Discoverer 28


Discoverer 28
Mission typeOptical reconnaissance
OperatorUS Air Force/NRO
Mission durationFailed to orbit
Spacecraft properties
Spacecraft typeCorona KH-2
Launch mass1,150 kilograms (2,540 lb)
Start of mission
Launch date4 August 1961, 00:01 (1961-08-04UTC00:01Z) UTC
RocketThor DM-21 Agena-B 309
Launch siteVandenberg LC-75-1-1
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
The launch of Discoverer 28

Discoverer 28, also known as Corona 9021, was an American optical reconnaissance satellite which was lost in a launch failure in 1961. It was the seventh of ten Corona KH-2 satellites, based on the Agena-B.[1]

The launch of Discoverer 28 occurred at 00:01 UTC on 4 August 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-1-1 at the Vandenberg Air Force Base.[2] It failed to achieve orbit after the Agena's guidance and control system malfunctioned.[3][4]

Discoverer 28 was to have operated in a low Earth orbit. The satellite had a mass of 1,150 kilograms (2,540 lb),[5] 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).[4] Images were to have been recorded onto 70-millimeter (2.8 in) film, and returned in a Satellite Recovery Vehicle. The Satellite Recovery Vehicle carried by Discoverer 28 was SRV-512.[5]


  1. ^ Krebs, Gunter. "KH-2 Corona". Gunter's Space Page. Retrieved 23 October 2020.
  2. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 26 June 2010.
  3. ^ Pike, John (9 September 2000). "KH-2 Corona". Federation of American Scientists. Retrieved 23 June 2010.
  4. ^ a b "Corona". Mission and Spacecraft Library. NASA. Archived from the original on 3 October 2007. Retrieved 26 June 2010.
  5. ^ a b Wade, Mark. "KH-2". Encyclopedia Astronautica. Archived from the original on 23 January 2013. Retrieved 26 June 2010.