Advanced Short Range Air-to-Air Missiles

 were a type of heat-seeking missile used by UNIT.

The missiles were equipped with infrared seekers that would lock on to flying craft, and release a blaze of flame that trailed behind it. The resulting explosion was big enough to send shockwaves across a large lake.

The missiles were used to shoot the mothership of a Rintlekk escape pod over Wasdale Head, causing the bracken on the hillside to burst into flame. (PROSE: At Childhood's End)