CAPE
CANAVERAL, Fla. -- The pieces are coming together for NASA's next Mars probe, a
recon satellite designed to scout out red planet landing sites for future
explorers.
The Mars Reconnaissance
Orbiter (MRO) is awaiting launch atop its Atlas 5 rocket, which is set to loft
the spacecraft toward the red planet on Aug. 10 in a 7:53 a.m. EDT (1153
GMT).
"It's a
real mixture of feelings," MRO project manager James Graf told SPACE.com in the clean room. "We're
elated that we're ready to go launch, but white-knuckled hoping that everything
will go as we expect."
NASA
researchers tout the MRO spacecraft as the largest orbiter aimed at Mars in the
last 30 years. Standing about 22 feet (six meters) tall and spanning 44 feet
(13 meters) wide, it certainly outsizes the agency's
other red planet orbiters, Mars Global Surveyor and Mars Odyssey. The orbiter
weighs about 4,806
pounds (2,180 kilograms), but came in about 112 pounds (51 kilograms)
underweight allowing engineers to fill that weight with additional propellant,
extending its flight lifetime out to about 2014.
"This is a
big mission for us," said Doug McCuistion, director
of NASA's Mars Exploration Program at the agency's science mission directorate,
in a preflight press briefing. "It's the most powerful suite of instruments
ever sent to another planet."
The MRO
spacecraft is set to be integrated with its Atlas 5 booster, equipped with a
Centaur upper stage, at Launch Complex 41 of Cape Canaveral Air Force Station on
July 28, launch officials said.
A new pathfinder
MRO will
carry a hefty science payload to Mars, with six instruments designed to track
Martian weather, resolve objects the size of a kitchen table and measure the
planet's composition and atmospheric structure with more detail than ever
before.
"The MRO
spacecraft is many things," said Richard Zurek, the
mission's project scientist at NASA's Jet Propulsion Laboratory (JPL). "It's a
weather satellite, it's a geological surveyor, and it's a scout for future
missions."
The orbital
spacecraft is expected to be the vanguard for two landers
NASA plans to launch toward Mars in the next five years, and will identify
potential landing targets. The Phoenix lander is
currently scheduled to launch in 2007 and touchdown in the planet's polar
region. A large rover, the Mars Science Laboratory, is expected to launch in
2009.
Eyes on Mars
To prepare
for those missions, MRO carries three cameras, one spectrometer, a climate sounder and subsurface radar, all designed to shed
new light on the structure and composition of Mars.
MRO's
High-Resolution Imaging Science Experiment (HiRISE)
will photograph Mars' surface with such detail, researchers expect to resolve
objects as small as four feet (1.3 meters) wide. To get a wider view, the
orbiter's Context Camera will gather images about 25 miles (40 kilometers)
across, with a resolution of about eight kilometers per pixels.
A third
camera, the Mars Color Imager, is expected to generate a global map of Martian
weather and track large-scale dust storms, day-to-day weather conditions, as
well as atmospheric and polar cap changes.
"Each day
we will build up a full weather map of Mars," Zulek
said of the Mars Color Imager. "And [the camera] is the size of a hand."
MRO's Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM, will
observe the red planet in the visible and infrared range to pick out minerals
and other materials that may have formed in water or wet conditions some time
in the planet's past.
The Mars
Climate Sounder, an instrument designed to study the changes in Mars' atmospheric
composition and temperature according to its height. The tool is expected to
take measurements every three miles (five kilometers) between space and the
Martian surface.
Finally, a
shallow subsurface SHARAD radar - similar but smaller to one that rides aboard
Europe's Mars Express probe - will probe for underground water down to the
first few hundred feet or so (up to one kilometer) beneath the Martian soil.
The MARSIS radar tool aboard Mars Express, on the other hand, will look deeper,
probing as deep as three miles (five kilometers) beneath Mars' surface.
"The [SHARAD]
radar profile will build up a 3D view of Mars," Zulek
said.
Launch: the first step
Before the
MRO spacecraft can cull secrets from the red planet, it must first leave its
home world.
After
launch, it should take MRO about six months to reach Mars, then
another seven months or so to slow adjust its eccentric orbit into a 250-mile (400-kilometer)
high circle. The orbiter will use aerobraking to adjust
its orbit, swooping in close to Mars and using its atmosphere to slow the
spacecraft.
Engineers are
taking care not to damage any of MRO's components
during the integration with its launch vehicle, including the spacecraft's
massive solar arrays.
"These are
the biggest solar arrays every sent to another planet," Graf said.
Craig
Calvin, an MRO systems engineer for Lockheed Martin, said the orbiter's solar
panels span a total of about 20 square meters and carry about 7,000 solar
cells. All those cells are need to generate the five kilowatts of power in
Earth orbit, though that power output will diminish to about two kilowatts of
power at Mars, Calvin said, adding that MRO's
instruments and equipment only requires one kilowatt to function.
"It's
fantastic that after five years, we're ready to go," Graf said. "I'm looking
forward to the first image that comes back from that first pass."
advertisement
