Artist's concept of Nozomi (lower left) and Mars Express (upper right) working together in orbit around Mars. Photo: ESA.

Japanese and European Mars orbiters will keep each other company once they arrive at the red planet in 2003 and 2004. A recent meeting between the Mars Express and Nozomi teams forged an agreement to work together once their respective probes arrive in Martian orbit.

The two spacecraft will enter orbits around Mars that are perpendicular to one another, making them perfect for jointly monitoring atmospheric and weather conditions from separate orbits throughout their missions. Mars Express officials also say that other not yet defined operations will also be conducted using both craft.

Other plans outlined at the workshop included the opportunity for Japanese scientists to help European official with the complex testing procedures that Mars Express will undergo prior to its June 2003 launch. Japan will also take part in data analysis once Mars Express arrives at Mars.

European teams will process some of the data downlinked from Nozomi to keep its part of the deal. Because Nozomi has already been launched, Europe cannot aid in any hardware-related activities.

Also discussed during the meeting were plans to integrate both experienced scientists and younger team members from one mission into the other, ensuring both smooth joint operations and an even training flow for future researchers.

"There was a very fruitful atmosphere of cooperation and understanding between the scientists on the two teams, with members of both missions wanting to join the others' teams," said Mars Express project scientist Agustin Chicarro.

ESA and Japanese officials say they hope the cooperation lasts. "We're looking to the long term. We want to base our relationship on friendship based and mutual trust. For too long Europe and Japan have been looking for partners across different oceans. Now we realize that we're sitting at different ends of the same landmass," Chicarro later said.

Plans call for the two teams to gather once a year throughout the lifetimes of the missions to review the status of the agreement and of the missions themselves. ESA team members say that another meeting may be required later this year.

Nozomi is already en route to the red planet after its launch in 1998, while Mars Express is still under construction back on Earth with its launch targeted for June 1, 2003 aboard a Soyuz-Fregat rocket.