like the dinosaur killers that
are ten kilometers or 1 kilometers plus
at this point what we're looking for are
things that are smaller than if they
were to hit the earth they would create
a regional impact asteroid impacts that
are big enough to cause damage and cause
real problems are rare but the stakes
are really high so the problem when an
asteroid impact is that the earth is
going around the Sun an asteroid is
going around the Sun and they both want
to be in the same place at the same time
it's been over the past 20 years that
planetary defense has started to be
taken seriously after an impact into
Jupiter by a comet in the mid 90s and
this impact into Siberia I think also
opened a few more eyes in 2016 the
planetary defense coordination office
was set up in NASA to demonstrate that
we can do something about an asteroid
impact if something is coming in a
nuclear device for a long time it has
been the only tool that people
considered but the concern with
dispersing that asteroid is that now you
have 2 or 5 or 15 things and the pieces
aren't that much smaller what we want to
do is understand those orbits for all
the asteroids that might come close to
the earth and it becomes a matter of
picking the new orbit you want for the
asteroid and then changing its speed if
you have 20 or 30 years to do that then
you only need to change the speed by a
millimeter a second or less and then
it'll miss the earth entirely
the purpose of the dark mission as a
whole is to test how this technique of a
kinetic impactor would work if we ever
needed to use it to deflect an asteroid
dinner MOS is a binary asteroid system
so there's a main body and it has a
satellite we call those dinner most a
and it must be by going to a binary
asteroid system for the dart mission the
scale is much smaller
dieter mosby is moving around only at
maybe 50 centimeters a second so if you
change the speed by a millimeter a
second that is pretty easy to measure
given our capabilities awesome thing is
our dartboard
because one should have one with didymus
B on it over here which is the this is
the main asteroid and then did must be
is clearly where everybody hits says the
counting down to the 10 we started the
spacecraft int where the whole
spacecraft comes together so we're very
excited 163 days it's very short amount
of time
it's insane so dart is launching on a
SpaceX Falcon 9 rocket in July of 2021
each one of the nasa missions has you
know the main objectives so our most
important one is we direct a moon of an
asteroid our second most important one
change its rotation period by about 73
seconds our third objective is on the
ground they're going to spend some time
looking at the rotational period and are
able to figure out how much we change
the period and then our last objective
is when we're going to hit it we're
going to create a plume it's called an
ejecta and people want to be able to
measure how much that plume helps push
the moon along the way
the dark mission is a technology
demonstrator for NASA we're
demonstrating not only our first
planetary defense technique we are
demonstrating the next C ion engine
we're demonstrating the rola solar
arrays which is basically solar cells on
big blankets and they provide a lot of
power to the spacecraft and they're
super lightweight but the most important
one of course is smart nav and that's
what allows us to hit the asteroid
dinner mosby is about 160 meters so but
the size of the Washington Monument it
takes us about 12 months to get to the
asteroid we're going at about 15,000
miles an hour which means that we're
going to be going from New York to DC in
one minute as we get closer in about
eight hours out we turn on all our
systems we're starting to stream
pictures back to earth the spacecraft is
still under ground control though and at
four hours out we turn it over to the
smart navigation system all we see is
essentially one bright dot that might be
about two to three pixels large and
that's the Dynamo system all the folks
that are going to be in the Mach behind
me here
there's going to be listening they're
not doing anything else and the
spacecraft itself is going to control
what it's doing and it's going to target
the asteroid at 80 minutes out is when
did it Mosby starts hopping out from
behind
starting out at 1/2 pixels we're trying
to aim for the center but imagine a
center of a dog bone where exactly are
you trying to get to so what you're
trying to do by smart nap is trying to
create an envelope of what you think
this immune might be like even though
you don't know the shape parts of it
could be completely dark and you don't
actually see them and yet you're still
trying to go for the center it's very
hard my biggest thing is to test the
smart nerve algorithm to death we use
many different asteroid models run a
bunch of simulations and see that the
algorithm performs as we expect it to
and that it's not until about two
minutes out that we're able to
completely see the whole moon in its
field of view we have this communication
delay of about a minute and a half that
time delay for any decision-making
process for humans in the loop in real
time especially at the speeds that we're
traveling is essentially impossible and
then it's going to perform the impact
you're kind of done at the moment of
impact and if you missed it that's
really not good so yeah it's gonna be
mostly terrifying probably exciting the
reason why I think dart is so incredibly
cool compared to other science
investigation mission is that you talk
to person on the street and then you say
oh I'm working on the mission that's
going to study the solar wind and they
say what is that well but then with dart
it's a very straightforward mission you
feel like you're helping humanity as
opposed to you know saying that I'm
exploring the world around me I think if
people can go to bed sleep a little bit
easier you know without some existential
dread that tomorrow they're gonna get
blown up by an asteroid that you know we
can't do anything about then I think
that's that's good too you know if we
can lower the stress level of humankind
I think that's that's also worth
something
do you feel like you are saving the
world huh do i retain the rights to the
action figures and stuff if you liked
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