NASA's Stardust spacecraft successfully completed a close flyby of asteroid Annefrank early today as an opportunity for a full dress rehearsal of procedures the spacecraft will use during its Jan. 2, 2004, encounter with it primary science target, comet Wild 2.

Annefrank is about 4 kilometers (2.5 miles) across. Stardust passed within about 3,300 kilometers (2,050 miles) of the asteroid at 0450 GMT today (11:50 p.m. EST Friday).

Radio signals confirming the basic health of the spacecraft after the flyby were received about 30 minutes later via an antenna at the Canberra, Australia, complex of NASA's Deep Space Network, said Thomas Duxbury, project manager for Stardust at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Stardust visually tracked the asteroid for 30 minutes as it flew by at a relative speed of about 7 kilometers (4 miles) per second, a major goal of this test opportunity. Although no dust was anticipated near the asteroid, the spacecraft's dust instruments were in use as they will be at Wild 2: the dust collector was open and the dust counter from the University of Chicago and dust mass spectrometer from Germany were turned on.

Images and information from the flyby period are being transmitted from the spacecraft today and through the coming week. Stardust's scientists and engineers are analyzing the data to maximize the probability of success during the 2004 encounter with comet Wild 2.

Stardust will bring samples of comet dust back to Earth in 2006 to help answer fundamental questions about the origins of the solar system. The mission's principal investigator is Prof. Donald Brownlee, an astronomer at the University of Washington, Seattle. Lockheed Martin Astronautics, Denver, Colo., built and operates the Stardust spacecraft.

Stardust is a part of NASA's Discovery Program of low-cost, highly focused science missions. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C.