Discoverer 27

Discoverer 27

Operator	US Air Force/NRO
Major contractors	Lockheed
Bus	KH-5 Argon Agena-B
Mission type	Optical reconnaissance
Launch date	21 July 1961 22:35 UTC
Carrier rocket	Thor DM-21 Agena-B 322
Launch site	Vandenberg LC-75-3-4
Mission duration	Failed to orbit
Mass	1,150 kilograms (2,500 lb)
Orbital elements
Regime	Low Earth (planned)

The launch of Discoverer 27

Discoverer 27, also known as Corona 9020A, was an American area survey optical reconnaissance satellite which was launched in 1961, but failed to achieve orbit. It was a KH-5 Argon satellite, based around an Agena-B.^[1] It was the fourth KH-5 to be launched, the second consecutive KH-5 launch failure, and the fourth consecutive KH-5 mission failure.

The launch of Discoverer 27 occurred at 22:35 UTC on 21 July 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-3-4 at the Vandenberg Air Force Base.^[2] As it ascended towards orbit, the rocket's pitch became anomalous, causing the range safety officer to command the rocket to self-destruct by means of its flight termination system.^[3]

Discoverer 27 was designed to operated in a low Earth orbit, and had a mass of 1,150 kilograms (2,500 lb).^[4] It was equipped with a frame camera with a focal length of 76 millimetres (3.0 in), which had a maximum resolution of 140 metres (460 ft).^[5] The camera would have recorded images onto 127-millimetre (5.0 in) film, which would have been returned in a Satellite Recovery Vehicle, before the satellite ceased operations. The Satellite Recovery Vehicle carried by Discoverer 27 was SRV-524.^[4]

References

1. ^ Krebs, Gunter. "KH-5 Argon (Agena-B based)". Gunter's Space Page. http://space.skyrocket.de/doc_sdat/kh-5_ab.htm. Retrieved 22 June 2010. 
2. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. http://planet4589.org/space/log/launchlog.txt. Retrieved 22 June 2010. 
3. ^ Lindborg, Christina (9 September 2000). "KH-5 Argon". Federation of American Scientists. http://www.fas.org/spp/military/program/imint/kh-5.htm. Retrieved 22 June 2010. 
4. ^ ^{a b} Wade, Mark. "KH-5". Encyclopedia Astronautica. http://www.astronautix.com/craft/kh5.htm. Retrieved 22 June 2010. 
5. ^ "Corona". Mission and Spacecraft Library. NASA. http://msl.jpl.nasa.gov/programs/corona.html. Retrieved 22 June 2010.