Discoverer 27
Encyclopedia
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
. 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
. 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.
Discoverer 27 was designed to operated in a low Earth orbit
, and had a mass of 1150 kilograms (2,535.3 lb). It was equipped with a frame camera with a focal length
of 76 millimetres (3 in), which had a maximum resolution of 140 metres (459.3 ft). The camera would have recorded images onto 127 millimetres (5 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.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
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
RM-81 Agena
The RM-81 Agena was an American rocket upper stage and satellite support bus which was developed by Lockheed initially for the canceled WS-117L reconnaissance satellite program...
. 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
Thor-Agena
Thor-Agena was a series of orbital launch vehicles. The rockets used Thor first stages and Agena second stages. They are thus cousins of the more famous Thor-Deltas, which founded the Delta rocket family. The first attempted launch of a Thor-Agena was in January 1959...
rocket was used, flying from Launch Complex 75-3-4 at the Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
. As it ascended towards orbit, the rocket's pitch became anomalous, causing the range safety officer
Range Safety Officer
In the field of rocketry, Range Safety Officer is a generic term referring to an individual who monitors the performance of rockets in flight, and who is responsible for their remote destruction if it should be judged that they pose a hazard...
to command the rocket to self-destruct by means of its flight termination system.
Discoverer 27 was designed to operated in a low Earth orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...
, and had a mass of 1150 kilograms (2,535.3 lb). It was equipped with a frame camera with a focal length
Focal length
The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus...
of 76 millimetres (3 in), which had a maximum resolution of 140 metres (459.3 ft). The camera would have recorded images onto 127 millimetres (5 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.