Discoverer 31

Discoverer 31

Operator	US Air Force/NRO
Major contractors	Lockheed
Bus	KH-3 Corona''' Agena-B
Mission type	Optical reconnaissance
Launch date	17 September 1961 21:00 UTC
Carrier rocket	Thor DM-21 Agena-B 324
Launch site	Vandenberg LC-75-1-1
Mission duration	2 days
Orbital decay	26 October 1961
COSPAR ID	1961 Alpha Beta 1
Mass	1,150 kilograms (2,500 lb)
Orbital elements
Regime	Low Earth
Inclination	82.7°
Apoapsis	380 kilometres (240 mi)
Periapsis	233 kilometres (145 mi)
Orbital period	90.7 minutes

The launch of Discoverer 31

Discoverer 31, also known as Corona 9024, was an American optical reconnaissance satellite which was launched in 1961. It was a KH-3 Corona''' satellite, based around an Agena-B.^[1]

The launch of Discoverer 31 occurred at 21:00 UTC on 17 September 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 Alpha Beta 1.

Discoverer 31 was operated in a low Earth orbit, with a perigee of 233 kilometres (145 mi), an apogee of 380 kilometres (240 mi), 82.7 degrees of inclination, and a period of 90.7 minutes.^[3] The satellite had a mass of 1,150 kilograms (2,500 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-millimetre (2.8 in) film, and were to have been returned in a Satellite Recovery Vehicle. The Satellite Recovery Vehicle carried aboard Discoverer 31 was SRV-552. During the spacecraft's thirty-third orbit, the attitude control and power systems malfunctioned, and as a result Discoverer 31 was unable to complete its mission or return images.^[4][6] It decayed from orbit on 26 October 1961.^[3]

References

1. ^ Krebs, Gunter. "KH-3 Corona". Gunter's Space Page. http://space.skyrocket.de/doc_sdat/kh-3.htm. Retrieved 29 June 2010. 
2. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. http://planet4589.org/space/log/launchlog.txt. Retrieved 29 June 2010. 
3. ^ ^{a b} McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. http://planet4589.org/space/log/satcat.txt. Retrieved 29 June 2010. 
4. ^ ^{a b} Wade, Mark. "KH-3". Encyclopedia Astronautica. http://www.astronautix.com/craft/kh3.htm. Retrieved 29 June 2010. 
5. ^ "Corona". Mission and Spacecraft Library. NASA. http://msl.jpl.nasa.gov/programs/corona.html. Retrieved 29 June 2010. 
6. ^ Lindborg, Christina; Pike, John (9 September 2000). "KH-3 Corona". Federation of American Scientists. http://www.fas.org/spp/military/program/imint/kh-3.htm. Retrieved 29 June 2010.