Mars channel on the horizon?

All Mars, all the time. That could be a viewing option by the end of the decade, following the launch in 2007 of a spacecraft whose sole mission will be to handle communications signals between Mars and Earth.

"If all goes as we'd like it to...you might be able to tune into the Mars channel," said Scott Hubbard, Mars program director at NASA headquarters in Washington, D.C.

But even before then, NASA expects to have in place a Mars orbiter able to upload data from the red planet's surface and send it to Earth. The telecom link is planned as part of the Mars Reconnaissance Orbiter mission in 2005.

The orbiter's primary mission over two years will be to survey the planet's surface. But it also will carry sufficient fuel and instruments to serve as a relay link for future missions. Spacecraft sent to the planet's surface will send its data first to the orbiter, which will then forward it to Earth, Hubbard said.

Having the system in place will eliminate the need for installing telecom systems in every spacecraft launched to Mars, thereby making more room for scientific payloads, he said.

However, he noted that the 2005 craft will circle the planet in a polar orbit, which is good for scientific study but not so good for telecommunications. The dedicated communications orbiter to be launched in 2007 will enter a more equatorial orbit, he said.

"We'll be in an era of being able to provide nearly continuous viewing of the surface of Mars," he said.

The orbiter for the 2005 launch is to be designed by NASA's Jet Propulsion Laboratory and the California Institute of Technology. They are putting together a request for proposals for industries interested in developing the spacecraft.

According to the space agency, the RFP will be released in February, with selections to be made this summer.