Mars craft taps brakes, snaps first photo

Odyssey's first visible image (right) zooms in on a section of the Mars southern polar region as seen with the probe's thermal camera (middle).

By Richard Stenger
CNN

(CNN) -- A new spacecraft near Mars has begun its main braking maneuvers, skimming through the atmosphere to slow down and settle into orbit.

One concern of mission managers is violent dust turbulence on the planet, which the NASA probe captured in its first visible photograph.

The 2001 Mars Odyssey, which arrived in late October, needs about 15 hours to complete one of its long, looping orbits. When it reaches its final orbital path in January, the probe will make the trip in two hours.

Periodic dips into the atmosphere shape the orbit of the satellite, which will begin scientific operations in February. Right now it passes within 68 miles (109 kilometers) of the surface during its closest approach.

"This … occurs over the north polar region on Mars, in a relatively low density region surrounded by strong winds like the jet stream on Earth," said project scientist Richard Zurek of NASA's Jet Propulsion Laboratory in a statement.

During such dives, the weather can be a major concern. Another NASA satellite, Mars Global Surveyor, which has orbited the red planet since 1997, is monitoring the planet for dust storms that could affect the upper atmosphere.

If needed, Odyssey could use its own instruments to watch for such threatening weather systems. In fact, during the first test of its camera in visible wavelengths, the probe photographed thick haze along the edge of the southern ice cap, evidence of massive dust storms that have raged over much of the planet for months.

The photograph, released this week by NASA, was taken in early November from an altitude of about 13,600 miles (22,000 kilometers) during late spring in the martian southern hemisphere. The space agency released the probe's first thermal image earlier this month.

The $300-million mission will take thermal and visible pictures, search for minerals and signs of water, and serve as a communications relay for future probes.