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- Hi, I'm Doctor Ellen Stofan,
also known as Doctor E.
- And I'm Thomas Zurbuchen,
also known as Doctor Z.
- And we're here for another
episode of E.Z. Science.
Today, we're at the Steven
F. Udvar-Hazy Center
in Chantilly, Virginia,
which is the other part
of the National Air and Space Museum.
And this is one of my
favorite places because
we have things like the
Space Shuttle Discovery.
But we also have this exhibit,
which has one of my favorite Mars landers.
Thomas, do you know which lander this is?
- Yeah, it's Sojourner, you know,
I remember it from The Martian.
- Pathfinder, with a
little Sojourner rover
landed in 1997 on the surface of Mars.
The stuff you see laying
around the ground here
is actually an airbag
that helped it land safely
on the surface.
It literally landed like a bouncing ball.
The airbag deflated and
then it could deploy
the solar panels and then
this little Sojourner Rover
could come out and down onto the surface.
- The most exciting part, right,
is to actually land there
with something that can roll off.
- So this robotic mobility
really set a path,
literally, with Pathfinder and Sojourner
to how we explore Mars today.
It was followed by the
Spirit and Opportunity Rover
and the Curiosity Rover.
Because we realized, to really
explore the geology of Mars,
we needed to get out
there and move around.
Just landing in one
spot wasn't good enough.
- What's so amazing to
me is how light it is.
It's only 23 pounds, this entire vehicle.
- Yeah and actually, this
mission really gave us
some breakthrough science about Mars.
We had known from orbital data that Mars
had these huge channels carved into it
that we thought were carved by water.
But Pathfinder and the Sojourner Rover
really gave us the first evidence that
the rocks at the surface
showed a lot of signs of
having been laid down
and modified by water.
That gives you the knowledge
that it wasn't just
an instant in time of water,
that the water had to have persisted
for tens of millions of years,
if not hundreds of millions of years.
- And of course it's that very insight
that really has clarified many of the
historic questions about Mars.
You know, how three and
a half billion years ago
did they become so different...
- Yeah.
- Than the earth.
We're making a mission ready right now
from 23 pounds or so of a rover
to a little bit under
twenty-five hundred pounds,
Mars 2020.
- To me, 2020 is really
this important next step
where Pathfinder and Sojourner,
Spirit and Opportunity,
Curiosity, will try and
answer the question,
could Mars have been habitable?
Were there environments on the surface
in which life could have evovled.
We know the answer to that question
because of all the work we've done
with these previous missions,
the answer to that question is yes.
- We know that where we're going to land,
at Jezero Crater, it's
basically a river delta
next to some craters, right?
An ancient river delta.
That's a place that we would wanna be
if we would want to look for extinct life
if there's such a thing.
- Mars 2020 is really
pushing that issue of
can we find evidence of past life on Mars.
- That's right.
That's why the instrumentation
is way more complex
than pretty much any of
the other instruments
that we've had there.
For example, we have
ways to really analyze
in much more detail, even the morphology,
the looks of samples before we put them
in the sample flask, hopefully
to bring them back later on.
- So if it launches in July of 2020,
when does it actually get to Mars
and when will we start
seeing that first data
after the landing?
- It's gonna be there in
February of the next year, of 21,
coming down, and pretty much within days,
we'll get the first data.
What I'm really excited about is during
entry, descent, and landing,
we have way more cameras
than we've ever had.
We're gonna see it go down,
and we're gonna see the look up too.
And of course we're also
bringing a small helicopter.
- Sojourner was
record-breaking in it's time.
This little rover that
was gonna explore Mars.
Now you're moving beyond
surface exploration
into aerial exploration
with the helicopter
technology demonstration.
- Exactly right.
Close to 500 years after the death of
Leonardo da Vinci who actually
made the first drawing
of a helicopter,
we're gonna bring such a
vehicle to a distant world.
It will be the first controlled flight
in a distant world.
- And because 2020 is so much
heavier than Pathfinder here,
we really have to use
a much more complicated
landing system.
So retrorockets fire,
parachutes come out to
slow it down as it enters the atmosphere,
but then the spacecraft
is actually lowered
to the surface on what's
called the sky crane.
And it's what the folks
out of JPL have termed,
"Seven Minutes of Terror" as it starts
from the top of the atmosphere
all the way to the surface.
- Exactly right.
It's a very tough time to sit there
until you hear from the
surface that, "I'm okay."
Risky time.
It's 50 percent or so likelihood
of success statistically
for humanity to land or go to Mars.
- Well, especially this summer,
we're gonna come back
to you on E.Z. Science
and talk more about Mars 2020
as we get close to the launch.
- Yeah, really appreciate that,
what an exciting exhibit.
An exhibit that points
forward to something
that's going to happen.
Thank you so much for
all of this discussion.
- And thanks for coming and joining us
on another episode of E.Z. Science.
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