IN A remote valley in New Mexico’s Manzano Mountains, the US is tooling up
for war. Here, in a four-storey building with walls more than a metre thick, it
runs a secret particle-beam project. The weapons it’s developing will never be
used on Earth because they only work in a vacuum. But that’s no
problem—the idea is to fire them in space.
Once, space was empty and there was nothing there worth fighting for. Now
it’s teeming with valuable equipment and tensions are mounting. The US believes
a war in space is a virtual certainty—just last month defence secretary
Donald Rumsfeld announced plans for upgrading its military presence there.
Russia and China are also preparing for combat. And while there are no offensive
weapons in orbit today, there’s nothing to stop nations from putting them there
tomorrow. True, particle beams and other sophisticated weapons are at least a
decade away. But some space weapons are so simple that dozens of nations are
already capable of building them.
Military strategists have been thinking about orbital combat since the launch
of Sputnik 1 in 1957. For the first few years of the space race, their ideas
were hopelessly impractical and neither side sent weapons into
space—although cosmonauts carried handguns in case of an emergency landing
on enemy soil. But soon they began to design, build and test various pieces of
anti-satellite (ASAT) weaponry. The US focused on guided missiles, launched from
the air and designed to ram the target directly. The Soviets preferred “killer
satellites”—orbiting spacecraft armed with shrapnel charges that could
disable enemy craft. Both sides also dabbled in nuclear warheads. All were
decommissioned without being fired in anger.
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The end of the cold war killed off most of the systems, but the threat of
space war hasn’t gone away. In fact, it’s worse than ever. Occupation of space
is no longer a two-sided affair. Any government, private organisation—or
terrorist group—can buy off-the-shelf satellites and launch them for a few
million dollars apiece. Space has become valuable territory, both commercially
and strategically. Many nations rely on it for intelligence, and space is
teeming with privately owned communications satellites. Taken together these
have enormous potential to cause offence. No nation likes to be spied on, and
some governments see TV satellites as a weapon of cultural aggression against
which defensive measures are justified. Some time soon, someone will be tempted
to have a pop.
Analysts agree that the first move will probably be a ground-based electronic
assault on a satellite. Some say this kind of attack has already happened. A
British military communications satellite was reportedly kidnapped and driven
off course by hackers, though officials denied it. Nation states have also been
getting in on the act. The pro-government Saudi newspaper Al-Watan has
been running a series of articles on communications satellites, in which it
accuses broadcasters of spreading “political sedition”. The newspaper advocates
silencing the offending satellites. And the government of Nauru has accused its
neighbour Indonesia of jamming a commercial satellite in orbit over its
territory. Indonesia denies the charge.
Jamming a satellite hardly constitutes an act of war, but a more aggressive
approach is technically possible and also desirable—the threat of physical
damage has always been a useful negotiating tool. The trouble is there’s little
to stop threats from escalating into violence. Just like the high seas, space is
a region beyond national sovereignty. While we have treaties banning weapons of
mass destruction in orbit, international law has nothing to say about ordinary
space weaponry.
What’s more, the fact that space-based technologies are vulnerable to attack
hasn’t gone unnoticed. As one Chinese newspaper commented in July last year:
“For countries that could never win a war by using tanks and planes, attacking
the US space system may be an irresistible choice.”
The US certainly expects that to happen. Last year a special commission on
the military aspects of space concluded that a conflict in space was “a virtual
certainty”. And during the intelligence community’s annual “world threat”
briefing in February, the heads of both the CIA and the Defense Intelligence
Agency openly voiced their concerns about an attack in space. DIA director
Thomas Wilson warned that several foreign governments were experimenting with
space weapons. He named China and Russia as the biggest threats and predicted
that by 2015, they would be capable of blowing big holes in the US space
programme.
In January the US even held a war game based in space. The scenario was set
in 2018 and involved an enemy state attacking US satellites that were supporting
a military operation on the ground. The results are classified, but the military
made its conclusions clear: without more funding for space defence, the US faces
a Pearl Harbour in orbit.
Independent experts believe there are no weapons in space at the moment,
apart from a gun in the Russian emergency kit on the International Space
Station. There’s also very little on the ground that could do harm in space. But
the technologies to make highly destructive weapons already exist or are in
development.
The simplest way to attack a satellite is with weapons launched from the
ground. That’s the principle behind the “poor man’s ASAT”
(see Diagram). The
idea is to use a small missile to deposit a cloud of sand, ball bearings and
other hard objects in the path of an oncoming satellite. The target’s own
velocity provides the impact energy. It’s unreliable, but it poses a credible
threat. A dozen countries without space capabilities could build such a system,
although none claim to have done so yet.
But there are problems with ground-based weaponry. You can only strike while
the target is in range and it takes time for your missile to climb into orbit.
That gives the satellite time to take evasive action. For this reason, some
strategists want to arm the satellites themselves.
One approach is “parasite satellites”—orbiting limpet bombs that attach
themselves to enemy craft for detonation at a later date. The Chinese say they
can do this already, though the claim is hard to verify. A simpler method is to
disable your enemy with a high-speed projectile. In other words, shoot at it.
