Discoverer 18

Discoverer 18

Operator	US Air Force/NRO
Major contractors	Lockheed
Bus	KH-2 Corona' Agena-B
Mission type	Optical reconnaissance
Launch date	7 December 1960 20:20:58 UTC
Carrier rocket	Thor DM-21 Agena-B 296
Launch site	Vandenberg LC-75-3-4
Orbital decay	2 April 1961
COSPAR ID	1960 Sigma 1
Mass	1,240 kilograms (2,700 lb)
Orbital elements
Regime	Low Earth
Inclination	81.4°
Apoapsis	535 kilometres (332 mi)
Periapsis	272 kilometres (169 mi)
Orbital period	92.6 minutes

The launch of Discoverer 18

Discoverer 18, also known as Corona 9013, was an American optical reconnaissance satellite which was launched in 1960. It was a KH-2 Corona satellite, based around an Agena-B.^[1]

The launch of Discoverer 18 occurred at 20:20:58 UTC on 7 December 1960. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-3-4 at the Vandenberg Air Force Base.^[2] Upon successfully reaching orbit, it was assigned the Harvard designation 1960 Sigma 1.

Discoverer 18 was operated in a low Earth orbit, with a perigee of 272 kilometres (169 mi), an apogee of 535 kilometres (332 mi), 81.4 degrees of inclination, and a period of 92.6 minutes.^[3] The satellite had a mass of 1,240 kilograms (2,700 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 returned in a Satellite Recovery Vehicle, which was recovered three days after the launch. The Satellite Recovery Vehicle used by Discoverer 18 was SRV-508. Following the return of its images, Discoverer 18 remained in orbit until it decayed on 2 April 1961.^[3] It was the first KH-2 satellite to complete its mission successfully.^[6]

References

1. ^ Krebs, Gunter. "KH-2 Corona". Gunter's Space Page. http://space.skyrocket.de/doc_sdat/kh-2.htm. Retrieved 26 June 2010. 
2. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. http://planet4589.org/space/log/launchlog.txt. Retrieved 26 June 2010. 
3. ^ ^{a b} McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. http://planet4589.org/space/log/satcat.txt. Retrieved 26 June 2010. 
4. ^ Wade, Mark. "KH-2". Encyclopedia Astronautica. http://www.astronautix.com/craft/kh2.htm. Retrieved 26 June 2010. 
5. ^ "Corona". Mission and Spacecraft Library. NASA. http://msl.jpl.nasa.gov/programs/corona.html. Retrieved 26 June 2010. 
6. ^ Pike, John (9 September 2000). "KH-2 Corona". Federation of American Scientists. http://www.fas.org/spp/military/program/imint/kh-2.htm. Retrieved 26 June 2010.