On November 5, 2004, about 0830 mountain standard time, a Cessna 172S, N20519, made a hard landing on runway 35 at the Stellar Airpark, Chandler, Arizona. Angel Air, Inc., Chandler, operated the airplane. The student pilot was not injured during the solo instructional flight. The airplane sustained substantial damage. The flight was performed under the provisions of 14 CFR Part 91, and visual meteorological conditions prevailed. No flight plan was filed. The flight originated from Chandler about 0730. A fixed base operator located at the Stellar Airpark reported to the National Transportation Safety Board investigator that he heard the airplane bounce during the landing mishap. Thereafter, the witness redirected his attention toward the airplane. The witness reported that he observed three additional pilot-induced oscillations, heard the engine power increase, and observed the elevator move up and down. On the third bounce, the witness heard the airplane's propeller impact the runway. On the fourth and final bounce, the airplane skidded to a halt about midfield. The firewall was observed bent during the subsequent airplane inspection. The student pilot, who had about 2.2 hours of total solo flying experience, did not report any mechanical malfunction with the airplane during the accident flight.