The Indian Space Agency was an Earth-based organisation headquartered in India dedicated to the exploration of space and the defense of Earth from threats originating in space. The ISA was in operation during the 24th century.
The Doctor was contacted by the agency in 2367 when an unidentified spaceship (later determined to be the Silurian Ark) was hurtling towards Earth. The ISA fired missiles at the Ark once it got close to Earth; however, due to the Doctor's efforts, the missiles locked on to the spaceship of Solomon the space pirate who massacred the Silurians who were aboard the Ark. (DW: Dinosaurs on a Spaceship)