A pioneering demonstration of communications between the European Space
Agency’s Mars Express orbiter and NASA’s Mars exploration rover, Spirit,
has succeeded.

On 6 February, while Mars Express was flying over the area that Spirit is
examining, the orbiter transferred commands from Earth to the rover and
relayed data from the rover back to Earth.

"This was the first in-orbit communication between ESA and NASA
spacecraft, and we have also created the first working international
communications network around another planet," said Rudolf Schmidt, ESA’s
Project Manager for Mars Express. "Both are significant achievements, two
more ‘firsts’ for Mars Express and the Mars exploration rovers."

Jennifer Trosper, Spirit Mission Manager at NASA’s Jet Propulsion
Laboratory, California, USA, said, "We have an international
interplanetary communications network established at Mars."

ESA and NASA planned this demonstration as part of continuing efforts to
cooperate in space.

The commands for the rover were first transferred from Spirit’s operations
team at JPL to ESA’s European Space Operations Centre in Darmstadt,
Germany, where they were translated into commands for Mars Express. The
translated commands were transmitted to Mars Express, which used them to
command Spirit. Spirit used its ultra-high-frequency antenna to transmit
telemetry information to Mars Express, and the orbiter then relayed the
data back to JPL via the European Space Operations Centre.

"This is excellent news," said JPL’s Richard Horttor, project manager for
NASA’s roles in Mars Express. "The communication sessions between Mars
Express and Spirit were pristine. Not a single bit of data was missing or
added, and there were no duplications."

This exercise demonstrates the increased flexibility and capabilities of
inter-agency cooperation and highlights the close mutual support that is
essential when undertaking international space exploration.

More information on the ESA Mars Express mission can be found at
http://mars.esa.int