NASA
is ready to add one more spacecraft to the constellation of orbiters and
landers exploring the red planet.
The
Mars Reconnaissance Orbiter (MRO) is ready to put the brakes on, slowing itself
down for insertion into orbit around the planet. Arrival time is March 10 as
MRO fires its main thrusters to slow itself enough to be captured by Mars'
gravity.
Launched
last August, the instrument-loaded spacecraft has journeyed across the vacuum
void and will soon begin its unprecedented surveying of Mars.
MRO
has been performing extremely well during its cruise to the red planet, said
Doug McCuistion, NASA Mars Exploration Program Director at NASA Headquarters in
Washington, D.C.
Given
earlier Mars missions that have failed to reach the planet, McCuistion
cautioned: "Mars is hard. Mars can be unpredictable." Getting into Mars orbit
is not an easy task, he said during an MRO press briefing held today at NASA
Headquarters.
"We're
95 percent there," said James Graf, MRO Project Manager at the Jet Propulsion
Laboratory (JPL) in Pasadena, California. JPL is managing the $720 million
mission for the NASA Science Mission Directorate.
Crucial maneuver
To
slip into Mars orbit, MRO will fire its thrusters for about 27 minutes--decreasing
the velocity of the spacecraft by 18 percent. That maneuver is crucial;
otherwise the probe will sail right past Mars.
The
process of slowing down MRO at Mars is going to be a nail biter for ground
controllers.
"We're
doing a lot of first events," Graf explained. First, the propellant system to
fire MRO's thrusters must be pressurized. In addition, there are software
patches onboard the spacecraft that have not been used before, he said.
Once
MRO is firing its thrusters, it will go behind Mars--out of contact with mission
controllers. "We'll be out of touch for the next 30 minutes...so we will not see
the end of the burn itself," Graff said.
Start
of the suspenseful Mars Orbit Insertion (MOI) thruster firing is 1:25 p.m.
Pacific Standard Time, with MRO coming out from behind the planet at 2:16 p.m.
PST.
Deep dipping
Given
a successful MOI, the spacecraft will spend half a year dipping in and out of
Mars' atmosphere in a process tagged as "aerobraking"--adjusting its initial
35-hour elongated orbit into a nearly circular, two-hour loop around Mars.
MRO's
aerobraking is to take place from March into October and calls for hundreds of
precision-controlled dips into the upper atmosphere of Mars. Those dips have to
be deep enough to slow the spacecraft by atmospheric drag, but not so deep that
the orbiter becomes overheated.
The
primary science-gathering phase of MRO is slated to start in November 2006 and
last for over two years.
"MRO
opens a new chapter in the history of Mars exploration," said Bob Berry,
Director of Space Exploration Systems at Lockheed Martin Space Systems Company
near Denver, Colorado. The aerospace firm designed, built and operates MRO. The
spacecraft carries six instruments and features a set of solar arrays that
stretch tip-to-tip some 46 feet (14 meters), he said.
Berry said that MRO
carries enough propellant and energy supply to last more than 10 years.
Over and under observations
MRO
totes powerful instruments that can investigate every level of Mars: From
underground layers to the top of the planet's atmosphere.
For
one, the Mars-bound spacecraft is hauling the most powerful telescopic camera
ever sent outward to scan another planet. That gear can spot rocks the size of
a small desk.
MRO
will chart water-related deposits in areas as small as a baseball infield. The
Italian space agency supplied the mission with a radar designed to probe for
buried ice and water.
Also,
a weather camera will monitor the entire planet daily, while an infrared sounder
is assigned the duty to gauge atmospheric temperatures and the movement of
water vapor.
JPL's
Graf said that MRO will return more data than all previous Mars missions
combined.
Swimming in the data stream
Thanks
to the huge amount of data streaming from MRO, scientists can expect a real
intellectual leap forward in better understanding the red planet, said Michael
Meyer, NASA Mars Lead Scientist at NASA Headquarters.
Along
with revealing Mars as never before, Meyer said MRO will guide future mission
decisions too.
MRO's
powerful sensors can scope out the landing spot near the northern polar ice cap
where NASA's Phoenix lander is slated to touch down in 2008, as well as the
exploration zone in which the space agency's next rover--the Mars Science
Laboratory--will head for after its launch in 2009.
Even
those "little rovers that just won't quit"--NASA's Spirit and Opportunity robots--can
be seen by MRO, said NASA's McCuistion. MRO can also provide, he added, useful
data for some of the early decision-making as to where future human explorers
can safely land on Mars.
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