Chinese Missile Destroys Satellite in 500-Mile Orbit
by David Kestenbaum
All Things Considered, January 19, 2007 · The governments of Britain, Japan and Australia are voicing concern over China’s apparent test of an anti-satellite missile. The United States says China shot down one of its own aging weather satellites last week, in a kind of target practice in low Earth orbit.
Not much information about the event has been released. But scientists say hitting a satellite from the ground takes fairly sophisticated technology.
The satellite was 500 miles above the Earth’s surface. The explosion created a cloud of debris in space, adding to the amount of “space junk” circling the Earth.
Hans Kristensen, a weapons expert at the Federation of American Scientists, says that while it has been assumed that China was working to develop such capabilities, the satellite strike still surprised him.
“I was surprised that they were able to do it,” Kristensen says.
U.S. officials say the Chinese hit the satellite with the help of a medium-range ballistic missile — most likely the DF-21.
A satellite is a fairly small thing to hit with a missile. Kristensen says the DF-21 can probably hit a spot on the ground with an accuracy of several hundred feet. But the satellite was probably close to the size of a refrigerator.
So the assumption is that the Chinese device had some sort of advanced guidance system — maybe a kind of telescope to pick out the satellite. Then, it used thrusters to steer it toward the target. The force of the collision would have destroyed the satellite.
Kristensen says that when the United States and Russia were developing anti-satellite missiles in the 1980s, hitting the target was the hard part.
The United States successfully shot down one of its own satellites in 1985. So could a Chinese missile now take out a U.S. satellite? A rule of thumb is that a missile can go to a height about half of its horizontal range. So this missile might be able to reach an altitude of 600 miles.
The Global Positioning System satellites, now in common use, are much higher, tens of thousands of miles out.
But Kristensen says there are plenty of targets lower in the atmosphere. Spy satellites tend to be very low,” he says, “because you need to get close.”
David Wright, a physicist with the Union of Concerned Scientists, has been using computer models created by NASA to estimate debris from collisions. He says the latest smash-up would have been the equivalent of a half ton of high explosives going off.
This satellite was maybe 3/4 of a ton in mass,” Wright says. “And it would have thrown off about 2 million pieces that were bigger than a millimeter in size. Sounds pretty small but at speed going a millimeter object could be deadly.”
Deadly, that is, for other satellites. The odds of the debris hitting something look small he says. But this single event probably doubled the number of pieces of space junk at its altitude range.
China’s successful test of an anti-satellite (Asat) weapon means that the country has mastered key space sensor, tracking and other technologies important for advanced military space operations. China can now also use “space control” as a policy weapon to help project its growing power regionally and globally.
Aviation Week & Space Technology first broke the news of the Chinese Asat test on aviationweek.com Jan. 17.
China performed the test Jan. 11 by destroying the aging Chinese Feng Yun 1C (FY-1C) weather satellite target at 537 mi. altitude. The attack was carried out with a kinetic kill vehicle launched by a small ballistic missile.
U.S. intelligence agencies calculated in advance that the Chinese were ready for the exercise and programmed American eavesdropping and space tracking sensors accordingly to obtain maximum information.
The White House confirmed the Aviation Week article Jan. 18 and warned China that its actions will carry ramifications. “We are concerned about it, and we’ve made it known,” says Tony Snow, the White House spokesman.
“The U.S. believes China’s development and testing of such weapons is inconsistent with the spirit of cooperation that both countries aspire to in the civil space area,” said Gordon Johndroe, U.S. National Security Council spokesman. “We and other countries have expressed our concern to the Chinese regarding this action.”
The revelation of the Asat test also sparked official condemnation or concern of the Chinese from the governments of Canada, Australia, Japan and South Korea.
The warning about ramifications comes as NASA and the Chinese space agency are continuing talks aimed at closer civil space collaboration. The Asat test will likely further undercut U.S. government enthusiasm for such scientific space cooperation, at a time when the U.S. and China are debating military space policy at the United Nations.
But China’s bold move will have greater impact on arguments by factions in the Defense Dept. and aerospace industry for increased U.S. spending on space surveillance and control measures. The Asat test will also likely spur formation of a more robust military strategy focused on China.
Many spacecraft operate in, or at least transit, the area of space where the attack occurred, and there are concerns that debris from the test could pose a hazard to these satellites. Air Force Space Command data show that when the kill vehicle impacted the target satellite, debris was ejected from the impact point at velocities of up to 1,400 mph. (2,000 fps.).
