[Music]
[Title: Dusk for Dawn NASA
Mission to the Asteroid Belt]
[Marc Rayman] You know,
when you work
on a mission this long
it feels like a part of you.
I've been a space enthusiast
since I was four years old.
Getting to work on a
mission like this is...
...it's a dream come true.
To me, Dawn is truly Earth's
first interplanetary spaceship.
No other spacecraft has
gone to a distant body,
gone into orbit around it,
maneuvered there,
then broken out of orbit,
traveled elsewhere in
the solar system
to another alien world and
going into orbit around it.
And it does that
with ion propulsion
which I first heard of
on a Star Trek episode.
We've turned ion propulsion
from science fiction
into science fact.
[Carol Raymond] The Dawn mission
really is a journey back to the
beginning of the solar system.
That's why we call it Dawn.
We chose two time capsules
from the beginning
of the solar system,
Vesta and Ceres,
which are the most massive
and largest bodies in
the main asteroid belt.
They both formed very early when
the solar system was forming
out of the protoplanetary disk
and yet they ended up in these
two very different states.
Vesta is a dry, rocky body that
looks a lot like our moon.
Whereas Ceres had a lot of
water and it looks much more
like the icy moons of the
outer solar system.
[Rayman] And it seems like
what determined their
eventual fate was the location
where they started.
And we now believe
that Ceres formed
much farther from the
sun than it is now.
[Raymond] When Dawn found the
bright material on Ceres,
what we saw was
completely mind blowing.
It was made of
sodium carbonate.
Sodium carbonate is not
common in the solar system
but we see it coming
out of the plumes of Enceladus,
we see it in lakes on Earth,
and here it was on
the surface of Ceres.
[Rayman] The mission will end
when Dawn runs out of
the conventional chemical
propellant that it uses
to orient itself in the
zero gravity of space.
Dawn will become this inert
celestial monument
in orbit around the dwarf
planet that it unveiled.
Dawn serves a lasting
reminder that the passion
for bold adventures
and our noble aspirations to
reach out into the cosmos
take us far far
beyond the confines
of our humble home
here on planet Earth.
[Text] The Dawn spacecraft has
operated for 11 years,
three years longer than
originally planned.
[Text] When its hydrazine fuel
runs out in late 2018,
the spacecraft will no longer
communicate with Earth.
[LOGO: NASA / Jet
Propulsion Laboratory
California Institute
of Technology]
