Friday October 6, 1:15 AM     Reuters

*China jamming U.S. satellites*

By Andrea Shalal-Esa

WASHINGTON (Reuters) - China has beamed a ground-based laser at U.S. spy
satellites over its territory, a U.S. agency said, in an action that
exposed the potential vulnerability of space systems that provide
crucial data to American troops and consumers around the world.

The Defence Department remains tight-lipped about details, including
which satellite was involved or when it occurred.

The Pentagon's National Reconnaissance Office Director Donald Kerr last
week acknowledged the incident, first reported by Defence News, but said
it did not materially damage the U.S. satellite's ability to collect
information.

"It makes us think," Kerr told reporters.

The issue looms large, given that U.S. military operations have rapidly
grown more reliant on satellite data for everything from targeting bombs
to relaying communications to spying on enemy nations.

Critical U.S. space assets include a constellation of 30 Global
Positioning Satellites that help target bombs and find enemy locations.
This system is also widely used in commercial applications, ranging from
car navigation systems to automatic teller machines.

The Pentagon also depends on communications satellites that relay
sensitive messages to battlefield commanders, and satellites that track
weather in critical areas so U.S. troops can plan their missions.

"Space is a much bigger part of our military posture than it used to be,
so any effort by the Chinese or anybody else to jam our satellites is
potentially a big deal," said Loren Thompson, defence analyst with the
Virginia-based Lexington Institute.

FRESH CONCERNS

Clearly, the incident sparked fresh concerns among U.S. officials and
watchdog groups about the U.S. ability to determine if satellite
problems are caused by malfunctions, weather anomalies like solar
flares, or targeted attacks.

Air Force Space Commander Gen. Kevin Chilton said it was often difficult
to know exactly what happened to satellites orbiting from 125 to 22,400
miles (200 to 36,000 km) above the earth.

"We're at a point where the technology's out there and the capability
for people to do things to our satellites is there. I'm focussed on it
beyond any single event," Chilton said.

Satellites are also vulnerable to man-made and natural events affecting
their ground stations and the links between the station and the
satellite, he told reporters last week.

Theresa Hitchens of the Centre for Defence Information cautioned against
jumping to conclusions about the Chinese incident.

Beijing may have been testing its capability to track satellites, not
damage them, Hitchens said. "We don't know their intent, and we don't
have the capability to know."

Hitchens also noted current technology made it difficult to identify
anything smaller than a baseball in the orbits where spy satellites fly,
a capability that needed to be improved.

At the same time, she said, the Pentagon would be prudent to use
lower-cost and lower-risk systems closer to earth to do some critical
tasks like surveillance and communications.

ANTI-SATELLITE WEAPONS?

Hitchens also emphasised that it would be extremely difficult to disable
a satellite with a laser -- and even U.S. scientists had not developed a
system to do that.

But there is growing concern among lawmakers about U.S. efforts to
develop such anti-satellite weapons.

House of Representatives lawmakers tried to block a planned test of
Starfire, a satellite and star tracking program, for fiscal 2007 after
learning it could also be used as an anti-satellite weapon. The funds
were reinstated only after the Air Force assured lawmakers it would be
used only for tracking.

The Chinese incident also underscored the need to develop an
international code of conduct for space. Currently, there are no
specific rules or treaties governing behaviour of the 40 countries that
operate satellites, and about a dozen countries that have launch
capability, Hitchens said.