China’s growing military space capability is a key reason the Bush administration last year formed the nation’s first new national space policy in more than a decade. “The policy is designed to ensure that our space capabilities are protected in a time of increasing challenges and threats,” says Robert G. Joseph, undersecretary for arms control and international security at the U.S. State Dept. “This is imperative because space capabilities are vital to our national security and to our economic well-being,” Joseph said in an address on the policy at the National Press Club in Washington.
Although more of a “policy weapon” at this time, the Chinese Asat shows that the Chinese military can credibly threaten imaging reconnaissance and other satellites operated by the U.S., Japan, Russia, Israel and Europe.
Taiwan also operates a small imaging spacecraft that can photograph objects as small as about 10 ft. in size, a capability good enough to count cruise missiles pointed at Taiwan from the Chinese mainland.
CIA and National Reconnaissance Office (NRO) officials are especially concerned about their ability to monitor Chinese weapons developments with satellite reconnaissance because the Chinese have become so adept at camouflage.
The list of countries with space reconnaissance capability grew again last week, with the launch of Egypt’s EgyptSat 1 from the Baikonur Cosmodrome in Kazakhstan.
The CIA, National Security Agency, Defense Intelligence Agency, NASA and other government organizations have a full-court press underway to process information they collected on the Asat test, which remained highly classified last week.
The spacecraft that was destroyed was launched by the Chinese in 1999 into a Sun-synchronous circular orbit inclined 98.6 deg. The FY-1C had a 5-ft.-square main body with solar arrays spanning 27 ft.
The attack occurred at 5:26 p.m. EST Jan. 11 as the target satellite was 715 mi. from the Xichang launch site in Sichuan province. It was passing about 45 deg. above the horizon at Xichang, as the Chinese ballistic missile with the kill vehicle was launched either directly from Xichang or a site nearby.
Tracking of the target satellite was managed from a large team at the Xian Chinese space tracking control center.
The azimuth from the launch point to the target was about 346 deg., or 15 deg. west of due north. The target in orbit was heading south, so the intercept involved an extremely high-velocity, nearly head-on collision, sources said. Debris from the impact was ejected in all directions at 700-1,400 mph., tracking data indicate.
The event occurred 94 min. before sunrise at Xichang, but the target satellite was in sunlight, enabling excellent monitoring of the event by the Chinese.
Tracking cameras at Xichang had an excellent view of the intercept from the front, while cameras at China’s other major launch site at Jiuquan in the Gobi Desert had an equally good viewing angle from behind.
U.S. Air Force Defense Support Program missile warning satellites in geosynchronous orbit detected the Xichang launch of the Asat kill vehicle, and U.S. Air Force Space Command radars monitored the FY-1C orbit both before and after the exercise.
U.S. Space Command had cataloged 32 pieces of debris through Jan. 18, but it’s likely the attack left hundreds or thousands of tiny pieces of debris that could orbit for years.
The Air Force reporting on the FY-1C orbital elements have been posted once or twice daily for years, but those reports jumped to about four times per day just before the test.
The USAF radar reports all but ceased Jan. 11, then appeared to show “signs of orbital distress” when resumed temporarily a few days later. By Jan. 18, the data showed multiple debris where the FY-1C spacecraft had been before.
CHINA IS ALSO DEVELOPING A LASER Asat capability and last year illuminated a U.S. reconnaissance satellite with a laser that did no harm. “But it made us think,” Donald Kerr, NRO director, said at the time.
Aviation Week reported more than 20 years ago that the U.S. has used lasers to illuminate Chinese and then Soviet satellites to obtain engineering intelligence.
Both the U.S. and former Soviet Union maintained various Asat programs throughout the Cold War. In a 1985 controversial test, a U.S. Air Force F-15 launched a miniature kill vehicle propelled by SRAM/Altair solid rocket motors to impact and destroy the USAF Solwind science spacecraft. In more recent years, the Pentagon has spent nearly $400 million developing a much more advanced KE-Asat kinetic kill vehicle. It was never used in an Asat test, but at least three standby units were built.
The U.S. Air Force still operates the 76th Space Control Sqdn., based at Peterson AFB, Colo.–the service’s first offensive and defensive counterspace technology squadron. Mobile teams from the 76th can deploy worldwide to jam enemy satellite communications.
using KKV to directly hit such small target in rising phase, the involved techs are very complicated, not even russia has proven to master them. india? eh~
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