|Mission type||Optical reconnaissance|
|Operator||US Air Force/NRO|
|Harvard designation||1961 Psi 1|
|Mission duration||2 days|
|Spacecraft type||KH-3 Corona'''|
|Launch mass||1,150 kilograms (2,540 lb)|
|Start of mission|
|Launch date||30 August 1961, 20:00UTC|
|Rocket||Thor DM-21 Agena-B 323|
|Launch site||Vandenberg LC-75-3-4|
|End of mission|
|Decay date||9 September 1961|
|Perigee altitude||138 kilometers (86 mi)|
|Apogee altitude||511 kilometers (318 mi)|
Discoverer 29, also known as Corona 9023, was an American optical reconnaissance satellite which was launched in 1961. It was the first KH-3 Corona''' satellite, which was based on an Agena-B rocket.
The launch of Discoverer 29 occurred at 20:00 UTC on 30 August 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-3-4 at the Vandenberg Air Force Base. Upon successfully reaching orbit, it was assigned the Harvard designation 1961 Psi 1.
Discoverer 29 was operated in a low Earth orbit, with a perigee of 138 kilometres (86 mi), an apogee of 511 kilometres (318 mi), 82 degrees of inclination, and a period of 91 minutes. The satellite had a mass of 1,150 kilograms (2,540 lb), and was equipped with a panoramic camera with a focal length of 61 centimetres (24 in), which had a maximum resolution of 7.6 metres (25 ft). Images were recorded onto 70-millimeter (2.8 in) film, and returned in a Satellite Recovery Vehicle two days after launch, but all of the images returned were found to be out of focus. The Satellite Recovery Vehicle used by Discoverer 29 was SRV-554. Once its images had been returned, Discoverer 29 remained in orbit until it decayed on 9 September 1961.