January 28, 2010

Debris Poses Great Risk To Spacecraft

The major powers of the world are being called upon to clean up space "litter" that is becoming increasingly dangerous for spacecraft, the head of the U.S. Strategic Command said on Wednesday.

According to Reuters, former astronaut and Air Force General Kevin Chilton told an Israeli audience that the U.S. has documented more than 15,000 items, including jettisoned rockets, shuttle detritus, and pieces of destroyed satellites floating in space, reported Reuters.

"The estimation is that these numbers could grow upward of 50,000 in total numbers in the not-too-distant future," he said.

Chilton also added that such debris could leave low-earth orbit "uninhabitable to man or machine."

He said that the amount of debris has increased exponentially because of events such as China's 2007 shooting down of a defunct satellite, and last year's collision of an old Russian military satellite and a telecoms satellite owned by Iridium.

In 2008, the U.S. blew up a target satellite using the Aegis missile interceptor, which many perceived as an attempt to stay up to par with China.  The Aegis currently serves as the core of a planned U.S. ballistic shield for Eastern Europe.

The recent increase of debris has caused a "cascade" to appear, whereby clutter results in collisions, creating more debris, said Chilton.

He urged major powers to agree on a "responsible space operation," improve their spacecraft to cut back on new debris, and share data on possible risks.

"The U.S. has quite an extensive array of sensors ... but even that is not enough," he said in his address to the Fisher Institute for Air & Space Strategic Studies, near Tel Aviv.

"We need to improve our space surveillance capabilities."

However, Chilton noted that containment is the only option available for the time being without a way to dispose of it properly.

"Today, the way we eliminate space debris is we wait for it to come down" and burn up on reentry through the atmosphere, he said.


Image Caption: A Beehive of Satellites - The launch of the first artificial satellite by the then Soviet Union in 1957 marked the beginning of the utilization of space for science and commercial activity. During the Cold War, space was a prime area of competition between the Soviet Union and the U.S. In 1964 the first TV satellite was launched into a geostationary orbit to transmit the Olympic games from Tokyo. Later, Russian launch activities declined while other nations set up their own space programs. Thus, the number of objects in Earth orbit has increased steadily -- by 200 per year on average. The debris objects shown in the images are an artist's impression based on actual density data. However, the debris objects are shown at an exaggerated size to make them visible at the scale shown. (ESA)


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