The KH-4A (Keyhole-4A) represented the fifth iteration within the Corona program aimed at constructing optical reconnaissance satellites. It was equipped with two J-1 panoramic cameras, each having a focal length of 61 cm and providing a ground resolution of 2.7 meters. Additionally, the KH-4A carried a 4 cm index camera with a focal length of 38 mm, offering a ground resolution of 162 meters and a frame coverage of 308 km × 308 km.

The Tripos Sousea satellites were part of a series of so called Program 11 or P-11 "Subsatellite Ferrets", low orbit ELINT/SIGINT satellites to pinpoint and characterize different Radar emitters in the Soviet Union and Warsaw pact states.