On March 2, exactly 30 years after launch, NASA sent asignal to the Pioneer 10 spacecraft, which has not been heard from in more than7 months. The robot is 7.4 billion miles away, nearly at the edge of the solarsystem.

Within a day, the spacecraft phoned home.

"We are overjoyed that we still have the spacecraft,"said Robert Hogan, chief of NASA Ames Research Center's Space ProjectsDivision, where the Pioneer project is managed.

Engineers hailed the feat as a mark of good design.

"As an eternal optimist, I was confident it wouldsucceed," said Pioneer 10 Project Manager Larry Lasher. "Pioneer 10has been discounted in the past, but somehow it always manages to land on itfeet."

Scientists at NASA's Deep Space Network sent the signal froma dish in Goldstone, Calif., and received a return signal at a facility inMadrid, Spain. In April 2001, engineers made contact with Pioneer after eightmonths of silence. They last communicated in July 2001.

In 1983, Pioneer 10 became the first spacecraft to go beyondthe orbit of Pluto. It was also the first craft to fly through the asteroidbelt and make close-up photos of Jupiter.

The probe is now so far away it took roughly 22 hours forthe radio signal to make the round trip.

Eventually, Pioneer could provide clues about what goes onat the boundary of the solar system, a region called the heliosphere. Afterthat, it would be a long time before the craft would encounter much else.Scientists said it will pass the nearest star in about two million years.

Pioneer 10 carries a gold plaque engraved a map indicatingEarth's location in the solar system, along with a message of goodwill.