Skylab

Skylab was the first American space station, launched in 1973. The Doctor claimed to have been involved in its construction. (DW: Tooth and Claw)

In 1979, the now-abandoned Skylab was used by the Zalphons as their base, but an accident on board caused it to crash back to Earth, the debris falling in western Australia. The Doctor, with the assistance of young Harvey, defeated the Zalphons. (DWA: Bennelong Point)

In an unrelated incident, the Doctor saved a man in the Australian desert from being killed by a piece of Skylab by advising him to take three steps to the left. (DWM: Three Steps to the Left)