On July 16, 1998, at 0800 mountain daylight time, a Cessna 172N, N172AT, sustained substantial damage during a hard landing at Jefferson County Airport, Broomfield, Colorado. The student pilot and sole occupant was not injured and no flight plan was filed for this local area student solo instructional flight operating under Title 14 CFR Part 91. Visual meteorological conditions prevailed and no flight plan was filed. According to the student pilot, she was practicing touch-and-go landings and had to extend her pattern due to traffic and as a result, she had to add power to make the runway. The pilot's statement provided information that she landed fast, long, and hard and decided to go around. She had some communications difficulties with the tower during the go around when her head set plug came loose, but she indicated in her statement that her final landing was "the best landing I ever made." The pilot parked the aircraft on the ramp and several hours later, the damage was found by the Jefferson County Airport, FAA Air Traffic Manager.