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U. S.
intelligence agencies believe China performed the anti-satellite
(ASAT) test January 11. During the test, a kinetic kill vehicle,
launched by a ballistic missile destroyed a target orbiting
earth at an altitude of 537 mi (864 km). The Chinese test was
similar to a test of a kinetic energy ASAT weapon carried by
the U.S. in 1985, destroyed a U.S. scientific satellite in orbit
at 326 mi (525 km) altitude. The destruction of the weather
satellite left considerable space debris in a heavily crowded
orbit around 900km, used by many commercial, scientific and
military satellites.
The target of the recent Chinese test was identified as the
Feng Yun 1C spacecraft, an aging Chinese weather satellite.
The exercise signifies a major new Chinese military capability.
According to intelligence reports, China tested laser countermeasures
to blind US reconnaissance satellites passing over China. It
was reported that for the past several months, Chinese lasers
have been "illuminating" US spy satellites. This recent
demonstration signifies the maturity and breadth of China's
military capabilities in space. According to Aviation Week,
which broke the story last Wednesday (Jan. 17, 2007) the current
Chinese capability is more of a "policy weapon" at
this time, but the test shows that the Chinese military can
threaten the imaging reconnaissance satellites operated by the
U. S., Japan, Russia, Israel and Europe.
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"The point is that live ASAT weapons testing in space
- be it at a low earth orbit (LEO), a medium earth orbit (MEO),
or a geostationary earth orbit (GEO) - has a potential to damage
or destroy a lot more than merely the intended target,"
says Marco Caceres, lead analyst for Teal Group's World Space
Systems Briefing. "The event likely added hundreds of trackable
debris objects and tens of thousands of small particles to the
growing problem," he said. According to estimates by the
TEAL group, there are about 175-200 LEO commercial satellites
currently in operation, in addition to military and scientific
satellites and the International Space Station (ISS). David
Wright, co-director of the Global Security Program at the Union
of Concerned Scientists, adds that the altitude of this test
was a particular concern, because of the low atmospheric density
at that altitude, half of the debris larger than one centimeter
would remain in orbit for a decade or longer.
This thrust will undoubtedly intensify the US Pentagon and
Congressional interest in "space control". China's
growing military space capability is one major reason the Bush
Administration last year formed the nation's first new National
Space Policy in ten years.
Because kinetic energy ASAT weapons destroy satellites by colliding
with them at very high speeds, their use creates large amounts
of space debris, which can remain in orbit for very long times
and threaten other satellites. The Chinese satellite that was
destroyed had a mass of 750 kilograms and was orbiting at an
altitude of 850 kilometers. The collision would be expected
to completely fragment the satellite into millions of pieces
of debris: nearly 800 debris fragments of size ten centimeters
or larger, nearly 40,000 debris fragments with size between
one and ten centimeters, and some 2 million fragments of size
one millimeter or larger. At the very high speeds these debris
particles would have, particles as small as one millimeter can
be very destructive. While shielding on satellites can help
protect against small particles, most satellites do not carry
such shielding. Moreover, shielding is not effective against
debris larger than about one centimeter in size.
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