David McAlary, Voice of America, June 5, 2003

The skies around Mars are expected to get busier soon, and traffic on the ground will increase, too. The United States, Europe and Japan are sending spacecraft and landers to give them a broader and closer view of the Red Planet. The European and Japanese craft are already on their way, and the first of two American probes is to go up Sunday. A major goal is to find water and life.

NASA has been trying to get back to Martian soil since its successful 1997 landing mission. That one parachuted the Pathfinder lander down in a protective airbag, delivering a small rover that analyzed rocks and took stunning images of the terrain.

Doubling the mission enables NASA to bring the landers down on opposite sides of the Red Planet. They will extend panoramic cameras to let scientists select promising geological targets in areas where water is thought to have flowed.

But NASA researcher Jim Garvin says these are more capable rovers that can roam much farther than the one six years ago - up to one kilometer during the 90-day missions. For the first time, they will be able to steer themselves around obstacles without specific commands, and see rocks in much finer detail.

NASA's strategy is to seek further evidence of Martian water in its effort to determine if microbial life ever existed there or still does. In the 1997 mission, the shapes, composition, and placement of rocks revealed clear signs of ancient water flows. Mr. Garvin noted that American satellites circling Mars have reinforced this data, detecting landforms and soil movement that could be evidence of underground water.

A European Mars probe launched Monday on a Russian rocket has similar goals, but is technically more modest. A very small lander will separate from an orbiter and parachute to a cushioned landing. However, rather than roam, it will seek signs of life from a single location while the companion orbiter scans the planet with radar for underground water.

Japan's Nozomi mission, also set to arrive at Mars in December, has a different objective. As an orbiter only, it will study the red planet's thin atmosphere to determine why it has leaked into space and the impact solar radiation has had on the process.

Two-thirds of the more than 30 American and Russian missions to Mars since 1960 have failed. If all four U.S., European, and Japanese spacecraft arrive successfully this year, they will have beaten the odds.