Informal notes
Military/spy
satellites
by Doresa Banning
September 12,
2001
Definition of a man-made or artificial satellite:
A manmade or artificial satellite is a specialized wireless receiver/transmitter that is launched by a rocket and placed in orbit around the earth.
Types of orbits:
Geostationary or geosynchronous or synchronous orbits orbits at an altitude of about 33,000 km in which the satellite is always positioned over the same spot on Earth. Each revolution takes 24 hours. A single geostationary satellite can ³see² approximately 40 percent of the earth¹s surface.
Sun synchronous orbit orbits in which the satellite always passes over the same region at the same local sun time.
Low earth orbits (LEOs) orbits at an altitude of 500 to 2,000 km above the Earth¹s surface; an LEO satellite system employs a large fleet of ³birds,² each in a circular orbit at a constant altitude of a few hundred miles. The orbits take the satellites over, or nearly over, the geographic poles. Each revolution takes approximately 90 minutes to a few hours.
Medium earth orbits (MEOs) orbits at an altitude of 8,000 to 20,000 km above the Earth¹s surface
What all satellites have in common:
€ Metal or composite
frame and body, usually known as the bus
€ Source of
power (usually solar cells, on newer designs fuel cells) and batteries
for storage
€ An onboard
computer to control and monitor the different systems
€ Radio system
and antenna, at the least a radio transmitter/receiver
€ Attitude control rol of U.S. space
reconnaissance.
1962: More advanced versions of the CORONA satellite are launched.
1962: Early signals intelligence (SIGINT) satellites are launched by the USAF to ³sniff² adversary radars. SIGINT involves listening in on adversary communications, missile telemetry, radar emissions and other electronic systems. They transferred signals to ground stations for analysis. NRO has taken over the USAF¹s SIGINT satellite activity. The U.S. Navy orbited their own SIGINT satellites.
May 25, 1972: The last CORONA is launched. The last CORONAs offered resolutions of 6 to 10 feet.
1976: The first KH-11 electronic imaging satellite was put into orbit and transmitted imagery to ground stations through relay satellites. KH-11s operate in low altitude, sun synchronous orbits. Imagery is obtained by a solid-state charge coupled device array. Newer KH-11are believed to have infrared and optical imaging capabilities. Resolution is estimated at 6 inches or better. They¹re limited by darkness and bad weather.
1994: A U.S. decision allowed technology developed for spy satellites to be used commercially.
1995: Details on the CORONA program and 800,000 images obtained by CORONA satellites were released to the public.
March 2001: The NRO moves toward a Future Imagery Architecture series of satellites, as aerospace companies covertly recruit engineers to build these satellites. Equipped with powerful telescopes and radar, these satellites are expected to form the backbone of U.S. intelligence for several decades. The satellites will be farther out in space and harder to detect than the massive spy probes that currently orbit the Earth. They will also be able to fly over and take pictures of military compounds anywhere in the world, in darkness or through cloud cover, with far more frequency. With a bigger constellation of satellites, the probes will be able to revisit and take pictures of an area more frequently than the current versions.
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