On April 29, 1995, at 1605 eastern daylight time, a LET L-23 Super Blanik, N152AT, was substantially damaged during an aborted takeoff at the Spartanburg Downtown Memorial Airport, Spartanburg, South Carolina. The private pilot was not injured, and his passenger had minor injuries. The glider was operated under the provisions of 14 CFR Part 91 by the pilot. Visual meteorological conditions existed at the time, and no flight plan was filed for the local, personal flight. The flight was originating at the time of the accident. The pilot reported that the glider was not gaining sufficient airspeed during the takeoff roll. The tow plane pilot released the glider, and the takeoff was aborted. Due to obstructions at the departure end of the runway, the pilot attempted to maneuver the glider into an open area. The left wing contacted the ground first, and the glider ground looped. Structural damage to the wings and fuselage resulted. The pilot reported that when he was exiting the glider, he noticed that the speed brakes were in the deployed position, which correlated with the position of the speed brake handle.