Possible third piece of silent probe spotted

Some of the suspected Contour parts, seen by a telescope on Kitt Peak in Arizona.

(CNN) -- Astronomers detected an additional piece of what could be a $159 million spacecraft that became lost in space after trying to blast out of Earth orbit.

A ground-based telescope spied a pair of possible segments of the NASA probe on August 16, the day after flight managers ordered it to perform a critical engine burn.

Since beaming up the commands, engineers with the Comet Nucleus Tour (Contour) mission have been unable to contact the craft. But this week, University of Arizona researchers said they identified a possible third fragment of the ship.

Scientists speculate that a glitch during the thruster firing dislodged chunks of Contour or its rocket boosters, all going at nearly the same direction and speed.

Two are several hundred miles from each other. The other is thousands of miles away from the other.

"The objects are now more than 2 million kilometers from Earth, traveling at a steady 6.1 kilometers per second (3.8 miles per second)," the Contour team said in a statement.

Contour scientists will scale back attempts to communicate with the ship next week, but have not given up hope of contacting the probe, which was slated to fly near two comets in the coming years.

They will try to make contact once a week for three months, and then ramp up efforts when the spacecraft flies into a more favorable spot for communication.

"We know there's not much room for optimism through this week. Even the second week of December, when we have our best shot, changes are small, but it's still worth monitoring," said Robert Farquhar, the lead Contour scientist.

The Contour mission was designed and managed for NASA by the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.