NASA's Mars Reconnaissance Orbiter, a spacecraft designed to snap the clearest images yet of the Red Planet, will be launched from Earth by Lockheed Martin's Atlas 3 rocket in August 2005, the space agency said Tuesday.

The contract was booked through Lockheed Martin Commercial Launch Services, a division of International Launch Services. ILS is the joint U.S./Russian firm that markets Atlas and Proton rockets.

The 21-day planetary launch period for the Mars Reconnaissance Orbiter extends from August 8 to August 28, 2005. Launch will occur from Cape Canaveral, Florida.

"We're pleased to be selected for such an important mission," said ILS President Mark Albrecht. "This was a best-value, low-risk proposition, using the proven Atlas 3 vehicle. Its 100 percent successful performance was a key discriminator in NASA's selection of Atlas. Planetary missions like these are the bedrock of NASA's science mission and we are very proud that the Administration has placed its trust in Atlas."

The Atlas 3 launcher is evolved from the Atlas 2 series, and flew successfully in May 2000 and February 2002.

An artist's concept of Mars Reconnaissance Orbiter. Photo: NASA/JPL

MRO will be placed into a 200 by 155 mile polar orbit around Mars so its six main science instruments can gather high-resolution imagery of Mars, continue NASA's efforts to search for water and identify future landing sites on the planet's surface. Scientists say the craft will see objects as small as a beach ball.

"A new generation of reconnaissance instruments on MRO with unprecedented capabilities will pave the way for identifying the most compelling sites on Mars for sample return and ultimately for human exploration," said Dr. Edward Weiler, Associate Administrator for Space Science at NASA Headquarters in Washington.

The specific scientific objectives of the MRO mission include researching the processes of present and past climate change on Mars, searching the surface and shallow-subsurface for sites that show evidence of water-related activity, investigating the processes that are responsible for the formation of the ubiquitous layers that have been observed on Mars, and probing the shallow-subsurface to identify regions where three-dimensional layering could indicate the presence of ice or possibly lenses of liquid water.

Lockheed Martin Astronautics is building the 4,355-pound craft.