Space Station Chimera was a scientific research space station in the Third Zone. The scientists Kartz and Reimer conducted time travel experiments on it. Dastari was the station Head of Projects, and Shockeye of the Quawncing Grig was the chef. Sontarans attacked the station as part of Dastari's plan to kidnap the Second Doctor, who had been sent by the Time Lords to investigate the experiments. Almost everyone on the station was killed by the Sontarans.
On seeing the station on the TARDIS scanner screen, Jamie McCrimmon was amazed by its size, saying it was "like twenty castles in the sky." (DW: The Two Doctors)
Behind the scenes
In the novelisation of The Two Doctors the station is called "Space Station J7."