KH-3 Corona

KH-3 5 [USAF]

KH-3 6 [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 this series, KH-3 6, was modified and used a forward structure similar to the later KH-4 series with the KH-3 camera.

Six KH-3 satellites were launched, of which four resulted in a successful return of film. One mission failed to orbit. KH-3 5 deployed the small OSCAR 1 ammateur satellite.

Secondary Payloads

Some satellites carried secondary payloads mounted on the satellite:

• Discoverer 29 (KH-3 1) carried the Texas Pint (Aftrack 12) ELINT payload, the Vela Hotel Package 1 and a GRD Package (Module 103?)
• Discoverer 30 (KH-3 2) carried the Topsoc 1 (Aftrack 13) ELINT payload and a GRD Package (Horizon Sensor Experiment)
• Discoverer 31 (KH-3 3) carried the Topsoc 2 (Aftrack 14) ELINT payload, the Vela Hotel Package 2 and a GRD Package (Module 105?)
• Discoverer 32 (KH-3 4) carried the Topsoc 3 (Aftrack 15) ELINT payload, Research Payload Kit No. 3B (Module 106?) and a TR-17 type SECOR transponder
• Discoverer 36 (KH-3 5) carried the Grape Juice 1 (Aftrack 17) COMINT payload, the Vela Hotel Package 4, the GRD Package (Module 108?) and a TR-17 type SECOR transponder
• Discoverer 37 (KH-3 6) carried the Taki (3) (Aftrack 19) ELINT payload and the LPARL Aurora 1962a (Module 109?) payload