Vortex, previously known as Chalet, was a class of

spy 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 ...

operated by the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

during the 1980s and 1990s to collect

signals intelligence Signals intelligence (SIGINT) is the act and field of intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly u ...

(SIGINT) from high Earth orbit. The Vortex satellites were operated by the

National Reconnaissance Office The National Reconnaissance Office (NRO) is a member of the United States Intelligence Community and an agency of the United States Department of Defense which designs, builds, launches, and operates the reconnaissance satellites of the U.S. f ...

for the

United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

and listened to radio transmissions originating from Earth or space. The intercepted data is believed to have been fed into and analyzed by the

National Security Agency The National Security Agency (NSA) is an intelligence agency of the United States Department of Defense, under the authority of the director of national intelligence (DNI). The NSA is responsible for global monitoring, collection, and proces ...

ECHELON Echelon may refer to: * A level formation ** A level or rank in an organization, profession, or society ** A military sub-subunit smaller than a company but larger than a platoon ** Echelon formation, a step-like arrangement of units * ECHELO ...

system. The satellites each had a mass of approximately 1,800

kilogram The kilogram (also spelled kilogramme) is the base unit of mass in the International System of Units (SI), equal to one thousand grams. It has the unit symbol kg. The word "kilogram" is formed from the combination of the metric prefix kilo- (m ...

s and are operated from non-stationary

geosynchronous orbit A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital ...

s. Each reportedly carried a 38-meter-diameter umbrella-like reflecting dish to collect radio signals from Earth. At least six launch attempts were made of Chalet/Vortex satellites between 1978 and 1989. The Chalet/Vortex satellites replaced the older generation of Canyon satellites, and were superseded by the larger, more capable Mercury satellites.

Launches

:'' * – The rockets used for the first three launches also included Transtages, however it was considered an integral component of the rocket, and an additional upper stage for launches.''

References

*Richelson, Jeffrey T. ed. ''U.S. Military Uses of Space, 1945-1991 Vol 1, Guide.'' National Security Archive. 1991.

External links

Vortex satellite drawing
from

Federation of American Scientists The Federation of American Scientists (FAS) is an American nonprofit global policy think tank with the stated intent of using science and scientific analysis to attempt to make the world more secure. FAS was founded in 1945 by a group of scient ...

List of SIGINT satellites
from FAS
Jonathan's space report No 369
(1998-08-22)

from

Encyclopedia Astronautica The ''Encyclopedia Astronautica'' is a reference web site on Space exploration, space travel. The encyclopedia includes 79,433 articles with 13,741 illustrations, a comprehensive catalog of missiles, spacecraft, space technology, astronauts, an ...

Launch log
from

Jonathan's Space Report ''Jonathan's Space Report'' (JSR) is a newsletter about the Space Age hosted at Jonathan's Space Page. It is written by Jonathan McDowell, a Center for Astrophysics Harvard & Smithsonian astrophysicist. It is updated as McDowell's schedule pe ...

{{US Reconnaissance Satellites National Reconnaissance Office satellites Signals intelligence satellites Military equipment introduced in the 1970s

Launches

See also

References

External links