KH-3 Corona

KH-3 7 [USAF]

KH-3 9 [USAF]

The KH-3 (Keyhole-3) was third version in the Corona-program to build an optical reconnaissance satellite. These satellites were all launched under the name Discoverer.

The KH-3 payload consisted of the further improved C''' (Corona triple-prime) single panoramic camera and a single General Electric return vehicle (SRV, Satellite Return Vehicle). The C'''-camera was built by Itek Corporation and with a f/3.5 aperture and 61 cm focal length had a ground resolution of 7.5 m.

The satellite was based on the Agena-B upper stage, which provided attitude control in orbit. The film return capsule carried its own small solid-fuel retro motor to deorbit at the end of the mission with mid-air recovery of the returning capsule by a specially equipped aircraft.

The last mission of thi series, KH-3 9, was modified and used the forward structure of the later KH-4 series with the KH-3 camera.

Nine KH-3 satellites were launched, of which five resulted in a successful return of film. Two missions failed to orbit. KH-3 8 deployed the samll Oscar 1 ammateur satellite.