Discoverer 36


Discoverer 36
Mission typeOptical reconnaissance
OperatorUS Air Force/NRO
Harvard designation1961 Alpha Kappa 1
COSPAR ID1961-034A
SATCAT no.00213Edit this on Wikidata
Mission duration4 days
Spacecraft properties
Spacecraft typeKH-3 Corona
Launch mass1,150 kilograms (2,540 lb)
Start of mission
Launch date12 December 1961, 20:40 (1961-12-12UTC20:40Z) UTC
RocketThor DM-21 Agena-B 325
Launch siteVandenberg LC-75-3-4
End of mission
Decay date8 March 1962 (1962-03-09)
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude223 kilometers (139 mi)
Apogee altitude445 kilometers (277 mi)
Inclination81.1 degrees
Period91.2 minutes
The launch of Discoverer 36

Discoverer 36, also known as Corona 9029, was an American optical reconnaissance satellite which was launched in 1961. It was a KH-3 Corona satellite, based on an Agena-B rocket.[1] It was the penultimate KH-3 satellite to be launched, the last successful mission, and the most successful of the program.[2]

The launch of Discoverer 36 occurred at 20:40 UTC on 12 December 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-3-4 at the Vandenberg Air Force Base.[3] Upon successfully reaching orbit, it was assigned the Harvard designation 1961 Alpha Kappa 1. OSCAR 1, the first amateur radio satellite, was launched aboard the same rocket.[3]

Discoverer 36 was operated in a low Earth orbit, with a perigee of 223 kilometres (139 mi), an apogee of 445 kilometres (277 mi), 81.1 degrees of inclination, and a period of 91.2 minutes.[4] 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).[6] Images were recorded onto 70-millimeter (2.8 in) film, and returned in a Satellite Recovery Vehicle four days after launch.[7] The Satellite Recovery Vehicle used by Discoverer 36 was SRV-525. Once its images had been returned, Discoverer 36 remained in orbit until it decayed on 8 March 1962.[4]


  1. ^ Krebs, Gunter. "KH-3 Corona". Gunter's Space Page. Retrieved 30 June 2010.
  2. ^ Lindborg, Christina; Pike, John (9 September 2000). "KH-3 Corona". Federation of American Scientists. Retrieved 30 June 2010.
  3. ^ a b McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 30 June 2010.
  4. ^ a b McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 30 June 2010.
  5. ^ Wade, Mark. "KH-3". Encyclopedia Astronautica. Archived from the original on 18 September 2010. Retrieved 30 June 2010.
  6. ^ "Corona". Mission and Spacecraft Library. NASA. Archived from the original on 3 October 2007. Retrieved 30 June 2010.
  7. ^ "Bail Out Into Sea: Frogmen Recover Latest Capsule". Montreal, Quebec: The Gazette. Associated Press. 18 December 1961. p. 2. Retrieved 1 January 2016.