On October 2, 1995, at 1730 central daylight time, a Socata TB-9, N152ND, nose gear collapsed after the student pilot lost control of the airplane during the go phase of a touch and go landing at Pryor Field in Decatur, Alabama. The supervised solo flight operated under the provisions of 14 CFR Part 91 with no flight plan filed. Visual weather conditions prevailed at the time of the accident. The airplane was substantially damaged, and the student pilot was not injured. The flight departed Huntsville, Alabama, at 1700 hours. According to the student pilot, this was his second supervised solo flight. He had completed one touchdown, and was on the go phase of the first of a series of touch and go landings. As the airplane accelerated for the takeoff, the airplane veered off the left side of runway 18. When the student pilot attempted to regain control of the airplane, the throttle knob came off the throttle control lever. The student pilot did not report a mechanical problem with the airplane. Examination of the airplane also failed to disclose a mechanical problem. This aircraft is equipped with an arm type throttle control lever; the throttle lever was still fully operational without the knob assembly.