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Engineering and science information from NASA's Deep Space 1 was transmitted from the spacecraft to ground controllers today, and the mission team continues to analyze the data.

The spacecraft's infrared camera has returned four sets of valuable data which will help scientists determine the asteroid's composition. Called spectra, a form of data which break light into component colors much like a prism does (usually displayed as graphs), they cover different parts of the asteroid and were taken both before and after closest approach.

In addition to two black-and-white images taken about 70 minutes prior to closest approach, two black-and-white images of limited quality, taken 20 seconds apart at approximately 15 minutes after the encounter, have been returned.

Diagnosis of an apparent target tracking problem continues. If the asteroid were much dimmer than expected or if the camera was much less sensitive than expected, this would explain why the autonomous navigation system did not lock on to allow the camera to point at the asteroid during closest encounter. This possibility is being analyzed.

The spacecraft's xenon ion engine was fired at 9 a.m. Pacific time and will continue thrusting almost continuously for the next three months in preparation for flybys of two comets during a possible extended mission after the September 18, 1999, conclusion of Deep Space 1's primary mission.

Deep Space 1 is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC.