You're Right! In 1997 it was determined that the orbit was unstable due to greater than expected solar activity. On July 13, 1979, Skylab impacted the Earth's surface. One of the impact sites was the town of Esperance, Australia. Strangely enough, it landed atop a jackrabbit! They have pieces on display at the local museum, and reportedly fined NASA $400 for littering! The above photo is part of a titanium sphere (one of 22) used to house the nitrogen required for the operation of the thruster altitude control system of Skylab. Skylab was launched from the John F kennedy Space Center on May, 1973. It completed 34,981 orbits of earth before crashing to earth in the early hours of July 13,1979.