China has shown it can href="http://www.defensetech.org/archives/003181.html">destroy a
satellite in orbit. What could the U.S. do to stop Beijing, if it
decided to attack an American orbiter next? Short answer: nothing.
src="https://www.defensetech.org/images/china_satellite.jpg"
width="220" height="168" hspace="10" vspace="5" />It takes about 20
minutes to fire a ballistic missile into space, and have its "kill
vehicle" strike a satellite at hypersonic speed -- over 15,000 miles
per hour -- in low-earth orbit. That's far too quick for anything in
the American arsenal to respond, in time. There's "no possibility of
shielding" a relatively-fragile satellite against such a strike. "And
it is impractical [for a satellite] to carry enough fuel to maneuver
away even if you had specific and timely warning of an attack," href="http://www.cdi.org">Center for Defense Information analyst
Theresea Hitchens notes.
The American military today counts on its satellites to relay orders,
guide troops across battlefields, and spy on enemy hideouts. The U.S.
Air Force's primer for href="http://www.defensetech.org/archives/001133.html ">war in
space -- "href="http://www.dtic.mil/doctrine/jel/service_pubs/afdd2_2_1.pdf">Doctrine
Document 2-2.1: Counterspace Operations" -- lists a number of
measures that can be taken to protect American assets in orbit,
including "deploying satellites into various orbital altitudes and
planes" and "employing frequency-hopping techniques to complicate
jamming." But those tactics are used to preserve the U.S. satellite
constellation as a whole. None of them could save a single American
orbiter against a direct attack. "Physical hardening of structures
mitigates the impact of kinetic effects, but is generally more
applicable to ground-based facilities than to space-based systems due
to launch-weight considerations," the Air Force document notes.
"Maneuver[ing] is limited by on-board fuel constraints, orbital
mechanics, and advanced warning of an impending attack. Furthermore,
repositioning satellites generally degrades or interrupts their
mission."
With today's conventional defenses proving so impotent, expect a new
push within the U.S. military for more exotic countermeasures. The href=" http://www.defensetech.org/archives/001347.html">Airborne
Laser is a modified 747 that's being designed to blast missiles
out of the sky, href=" http://www.defensetech.org/archives/003157.html">as soon as they
leave they launch pad; the jet's first flight test in expected in
2009, after years and years of delays. The href="http://www.military.com/soldiertech/0,14632,Soldiertech_KEI,,00.html">Kinetic
Energy Interceptor is a long-range, non-explosive missile, meant
for the same task. But the weapon "exists mostly on paper, and
couldn't be operational before 2014," Defense Tech's David Axe noted
recently.
The U.S. could also try to destroy an anti-satellite missile, before
it took off. Over the last several years, momentum has been building
in the Pentagon for the ability to conduct "href="http://www.defensetech.org/archives/003096.html">Prompt Global
Strikes," hitting anywhere on Earth, in an hour or less. But
near-term PGS plans -- using modified Trident ballistic missiles --
have been put
on hold, for fears that such an attack could href="http://www.defensetech.org/archives/002465.html">start World War
III, in the process. Destroying a satellite is as clear an act of
war as there can be, however. Perhaps those Trident attacks will now
be seen as worth the risk.
In the meantime, href="http://GlobalSecurity.org">GlobalSecurity.org director John
Pike figures the Chinese will continue to test their satellite-killing
weapons. It takes a dozen or more trials before a strategic weapon
like this is deemed reliable enough to be considered operational. "So
expect one or two more tests like this every year, for a long time,"
he says.
The Chinese test, now href="http://www.nytimes.com/reuters/washington/politics-china-usa-satellitekiller.html?">confirmed
by the National Security Council, would be the first successful
anti-satellite weapons trial since 1985, when the United States used
an F-15 and a
kill vehicle to destroy the href="http://www.astronautix.com/craft/solwind.htm">Solwind
research satellite. And that trial was dangerous -- not just for its
target, but for nearly everything orbiting in space, Hitchens notes.
Even small pieces of space debris can be lethal to spacecraft. The '85
test "resulted in more than 250 pieces of debris, the last of which
deorbited in 2002."
The Chinese trial could "lead to nearly 800 debris fragments of size
10 cm or larger, nearly 40,000 debris fragments with size between 1
and 10 cm, and roughly 2 million fragments of size 1 mm or larger,"
the Union of Concerned Scientists'
David Wright notes on the href="http://www.armscontrolwonk.com/1359/chinese-test-asat#comment ">Arms
Control Wonk blog. "Roughly half of the debris fragments with
size 1 cm or larger would stay in orbit for more than a decade."
"This raises an interesting public policy question because we are so
much more dependent on commercial and military satellites that the
ASAT [anti-satellite] options available to us are much more
complicated than those available to the Chinese," adds Jeffrey Lewis.
"This
is a race that favors them, unfortunately."