From TARDIS Index File, the free Doctor Who reference.

International Space Command ( sometimes refered to as International Space Control) was an Human organisation dedicated to exploring space. It was esablished as early as 1986 (DW: The Tenth Planet) and continued to exist late as 2070. (DW: The Moonbase) Its headquarters were located in Geneva.

The ISC maintained a South Pole base, capable of tracking manned atmospheric probes such as the Zeus IV. By 1986 they were flying Lunar missions, and controlled one of the two or three Z-bombs the Earth possessed. (DW: The Tenth Planet) By the 2050s they maintained a Moonbase from which they manipulated the Earth's Weather. (DW: The Moonbase)

The ISC may well have evolved later into the Interplanetary Space Command.