NASA on Friday enlisted the help of a space probe orbiting Mars to search for another spacecraft missing around the Red Planet.

The Mars Global Surveyor lost touch with Earth for two days earlier this month. Last week, engineers received a weak signal with no data. Since then, the spacecraft has not confirmed receiving a command to point one of its transmitters to Earth.

On Friday, the space agency directed another probe, the Mars Reconnaissance Orbiter, to use its cameras to scan the area where the Global Surveyor might be.Scientists will not know until early next week whether the Reconnaissance Orbiter located the missing probe, said Veronica McGregor, spokeswoman for NASA's Jet Propulsion Laboratory, which manages both spacecraft.

"We still don't know if it's in the field of view,'' McGregor said.

Launched on Nov. 7, 1996, to systematically map Mars, the Global Surveyor is the longest-operating Martian exploration craft. It has discovered features suggesting water once flowed on the planet's surface and looked at potential landing sites for future exploration.

The Reconnaissance Orbiter, which slipped into orbit last year, is the most powerful probe ever sent to the Red Planet.