Radar site 200 mile range at Ellington AFB.
Radar operator observed an unidentified object coming in from northwest at a high rate of speed-
About 8 of us went outside to view object was starting & stopping, when startling white sparks came out beneath craft.
They turned to orange, then white as it accelerated again.
Saucer shape with revolving lights on top, inside glass like structure.
Craft made a U turn and went back northwest.
Officer in charge reported it to NORAD, with no reply received, as far as I know.