Dynacron star drive
From Tardis Wiki, the free Doctor Who reference
The dynacron star drive was a device that Sarah Jane Smith had inside her attic at 13 Bannerman Road. (TV: Invasion of the Bane) Sarah Jane's dynacron star drive was not longer working, so Sarah Jane repaired it. After repairing it the dynacron star drive shined red, before that dynacron star drive was white. (TV: Revenge of the Slitheen)
Behind the scenes
According to the official SJA website the dynacron star drive was found in Leeds in England in 1996. It powered a spaceship engine on long haul flights between galaxies. The technology was dangerous in the wrong hands.