[meteorite-list] Fast-Talking NASA Spacecraft Starts Final Approach to Mars

[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
Merrilee Fellows (818)393-0754			                 				
NASA Headquarters, Washington

News Release: 2006-032 		       March 8, 2006               
                                   
Fast-Talking NASA Spacecraft Starts Final Approach to Mars

NASA's Mars Reconnaissance Orbiter has begun its final approach 
to the red planet after activating a sequence of commands 
designed to get the spacecraft successfully into orbit.

The sequence began Tuesday and will culminate with firing the 
craft's main thrusters for about 27 minutes on Friday -- a foot 
on the brakes to reduce velocity by about 20 percent as the 
spacecraft swings around Mars at about 5,000 meters per second 
(about 11,000 miles per hour). Mission controllers at NASA's Jet 
Propulsion Laboratory, Pasadena, Calif., and Lockheed Martin 
Space Systems, Denver, are monitoring the events closely.

"We have been preparing for years for the critical events the 
spacecraft must execute on Friday," said JPL's Jim Graf, project 
manager.  "By all indications, we're in great shape to succeed, 
but Mars has taught us never to get overconfident. Two of the 
last four orbiters NASA sent to Mars did not survive final 
approach."

Mars Reconnaissance Orbiter will build upon discoveries by five 
successful robots currently active at Mars: NASA rovers Spirit 
and Opportunity, NASA orbiters Mars Global Surveyor and Mars 
Odyssey, and the European Space Agency's Mars Express orbiter. 
It will examine Mars' surface, atmosphere and underground layers 
in great detail from a low orbit. It will aid future missions by 
scouting possible landing sites and relaying communications. 
It will send home up to 10 times as much data per minute as any 
previous Mars mission. 

First, it must get into orbit. The necessary thruster burn will 
begin shortly after 1:24 p.m. Pacific Time on Friday.  Engineers 
designed the burn to slow the spacecraft just enough for Mars' 
gravity to capture it into a very elongated elliptical orbit. A 
half-year period of more than 500 carefully calculated dips into 
Mars' atmosphere -- a process called aerobraking -- will use 
friction with the atmosphere to gradually shrink the orbit to 
the size and nearly-circular shape chosen for most advantageous 
use of the six onboard science instruments. 

"Our primary science phase won't begin until November, but we'll 
actually be studying the changeable structure of Mars' 
atmosphere by sensing the density of the atmosphere at 
different altitudes each time we fly through it during 
aerobraking," said JPL's Dr. Richard Zurek, project scientist 
for the mission.

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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