Music open.

NARRATOR:

A journey to the north pole---of Mars.

I\'m Jane Platt with a podcast from JPL -- NASA\'s Jet Propulsion
Laboratory in Pasadena, California.

A new NASA spacecraft is all dressed up -- with a really cool place to
go---literally. Phoenix Mars Lander will zoom through space and land the
middle of next year in the far north part of Mars, the polar region.
Joining us is Phoenix Project Scientist Leslie Tamppari of JPL. Welcome,
Leslie.

TAMPPARI: Thank you.

NARRATOR: Well, we already have four NASA spacecraft at Mars, including
the two very long-lived rovers, Spirit and Opportunity. And the European
Space Agency has an orbiter as well. So what is Phoenix going to add to
this mix, to the fleet?

TAMPPARI: Phoenix is going to an entirely new region that we've never
been to before. We're going to the north polar region between 65 and 72
degrees north. And we'll be able to be in the environment during
northern summer when the water icecap is completely exposed and water is
coming off the cap, and it's a great place to study the water cycle on
Mars. It\'s also a place where we have surface ice that was discovered
by the Odyssey spacecraft, and we'll sample that ice and be able to tell
something about the habitability of the environment.

NARRATOR: Again its part of the theme of following the water on Mars,
where it might have been, where it could be now and where it might be in
the future. Just a really brief, thumbnail recap of why we're so
interested in water on Mars.

TAMPPARI: Water is a big mystery on Mars. We think that there was vast
floods of water very early in Mars' history, but today we don't see
evidence for floods like that, that might happen. So we want to
understand the current climate very well so that we can understand what
the past climate might have been like. And of course water is important
for the life, so understanding where the water is and how it\'s changed
on Mars over its history is very important for understanding if life
ever could have arisen on Mars.

NARRATOR: And this particular region in the far north part of Mars
enables you to answer different questions than were possible in the
other areas, for example, where Spirit and Opportunity are.

TAMPPARI: Yes, Spirit and Opportunity are looking for evidence of
ancient water, whereas we're looking at the current water. We're looking
in an environment where in the last 50,000 to 100,000 years, the
environment has changed due to the tilt of the planet changing over that
time, and so there might have been times when liquid water could have
been standing on the surface for a period of time that might have been
conducive to life. So it's very interesting from that standpoint.

NARRATOR: So Phoenix will carry seven science instruments. Can you
explain to us what they will be able to do?

TAMPPARI: Yes, we have instruments that will be able to gather samples
from the surface and analyze those samples onboard the spacecraft. And
then we have a very rich weather station that will enable us to
understand the local weather in our landing environment. And we have a
series of cameras that will allow us to take images from before we land
the spacecraft, and view our scene before we land, all the way down to
measuring a particle that might be as small as one one-hundredth of a
hair width.

NARRATOR: And this particular mission to Mars is not landing with
airbags as Spirit and Opportunity did and as Mars Pathfinder did in
1997.

TAMPPARI: Yes, we have a power descent landing system, so we're going to
land on legs, and we have engines that will help slow us down. So
basically when we come into the atmosphere, it's very similar to all of
the previous spacecraft. We have a heat shield that protects us until we
get lower in the atmosphere, we have a parachute that deploys. All of
our previous spacecraft have used that. So it's then in that final one
kilometer or so when we have a different mechanism and that's when
we\'ll have the heat shield come off, the legs will deploy and the
engines will start and slow us down to a nice, soft landing.

NARRATOR: Actually getting to and landing on Mars is very challenging,
and it's always a real nail-biting experience.

TAMPPARI: We put a lot of effort into the entry, descent and landing,
that's about six minutes from the top of the atmosphere to the landing.
And we have a whole team of people working just specifically on that. So
we have not only a lot of effort and a lot of talented engineering going
into that, but we have a lot of reviews that help challenge us and make
sure that we've thought of all possible things that can go wrong.
However, landing on Mars is sometimes difficult and we could get
unlucky, there are things we can't control. For example, the winds, we
try our best to predict what they might be like and bound them, but we
could get unlucky. In addition, we have picked a place that we think is
very safe with respect to rocks, but still we might get unlucky and land
on the one spot where there's a big rock. So we hope not and we've
definitely tried to prevent against that to the extent possible. But it
is still a risk to land on Mars.

NARRATOR: But the rewards are great, and if all goes well, after Phoenix
what will you know that we do not know now?

TAMPPARI: Well, we hope to really understand the polar weather. We've
never had a spacecraft successfully land in either of the polar regions,
so Phoenix will be the first successful lander. And we hope to
understand the habitability of the landing site, whether or not this
location is conducive for life, should life have ever been on Mars.

NARRATOR: Thank you very much for joining us today.

TAMPPARI: Thank you.

NARRATOR: We\'ve been talking with Phoenix Mars Lander project scientist
Leslie Tamppari of JPL. More information on the mission is online at
[www.nasa.gov/phoenix](http://www.nasa.gov/phoenix) . Thanks for joining
us for this podcast from NASA\'s Jet Propulsion Laboratory.