Engineers troubleshooting an apparent alignment problem with one of two drive motors in a mechanism needed to rotate new solar arrays on the international space station apparently have resolved the glitch, officials said late today.

Details were not immediately available, but sources said the problem may have been triggered by a subtle computer commanding issue. Late today, a NASA spokeswoman confirmed the drive motor in question had been successfully engaged more than three hours after the problem first cropped up, delaying initial deployment of the new solar arrays.

Engineers now plan to press ahead with checkout of the solar alpha rotary joint, rotating it through 360 degrees using the now-engaged motor, but it's not yet clear when they might begin the initial deployment of the station's new solar arrays.

The 2,500-pound solar alpha rotary joint, or SARJ, is the centerpiece of the newly installed P3, or port three, truss that was attached to the left side of the station's main solar power beam Tuesday. It is designed to rotate outboard solar arrays so the panels can stay face on to the sun as the station circles the globe.

Engineers had hoped to begin the initial deployment of the new P4 solar arrays attached to the SARJ this evening, extending the panels a few feet to relieve compression after years of storage. The Atlantis astronauts are scheduled to fully deploy the 115-foot-long solar wings early Thursday.

But during SARJ checkout this afternoon, engineers ran into problems with one of two redundant drive motors.

One drive lock assembly, or DLA, successfully rotated the P4 arrays 180 degrees in an afternoon test. But when engineers attempted to carry out a 360-degree rotation with the redundant DLA, a sensor indicated an apparent misalignment in the gear train. A procedure was executed to clear the problem, but the misalignment indication remained.

Flight controllers then decided to hold up the initial array deployment while they assessed what, if anything, needed to be done.

Additional coverage for subscribers:
VIDEO: PORT 3/PORT 4 TRUSS KEEL PIN REMOVED AND STOWED PLAY
VIDEO: HELMETCAM OF BURBANK REMOVING SARJ RESTRAINT PLAY
VIDEO: SPACEWALKERS PAUSE FOR PICTURE TIME PLAY
VIDEO: STEVE MACLEAN REPORTS LOST BOLT PLAY
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VIDEO: PIPER UNFOLDS SOLAR BLANKET BOXES SHORT | FULL
VIDEO: SECOND WING'S STRUCTURE DEPLOYED BY PIPER PLAY
VIDEO: FIRST SOLAR WING'S STRUCTURE DEPLOYED BY TANNER PLAY
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VIDEO: TRUSS HANDED FROM SHUTTLE ARM TO STATION ARM PLAY
VIDEO: ARM MANEUVERS TRUSS OVER SHUTTLE WING PLAY
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VIDEO: ATLANTIS WELCOMED ABOARD THE STATION PLAY
VIDEO: DOCKING REPLAY FROM CAMERA ON SHUTTLE ARM PLAY
VIDEO: SHUTTLE ATLANTIS DOCKS TO THE STATION PLAY
VIDEO: ATLANTIS' BREATH-TAKING FLIP MANEUVER PLAY
VIDEO: CREW'S CAMCORDER FOOTAGE OF EXTERNAL TANK PLAY
VIDEO: NARRATED ANIMATION PREVIEWING TRUSS UNBERTHING PLAY
VIDEO: NARRATED ANIMATION PREVIEWING THE DOCKING PLAY
VIDEO: NARRATED ANIMATION OF PAYLOAD BAY CONFIGURATION PLAY
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VIDEO: BRIEFING ON TANK'S PERFORMANCE DIAL-UP | BROADBAND
VIDEO: TANK'S ONBOARD CAMERA LIFTOFF TO SEPARATION PLAY
VIDEO: FLIGHT DIRECTOR EXPLAINS INSPECTIONS PLAY
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VIDEO: HOUSTON RADIOS DEBRIS REPORT TO CREW PLAY
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LAUNCH REPLAYS:
VIDEO: BEACH MOUND TRACKER PLAY
VIDEO: CAMERA IN FRONT OF PAD PLAY
VIDEO: BANANA CREEK VIEWING SITE PLAY
VIDEO: VEHICLE ASSEMBLY BUILDING ROOF PLAY
VIDEO: PAD 39B SIDE PERIMETER PLAY
VIDEO: PLAYALINDA BEACH TRACKER PLAY
VIDEO: PLAYALINDA BEACH ZOOM PLAY
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VIDEO: UCS 11 TRACKER PLAY

VIDEO: MISSION SPECIALIST 4 STEVE MACLEAN BOARDS ATLANTIS PLAY
VIDEO: MISSION SPECIALIST 3 HEIDE PIPER BOARDS PLAY
VIDEO: MISSION SPECIALIST 2 DAN BURBANK BOARDS PLAY
VIDEO: MISSION SPECIALIST 1 JOE TANNER BOARDS PLAY
VIDEO: PILOT CHRIS FERGUSON BOARDS PLAY
VIDEO: COMMANDER BRENT JETT BOARDS PLAY

VIDEO: ASTRONAUTS EMERGE FROM CREW QUARTERS PLAY
VIDEO: CREW SUITS UP FOR LAUNCH TO SPACE PLAY
VIDEO: FINAL INSPECTION TEAM CHECKS ATLANTIS PLAY
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