The United States relies on spy satellites for intelligence, including about China's expanding military, and had refused previous calls for a permanent ban on such tests in space.

The test, which was reported by US officials, would show that spy satellites "are now potentially vulnerable to Chinese destruction," said Lance Gatling, an aerospace consultant based in Tokyo.

"Without announcing it, they are making a clear statement that they intend to pursue such a program at their convenience and they're willing to take some significant heat to do so," he said.

"If you think of the Beijing Olympics and trade talks and everything that's coming up, it's not unprovocative."

The United States led criticism of the test, which also triggered concern in Japan and India, Asia's two other main space powers, which have often had tense relations with China.

But Zhu Feng, director of the international security program at Peking University, said the apparent test was a natural part of China's growing profile and called the international criticism an overreaction.

"Beijing now is rising so it's also natural, I think, for Beijing to try to make some of the economic achievements spill over to the military," he said.

China is "still very much weaker than the US and Russia in such military capabilities, so it's kind of a strategy of catch-up where it would not like to be lagging so far behind," he said.

"We are also a power, we also have very big, legitimate concerns in the security field. So you cannot say, 'Okay, Beijing is a rising power (but) Beijing has no right to advance when it's security is concerned.'"

The Chinese government has not directly commented on the reported test but said that its space program is not a threat.

The United States, however, has voiced concern not only over the political implications of the test but also about debris hitting satellites or the manned International Space Station.

Gatling estimated that debris from the destroyed Chinese weather satellite was travelling at some 17,000 miles an hour (27,000 kilometers an hour) and would stay in space for three to five years.

He said Japan, European nations and possibly India had the know-how to carry out similar tests, which he described at a technical level as the "outer space equivalent of a car bomb."

"It raises the stakes in what some people see as a kind of inevitable progress toward a militarization of space. This has been a threshold that most countries are not willing to talk about," he said.

Japan has launched spy satellites since 2003, aimed in part at monitoring communist neighbor North Korea, and last year moved to ease its own restrictions on the military use of space.

Yasunori Matogawa, a professor of space engineering at the Institute of Space and Astronautical Science, part of the Japan Aerospace Exploration Agency, predicted more calls in Tokyo to develop its own capabilities.

"The test was shocking more in the symbolic sense than in the actual damage of the space debris," he said.

"The test didn't come at the best time for Japan. It may fuel the argument that Japan should develop space technology for national defense, especially as it came in the midst of the North Korean nuclear crisis."

earlier related report
UCS Statement On Chinese Anti-Satellite Test
Washington (SPX) Jan 22 - The following statement was released Friday by David Wright, co-director of the Global Security Program at the Union of Concerned Scientists: "China's Jan. 11 test of a kinetic energy anti-satellite (ASAT) weapon apparently destroyed a defunct Chinese satellite by slamming into it.

UCS strongly opposes the development, testing, and deployment of such ASAT weapons by all countries. Space is uniquely well suited to a wide range of scientific, civilian, and military purposes.

Debris produced by the testing or use of kinetic energy ASATs threatens the use of space for these purposes. China's test merely demonstrates what we already knew: satellites are by nature vulnerable to attack.

Moreover, the development and use of ASAT weapons threatens to undermine relationships and fuel military tensions between space-faring nations.

For these reasons, we:

+ urge China to abandon destructive ASAT weapons testing;
+ urge the United States not to resume an ASAT test program;
+ call on the United States to enter international discussions to develop rules guiding the use of space and to ban the testing and use of destructive ASAT weapons.

China and other countries have long called for discussions to develop a legal framework for space conduct, but the United States has been unwilling to join them. As a result, China's ASAT test was legal.

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.

The altitude of this test was a particular concern for two reasons. First, 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.

Moreover, the orbital region around 900 kilometers is very heavily used by satellites for both civil and military uses, which are threatened by the added debris.

The Chinese test was similar to the U.S. test of a kinetic energy ASAT weapon that destroyed a U.S. scientific satellite in September 1985, the last time such a test was conducted by any country. The U.S. test took place at 525 kilometers altitude."

Related Links
Read More About the Chinese Space Program
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