Donald Savage

Headquarters, Washington, DC

(Phone: 202/358-1547)

RELEASE: 00-119

In 2003, NASA plans to launch a relative of the now-famous
1997 Mars Pathfinder rover. Using drop, bounce, and roll
technology, this larger cousin is expected to reach the surface of
the Red Planet in January, 2004 and begin the longest journey of
scientific exploration ever undertaken across the surface of that
alien world.

Dr. Edward Weiler, Associate Administrator, Office of Space
Science, NASA Headquarters, Washington, DC., announced today that
the Mars Rover was his choice from two mission options which had
been under study since March.

“Today I am announcing that we have selected the Mars
Exploration Program Rover rather than the orbiter option, which was
an extremely difficult decision to make,” said Weiler. “At the same
time, we want to look into what could be an amazing opportunity, as
well as a challenge, by sending two such rovers to two very
different locations on Mars in 2003 rather than just one.”

“We are evaluating the implications of a two-rover option,
Weiler added. “I intend to make a decision in the next few weeks so
that, if the decision is to proceed with two rovers, we can meet
the development schedule for a 2003 launch.”

With far greater mobility and scientific capability than the
1997 Mars Pathfinder Sojourner rover, this new robotic explorer
will be able to trek up to110 yards (100 meters) across the surface
each Martian day, which is 24 hrs. 37 min. The Mars rover will
carry a sophisticated set of instruments that will allow it to
search for evidence of liquid water that may have been present in
the planet1s past, as well as study the geologic building blocks on
the surface.

“This mission will give us the first ever robot field
geologist on Mars. It not only has the potential for breakthrough
scientific discoveries, but also gives us necessary experience in
full-scale surface science operations which will benefit all future
missions,” said Scott Hubbard, Mars Program Director at NASA
Headquarters. “A landed mission in 2003 also allows us to take
advantage of a very favorable alignment between Earth and Mars.”

After launch on top a Delta II rocket, and a cruise of seven
and a half months, the spacecraft should enter the Martian
atmosphere January 20, 2004. In a landing similar to that of the
Pathfinder spacecraft, a parachute will deploy to slow the
spacecraft down, and airbags will inflate to cushion the landing.
Upon reaching the surface the spacecraft will bounce about a dozen
times and could roll as far as a half-mile (about one kilometer).
When it comes to a stop, the airbags will deflate and retract, and
the petals will open, bringing the lander to an upright position
and revealing the rover.

Where the Pathfinder mission consisted of a lander, with
science instruments and camera, as well as the small Sojourner
rover, the Mars 2003 mission features a design that is dramatically
different. This new spacecraft will consist entirely of the large,
long-range rover, which comes to the surface inside a Pathfinder
landing system, making it essentially a mobile scientific lander.

Immediately after touchdown, the rover is expected to give us
a virtual tour of the landing site by sending back a high
resolution 360-degree, panoramic, color and infrared image. It will
then leave the petal structure behind, driving off as scientists
command the vehicle to go to rock and soil targets of interest.

This rover will be able to travel almost as far in one Martian
day as the Sojourner rover did over its entire lifetime. Rocks and
soils will be analyzed with a set of five instruments. A special
tool called the 3RAT,2 or Rock Abrasion Tool, will also be used to
expose fresh rock surfaces for study.

The rover will weigh about 300 pounds (nearly 150 kilograms)
and has a range of up to about 110 yards (100 meters) per sol, or
Martian day. Surface operations will last for at least 90 sols,
extending to late April 2004, but could continue longer, depending
on the health of the rover.

“By studying a diverse array of martian materials, including
the interiors of rocks, the instruments aboard the Rover will
reveal the secrets of past martian environments, possibly providing
new perspectives on where to focus the quest for signs of past
life,” said Dr. Jim Garvin, NASA Mars Program Scientist at NASA
Headquarters. “Furthermore, the Rover offers never-before-possible
opportunities for discoveries about the martian surface at scales
ranging from microscopic to that of gigantic boulders. This is a
key stepping stone to the future of our Mars exploration program.”

One aspect of the Mars Rover’s mission is to determine history
of climate and water at a site or sites on Mars where conditions
may once have been warmer and wetter and thus potentially favorable
to life as we know it here on Earth.

The exact landing site has not yet been chosen, but is likely
to be a location such as a former lakebed or channel deposit – a
place where scientists believe there was once water. A site will be
selected on the basis of intensive study of orbital data collected
by the Mars Global Surveyor spacecraft, as well as the Mars 2001
orbiter, and other missions.

The alternative mission, which had been under consideration
for the 2003 opportunity, was a Mars scientific orbiter, which
featured a camera capable of imaging objects as small as about two
feet (60 cm) across, an imaging spectrometer designed to search for
mineralogical evidence of the role of ancient water in martian
history, and other science objectives.

Teams at NASA’s Jet Propulsion Laboratory (JPL), Pasadena, CA,
and Lockheed Martin Astronautics, Denver, CO, conducted separate,
intensive, two-month studies of the missions.

“Both teams did an absolutely superb job in preparing these
proposals in a very compressed time frame,” said Dr. Weiler. “They
both deserve a lot of credit for what they were able to achieve.”

“This project can be accommodated within the President’s
budget request for NASA and we will spend the next few weeks
refining our budget estimates and other requirements, plus the
impacts and the consequences of sending two rovers to Mars instead
of one,” said Hubbard. “When we have fully addressed all of the
issues, which may take several weeks, we will announce our final

– end –