This was tried in 1974 when the Soviet Union launched Salyut 3, the first crewed
military reconnaissance outpost in orbit. In anticipation of an attack by the
US, the Soviets mounted a modified machine gun on the satellite so they could
greet any hostile approach with a hail of bullets. The attack never came. Salyut
3 proved to be a white elephant and was quickly decommissioned, although not
without a shot being fired. After the two-man crew had left, the ground crew
fired a few rounds by remote control. It must have been quite a sight.
Shooting projectiles is a standard way of doing combat on Earth, but in space
it’s a little different. For one thing, there’s no atmosphere or gravity, so the
projectile behaves strangely. In low-Earth orbit, most of your bullets would
eventually hit the atmosphere and burn up, though some would settle into a
stable orbit. Some of these orbits would intercept yours, so you’d have be
careful not to shoot yourself down. The rules of engagement are also completely
different. Satellites circle the planet at high speeds, which makes it difficult
to take on an enemy craft in a dog fight.
The simplest way to manoeuvre to within shooting distance is to intercept the
satellite “in plane”. In other words, approach it from behind in a lower and
faster orbit and then boost yourself into its path. From the target’s point of
view, an attack craft would close in from behind and below, and the final few
hundred metres of approach would be almost a straight line.
At this moment a burst of cannon fire would be lethal. The impact would cause
a shock wave in the satellite’s structure, pulverising its electronic equipment,
shattering the glass in viewports and solar panels, and cracking open
pressurised propellant tubes. A hit to a compartment containing oxygen could
start a fire and incinerate the contents. But in the vacuum of space there would
be no billowing Star Wars explosions or shock rings, just an eerie
silence and tumbling, twinkling space confetti.
The victorious craft would then have to avoid the wreckage. Shooting down a
satellite isn’t like shooting down an aeroplane, where the engine or wings are
so badly damaged that it falls out of the sky. Dead satellites continue to
circle the Earth. The same goes for bits of shrapnel.
Debris isn’t just a short-term problem. It can stay in orbit for years.
Soviet ASAT tests in the late 1960s left behind a dozen clouds of metallic
shards which are still a hazard today. The fragments are too small to track and
too numerous to dodge, so all space vehicles have to be armoured against
them.
For this reason, the US is reluctant to start shooting at things in orbit.
After the recent war game, General Ralph Eberhart, commander-in-chief of US
Space Command, told reporters he considered it a last-ditch option. But that’s
not to say space war has been ruled out. In the next couple of decades,
projectiles are likely to be replaced by electromagnetic cannons, lasers and
particle beams—high-tech weaponry capable of inflicting damage without
creating debris.
Electromagnetic cannons are well developed
(New Scientist, 1 July 2000, p 20)
and are probably closest to being deployed in space. They fire
intense bursts of radio waves at their target, jamming or destroying its
electronics. At close range, they could permanently cripple a satellite’s
circuitry. At greater distances their power may only be enough to temporarily
paralyse circuits.
Prototype cannons have already been built and tested. The two main types are
the high-power microwave (HPM) system and the ultra-wide-band (UWB) system. HPM
weapons fire a narrow and powerful beam of high-frequency radiation which can
pierce a satellite’s armour and fry its circuitry. The UWB beam is more of a
scattergun weapon, with a broad beam and wide frequency range designed to knock
out any electronic equipment in the vicinity.
Laser weapons dump large amounts of energy onto the satellite’s surface,
causing violent thermal expansion and setting up shock waves that tear
components from the interior walls. People who’ve seen the damage inflicted by
laser weapons say the effect is like a shotgun blast at point-blank range. So
far lasers have only been used for rangefinding and guidance, but prototype
weapons exist. And if President Bush goes ahead with his plan to revive “Star
Wars”, they could be in space very soon.
For the past 15 years, the US military has been experimenting with lasers at
a test facility in White Sands, New Mexico. This is the home of MIRACL (the
mid-infrared advanced chemical laser), a powerful deuterium fluoride laser built
about 20 years ago for ships, then transferred to White Sands in the mid-1980s
to study its anti-satellite capabilities. In October 1997, MIRACL was test fired
into space. Although not powerful enough to vaporise a satellite, most experts
believe that MIRACL could disable optical equipment and damage solar arrays and
other delicate structures. There are some problems with atmospheric
interference, but putting the laser into orbit would solve those.
Particle-beam weapons inflict damage in a similar way. They emit beams of
particles, perhaps hydrogen or deuterium ions, at near-light speed. Details
remain sketchy, but the principle is essentially the same as in an
ion-propulsion system
(New Scientist, 21 November 1998, p 22).
A working particle beam is believed to have been on board the mysterious Soviet
“battlestar” Polyus-Skif, which was launched in May 1987 but crashed during
take-off. Polyus-Skif also carried a prototype laser for destroying satellites.
In the US, research on particle-beam weapons continues at the High Energy
Research and Technology Facility on Kirtland Air Force Base, New Mexico.
It all sounds depressingly familiar. Humans have only been using space for
the past 50 years, yet we’re already preparing to fight over it. And having
concluded that our present weapons are too messy, we’re building better ones.
There’s even the spectre of nuclear arms in space. For rogue states, the threat
of a nuclear detonation in orbit would be a powerful bargaining chip.
But maybe there’s an upside. Space is a long way off, and a war fought there
by remote control would be all but invisible and harmless to those on the
ground. Way above your head, right now, two nations could be settling their
differences in space. You’d never even need to know.