It hasn't been a good year for Mars missions. But one Mars probe is turning in an award-winning performance this month as "Best Spacecraft in a Supporting Role."

Once envisioned primarily as a massive photography and mapping mission, NASA's Mars Global Surveyor, orbiting the planet since 1997, has stepped into a different job.

Not so surprising is the fact that the agency plans within days to use the orbiter's camera to search for Mars Polar Lander, lost at Mars on December 3.

But the role that the orbiter took on earlier this month was more unusual. As NASA struggled to contact the Mars Polar Lander and Deep Space 2 probes, the Global Surveyor acted as a communications relay between Earth and Mars.

The idea came from French scientist Jacques Blamont, who was in charge of a joint French-Russian experiment, a scientific balloon that was to be deployed in the martian atmosphere.

Blamont was at NASA one day when Mars Observer planners asked for suggestions on how to improve their own spacecraft. That mission later was lost at Mars in 1993, but in the planning stages, Blamont suggested adding a communications relay.

"Always from the beginning I felt that we had to have better communication in Mars exploration," Blamont says.

He knew his balloon badly needed a better means of sending its data to Earth. A Russian orbiter was assigned that job, but it wasn't going to be enough, he thought.

Blamont knew that Mars Observer, slated for a polar orbit, should pass over the balloon's position twice daily, offering plenty of chances for communications with Earth.

But how to add that relay to Mars Observer? That's where a scientist named Mike Malin came in. The one instrument aboard Mars Observer that could be altered to handle the job was its camera -- a camera that Malin was building.

"I opened my mouth and said, 'Yeah, we can take data from them,'" Malin remembers. "Then later, I thought better of it."

Adding relay duties would interfere with his plans to photograph Mars. "I fought it tooth and nail," Malin says. But he lost the battle.

In 1993 the Mars Observer spacecraft blew up before going into orbit around the Red Planet. Meanwhile, Blamont's balloon was postponed, then canceled. The plans for a Mars relay fell by the wayside.

Then, last year, NASA was looking for ways to improve communications with the planned Deep Space 2 microprobes. They looked to Malin's Mars Observer Camera (MOC) aboard the Mars Global Surveyor, already in martian orbit, which also is equipped with circuitry for communications relay.

The Surveyor would offer much higher rates of transmission than the spacecraft could achieve broadcasting directly to Earth. Malin agreed to the new role for his spacecraft. ("I actually like to help," he says.)

Flash forward to September, when the Mars Climate Orbiter was lost, robbing both the probes and the Mars Polar Lander of their primary communications link with Earth.

Suddenly Malin's camera was crucial. Its Mars Relay ability would help salvage the mission.

"I feel gratified that the Mars Relay and the MOC together can actually make a contribution," Malin says, adding that the Global Surveyor's new role has given the mission some unexpected notoriety.

"The fact that we are there and can do this does showcase the fact that Mars Global Surveyor is not the boring mission that a lot of people think it is."

Malin no longer regrets that Blamont volunteered his camera for its new role. Malin said recently, "I saw [Blamont] the other night, and I thanked him."

Unfortunately, even the Mars Relay could not raise a signal from the Deep Space 2 probes or the Polar Lander.

Early on the morning of December 7, when Polar Lander's moment of truth arrived, it was Malin's voice that came on the line from San Diego to deliver the bad news: once again, Mars Global Surveyor had not received any data from the lander.

In the Polar Lander mission control room, Flight Operations Manager Sam Thurman told Malin, "Thanks for hanging in there with us."