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China destroys Feng Yun weather satellite with anti-satellite missile

Science - Space

On January 11, 2007, at about 5:28 p.m. EST, China destroyed one of its aging weather satellites—Feng Yun (FY-1C)—with a ground-based, modified medium-range ballistic missile equipped with a kinetic kill projectile aboard—generally called an ASAT (anti-satellite) missile system.

The developing story was reported by Craig Covault of Aviation Week & Space Technology on January 17, 2007. The major news agencies such as Fox News and CNN confirmed the story on January 19, 2007.

The Feng Yun satellite, which was launched in 1999, was in a polar orbit about the Earth, at a mean altitude of 537 miles (864 kilometers). The Chinese launch of the ASAT missile occurred at or near the Xichang Space Launch Center (XSPL), which is about 40 miles (64 kilometers) northwest of Xichang City (Sichuan Province, China). When it was destroyed, Feng Yun was reportedly at a 530-mile (853-kilometer) altitude and four degrees west of Xichang City. Afterwards, sensing devices operated by U.S. intelligence agencies (such as U.S. Air Force Space Command) confirmed that the weather satellite was no longer in its original orbit.

A kinetic kill (or kinetic energy kill) projectile is the last stage of an interceptor weapon. Kinetic energy of an object is the additional energy that an object possesses due to its velocity. In physics, kinetic energy is defined as the amount of work necessary to accelerate a body of a particular mass from rest (zero velocity) to a specific velocity. A projectile keeps this kinetic energy unless its speed changes—such as when it impacts a satellite either directly or indirectly when it is exploded near the target.

Because the event was not reported by the Chinese government before it was carried out, the United States, Canada, Australia, and other countries have voiced informal concerns and levied formal protests against the action of the Chinese government. Most countries are concerned that by not reporting the action beforehand, the Chinese are placing healthy satellites at potential risk from space debris left in orbit, along with the possible re-entry of debris onto populated areas on the Earth. Such action, whether reported or not, also places other countries’ satellites in jeopardy by the mere fact that they can be destroyed.

The United States and Russia (former Soviet Union) have developed programs (starting in the 1950s) with the capability to destroy/disable orbiting satellites in similar ways to the Chinese. The United States has used such technology to test its ability to disable satellites. One such event occurred on September 13, 1985, when an ASM-135 ASAT missile disabled a P78-1 research satellite in orbit about the Earth.

The Aviation Week & Space Technology article (“Chinese Test Anti-Satellite Weapon”) appears at: http://www.avweek.com/avnow/news/channel_awst_story.jsp?id=news/CHI01177.xml.

 

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