Discoverer 25

Summary

Discoverer 25, also known as Corona 9017, was an American optical reconnaissance satellite which was launched in 1961. It was the fifth of ten Corona KH-2 satellites, based on the Agena-B.[1]

Discoverer 25
Mission typeOptical reconnaissance
OperatorUS Air Force/NRO
Harvard designation1961 Xi 1
COSPAR ID1961-014A Edit this at Wikidata
SATCAT no.00108Edit this on Wikidata
Mission duration2 days
Spacecraft properties
Spacecraft typeCorona KH-2
BusAgena-B
ManufacturerLockheed
Launch mass1,150 kilograms (2,540 lb)
Start of mission
Launch date16 June 1961, 23:02:52 (1961-06-16UTC23:02:52Z) UTC
RocketThor DM-21 Agena-B 303
Launch siteVandenberg LC-75-1-1
End of mission
Decay date12 July 1961 (1961-07-13)
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude223 kilometers (139 mi)
Apogee altitude361 kilometers (224 mi)
Inclination82.1 degrees
Period90.4 minutes
 

The launch of Discoverer 25 occurred at 23:02 UTC on 16 June 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-1-1 at the Vandenberg Air Force Base.[2] Upon successfully reaching orbit, it was assigned the Harvard designation 1961 Xi 1.

Discoverer 25 was operated in a low Earth orbit, with a perigee of 223 kilometres (139 mi), an apogee of 361 kilometres (224 mi), 82.1 degrees of inclination, and a period of 90.4 minutes.[3] The satellite had a mass of 1,150 kilograms (2,540 lb),[4] 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).[5] Images were recorded onto 70-millimeter (2.8 in) film, and returned in a Satellite Recovery Vehicle two days after launch. The Satellite Recovery Vehicle used by Discoverer 25 was SRV-510. Once its images had been returned, Discoverer 25's mission was complete, and it remained in orbit until it decayed on 12 July 1961.[3]

The Satellite Recovery Vehicle was designed to be recovered in mid-air by a Fairchild C-119J Flying Boxcar aircraft. As SRV-510 descended, the C-119J was unable to capture it, and the capsule had to be recovered at sea after it landed. The film it returned was affected by streaks across images.[4]

References edit

  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. ^ a b McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 26 June 2010.
  4. ^ a b Wade, Mark. "KH-2". Encyclopedia Astronautica. Archived from the original on 23 October 2012. Retrieved 26 June 2010.
  5. ^ "Corona". Mission and Spacecraft Library. NASA. Archived from the original on 3 October 2007. Retrieved 26 June 2010.