[meteorite-list] NASA's Next Leap in Mars Exploration Nears Arrival

[Ron Baalke]

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

Guy Webster  (818) 354-6278
Jet Propulsion Laboratory, Pasadena, Calif.

Dwayne Brown  (202) 358-1726							
NASA Headquarters, Washington 						

February 24, 2006       
                                                         
News Release: 2006-026

NASA's Next Leap in Mars Exploration Nears Arrival

As it nears Mars on March 10, a NASA spacecraft designed to 
examine the red planet in unprecedented detail from low orbit 
will point its main thrusters forward, then fire them to slow 
itself enough for Mars' gravity to grab it into orbit.

Ground controllers for Mars Reconnaissance Orbiter expect a 
signal shortly after 1:24 p.m. Pacific time (4:24 p.m. Eastern 
time) that this mission-critical engine burn has begun.  However, 
the burn will end during a suspenseful half hour with the 
spacecraft behind Mars and out of radio contact.

"This mission will greatly expand our scientific understanding 
of Mars, pave the way for our next robotic missions later in 
this decade, and help us prepare for sending humans to Mars," said 
Doug McCuistion, Director of NASA's Mars Exploration Program. 
"Not only will Mars Science Laboratory's landing and research 
areas be determined by the Mars Reconnaissance Orbiter, but the 
first boots on Mars will probably get dusty at one of the many 
potential landing sites this orbiter will inspect all over the 
planet."

The orbiter carries six instruments for studying every level of 
Mars from underground layers to the top of the atmosphere.  Among 
them, the most powerful telescopic camera ever sent to a foreign 
planet will reveal rocks the size of a small desk. An advanced 
mineral-mapper will be able to identify water-related deposits in 
areas as small as a baseball infield. Radar will probe for buried 
ice and water. A weather camera will monitor the entire planet 
daily. An infrared sounder will monitor atmospheric temperatures 
and the movement of water vapor.

The instruments will produce torrents of data. The orbiter can 
pour data to Earth at about 10 times the rate of any previous Mars 
mission, using a dish antenna 3 meters (10 feet) in diameter and a 
transmitter powered by 9.5 square meters (102 square feet) of 
solar cells. "This spacecraft will return more data than all 
previous Mars missions combined," said Jim Graf, project manager 
for Mars Reconnaissance Orbiter at NASA's Jet Propulsion 
Laboratory, Pasadena, Calif.

Scientists will analyze the information to gain a better 
understanding of changes in Mars' atmosphere and the processes that 
have formed and modified the planet's surface.  "We're especially 
interested in water, whether it's ice, liquid or vapor," said 
JPL's Dr. Richard Zurek, project scientist for the orbiter.  
"Learning more about where the water is today and where it was 
in the past will also guide future studies about whether Mars has 
ever supported life."

A second major job for Mars Reconnaissance Orbiter, in addition 
to its own investigation of Mars, is to relay information from 
missions working on the surface of the planet. During its planned 
five-year prime mission, it will support the Phoenix Mars Scout, 
which is being built to land on icy soils near the northern polar 
ice cap in 2008, and the Mars Science Laboratory, an advanced 
rover under development for launch in 2009. 

However, before Mars Reconnaissance Orbiter can begin its main 
assignments, it will spend half a year adjusting its orbit with an 
adventurous process called aerobraking. The initial capture by 
Mars' gravity on March 10 will put the spacecraft into a very 
elongated, 35-hour orbit. The planned orbit for science observations 
is a low-altitude, nearly circular, two-hour loop. To go directly 
into an orbit like that when arriving at Mars would have required 
carrying much more fuel for the main thrusters, requiring a larger 
and more expensive launch vehicle and leaving less payload weight 
for science instruments. Aerobraking will use hundreds of 
carefully calculated dips into the upper atmosphere -- deep enough 
to slow the spacecraft by atmospheric drag, but not deep enough to 
overheat the orbiter.

"Aerobraking is like a high-wire act in open air," Graf said. 
"Mars' atmosphere can swell rapidly, so we need to monitor it 
closely to keep the orbiter at an altitude that is effective but 
safe."  Current orbiters at Mars will provide a daily watch of the 
lower atmosphere, an important example of the cooperative activities 
between missions at Mars. 

Additional information about Mars Reconnaissance Orbiter is 
available online at:

http://www.nasa.gov/mro

The mission is managed by JPL, a division of the California 
Institute of Technology, Pasadena, for the NASA Science Mission 
Directorate, Washington. Lockheed Martin Space Systems, Denver, is 
the prime contractor for the project and built the spacecraft. 

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