On September 30, 2004, at 0710 eastern daylight time, N45667, a Cessna 150M, registered to and operated by a student pilot, veered off the runway and collided with tall brush while attempting a take-off roll on runway 7 at Seymour Airpark, Sevierville, Tennessee. The solo instructional flight was conducted under Title 14 CFR Part 91 and visual flight rules. Visual metrological conditions prevailed at the time of the accident and no flight plan was filed. The student pilot was not injured and the airplane sustained substantial damage. The flight originated from Seymour Airpark, Sevierville, Tennessee, on September 30, 2004, at 0709. According to the student pilot, the purpose of the flight was to complete a solo flight to Sky Ranch Airport, Knoxville, Tennessee, where the pilot and airplane were based. He stated that he contacted Sky Ranch airport to obtain the weather conditions, and the visibility there was 3 miles. He stated that he preflighted the airplane "according to standard procedures cleaned the windshield and side glasses of moisture." He stated that he performed a run-up, aligned the airplane on the centerline of runway 7, and initiated take-off roll. He stated at "fifty knots, the windshield and side glass fogged up to the point of zero visibility." He stated that "he sensed that the aircraft was drifting to the left," at which point he "unsuccessfully attempted to correct the path to the right." He stated that he retarded the throttle and began to "shut down the plane." The airplane's left wing collided with tall brush and bushes, nosed over in soft mud, and came to rest inverted. Post-accident examination of the accident scene revealed tire marks beginning at the approach end of runway 7, veering left off the runway for approximately 975 feet into brush and soft mud. Other marks were observed in the soft mud leading up to the inverted airplane. One blade of the propeller was buried in the mud. Examination of the airplane wreckage revealed the left outboard half of the wing was crushed aft and the right wingtip was separated. The vertical stabilizer was displaced to the right. The nearest weather reporting facility, McGhee-Tyson Airport, Knoxville, Tennessee, 10 nautical miles southwest of Seymour Airpark, Sevierville, Tennessee, at 0653, reported winds as 050 degrees at four knots, visibility of four statute miles in mist, and temperature-dew point of 12 degrees Celsius. Examination of the pilot logbooks revealed that an endorsement for repeated solo flights less than 25 nautical miles was not entered by a certified flight instructor. The Owner's Manual for the Cessna 150 states that the airplane is equipped with a cabin heat and ventilation system. Windshield defrost air is also suppiled by this system. The student pilot did not report using the defrost system.