\<COLOUR 1> COMMENTS: \<COLOUR 0> One of a series of RORSATs (radar ocean reconnaissance satellites), the first of which (Cosmos 198) went into orbit on December 27, 1967; they are notable for their on-board nuclear reactor, which powers their powerful radar; Cosmos 954 gets out of control and plummets to Earth, breaking up and scattering radioactivity over northern Canada on January 24, 1978.