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[Music]

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[Title: Dusk for Dawn NASA
Mission to the Asteroid Belt]

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[Marc Rayman] You know,
when you work

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on a mission this long

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it feels like a part of you.

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I've been a space enthusiast
since I was four years old.

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Getting to work on a
mission like this is...

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...it's a dream come true.

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To me, Dawn is truly Earth's
first interplanetary spaceship.

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No other spacecraft has
gone to a distant body,

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gone into orbit around it,

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maneuvered there,

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then broken out of orbit,

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traveled elsewhere in
the solar system

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to another alien world and
going into orbit around it.

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And it does that
with ion propulsion

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which I first heard of
on a Star Trek episode.

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We've turned ion propulsion

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from science fiction
into science fact.

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[Carol Raymond] The Dawn mission

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really is a journey back to the
beginning of the solar system.

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That's why we call it Dawn.

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We chose two time capsules

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from the beginning
of the solar system,

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Vesta and Ceres,

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which are the most massive

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and largest bodies in
the main asteroid belt.

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They both formed very early when
the solar system was forming

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out of the protoplanetary disk

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and yet they ended up in these
two very different states.

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Vesta is a dry, rocky body that
looks a lot like our moon.

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Whereas Ceres had a lot of
water and it looks much more

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like the icy moons of the
outer solar system.

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[Rayman] And it seems like
what determined their

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eventual fate was the location
where they started.

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And we now believe
that Ceres formed

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much farther from the
sun than it is now.

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[Raymond] When Dawn found the
bright material on Ceres,

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what we saw was
completely mind blowing.

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It was made of
sodium carbonate.

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Sodium carbonate is not
common in the solar system

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but we see it coming
out of the plumes of Enceladus,

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we see it in lakes on Earth,

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and here it was on
the surface of Ceres.

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[Rayman] The mission will end
when Dawn runs out of

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the conventional chemical
propellant that it uses

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to orient itself in the
zero gravity of space.

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Dawn will become this inert
celestial monument

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in orbit around the dwarf
planet that it unveiled.

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Dawn serves a lasting
reminder that the passion

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for bold adventures

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and our noble aspirations to
reach out into the cosmos

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take us far far
beyond the confines

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of our humble home
here on planet Earth.

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[Text] The Dawn spacecraft has
operated for 11 years,

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three years longer than
originally planned.

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[Text] When its hydrazine fuel
runs out in late 2018,

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the spacecraft will no longer
communicate with Earth.

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[LOGO: NASA / Jet
Propulsion Laboratory