Thor Agena B with Discoverer 36 lift-off (Dec

Discoverer 36, also known as Corona 9029, was an American optical

reconnaissance satellite A reconnaissance satellite or intelligence satellite (commonly, although unofficially, referred to as a spy satellite) is an Earth observation satellite or communications satellite deployed for military or intelligence applications. The ...

which was launched in 1961. It was a KH-3 Corona satellite, based on an Agena-B rocket. It was the penultimate KH-3 satellite to be launched, the last successful mission, and the most successful of the program. The launch of Discoverer 36 occurred at 20:40 UTC on 12 December 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-3-4 at the Vandenberg Air Force Base. Upon successfully reaching orbit, it was assigned the

Harvard designation Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

1961 Alpha Kappa 1.

OSCAR 1 OSCAR I (aka OSCAR 1) is the first amateur radio satellite launched by Project OSCAR into low Earth orbit. OSCAR I was launched December 12, 1961, by a Thor-DM21 Agena B launcher from Vandenberg Air Force Base, Lompoc, California. The satellite, ...

, the first amateur radio satellite, was launched aboard the same rocket. Discoverer 36 was operated in a

low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never mor ...

, with a

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

of , an

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

of , 81.1 degrees of

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

, and a period of 91.2 minutes. The satellite had a mass of , and was equipped with a panoramic camera with a

focal length The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative foca ...

of , which had a maximum resolution of . Images were recorded onto film, and returned in a

Satellite Recovery Vehicle A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...

four days after launch. The Satellite Recovery Vehicle used by Discoverer 36 was SRV-525. Once its images had been returned, Discoverer 36 remained in orbit until it decayed on 8 March 1962.

References

Spacecraft launched in 1961 Spacecraft which reentered in 1962 {{US-spacecraft-stub