Discoverer 35

Discoverer 35, also known as Corona 9028, was an American optical reconnaissance satellite which was launched in 1961. It was the last of ten Corona KH-2 satellites, based on the Agena-B.^[1]

The launch of Discoverer 35

Discoverer 35

Mission type	Optical reconnaissance
Operator	US Air Force/NRO
Harvard designation	1961 Alpha Zeta 1
COSPAR ID	1961-030A
SATCAT no.	00201
Mission duration	1 day
Spacecraft properties
Spacecraft type	Corona KH-2
Bus	Agena-B
Manufacturer	Lockheed
Launch mass	2,100 kilograms (4,600 lb)
Start of mission
Launch date	15 November 1961, 21:23 (1961-11-15UTC21:23Z) UTC
Rocket	Thor DM-21 Agena-B 326
Launch site	Vandenberg LC-75-3-4
End of mission
Decay date	3 December 1961 (1961-12-04)
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Perigee altitude	233 kilometers (145 mi)
Apogee altitude	247 kilometers (153 mi)
Inclination	81.6 degrees
Period	89.3 minutes
Discoverer ← Discoverer 34 Discoverer 36 → Corona KH-2 ← Corona 9027

The launch of Discoverer 35 occurred at 21:23 UTC on 15 November 1961. 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 1961 Alpha Zeta 1.

Discoverer 35 was operated in a low Earth orbit, with a perigee of 233 kilometres (145 mi), an apogee of 247 kilometres (153 mi), 81.6 degrees of inclination, and a period of 89.3 minutes.^[3] The satellite had a mass of 2,100 kilograms (4,600 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 just over a day after launch.^[4] The Satellite Recovery Vehicle used by Discoverer 35 was SRV-523.^[2] The SRV was successfully recovered. Apart from the presence of some emulsion on the images it returned, Discoverer 35 completed its mission successfully. It subsequently remained in orbit until it decayed on 3 December 1961.^[3]