It’s the kind of scene that stays with you.
In the opening acts of Call of Duty: Ghosts, you assume control of an American astronaut who fights desperately to protect a space station from unknown assailants. That station, the Orbital Defense Initiative (ODIN), has the power to bombard the Earth’s surface with giant metal rods launched at hypersonic speed. In the wrong hands, this weapon could threaten the world as sure as any nuclear arsenal.
Of course, you don’t win. As you careen helplessly away from the hijacked ODIN, your suit burning away in the upper atmosphere, you watch as the station activates. Dozens of tungsten poles lance downward, accelerating so quickly that they exceed the terminal velocity of a bullet nearly 100 times over. Within roughly a minute, their first target – New Orleans – has been reduced to rubble. 30 more American cities eventually follow, leaving the United States a battered wasteland and setting the stage for Ghosts‘ story.
While the events of Ghosts are fiction, the ideas and science of ODIN are very real. Alternately referred to as Project Thor, hypervelocity rod bundles, and even “Rods from God,” research into kinetic bombardment has enjoyed a colorful 60-year history among both science fiction writers and U.S. defense planners. While it has yet to move from design to execution, its underlying technologies continue to improve. And should a real-life ODIN ever be built, it would carry truly terrible consequences.
Between fact and fiction
Something brighter than a star showed through, a dazzling pinpoint that developed a tail and vanished, all in a moment.
A long blue-white flame formed, and held for several seconds, while narrow lines of light speared down from one end. Other lights pulsed slowly, like beating hearts.
The sky was alive with strange lights.
…On another night Harry might have taken it for a meteor shower. Tonight…He’d read a hundred versions of the aliens conquering Earth, and they all sounded more spectacular than this flaring and dying of stars and smudges of lights. Any movie would have had sound effects too. But it looked so real.
– Larry Niven & Jerry Pournelle, Footfall
Like many of the weapon ideas that emerged from the dark days of the Cold War, the idea of kinetic bombardment sounds torn from the pages of science fiction. In this case, the concept has danced especially strangely between these worlds. Even the first scientist to seriously study kinetic bombardment in the 1950s, Jerry Pournelle, would eventually leave the research field to become a sci-fi writer.
In the 1950s and 60s, U.S. and Soviet physicists each struggled to turn satellites into viable weapons. While the U.S. concluded early on that space weapons were “clumsy and ineffective ways of doing a job,” both sides kept at it, with the Soviet Union even bringing parts of a system to final test. This competition only stopped with the Outer Space Treaty of 1967, which firmly banned the militarization of space.
This weapon could threaten the world as sure as any nuclear arsenal.
At the same time, the idea of kinetic bombardment crept more and more into popular culture through the 1960s, 70s, and 80s. Among the most notable examples is Robert Heinlein’s The Moon is a Harsh Mistress, in which a weak, poorly armed lunar colonists (“loonies”) declare independence from the powerful empires of Earth. In doing so, they repurpose an interstellar catapult – once used to transport grain – and fill it with steel projectiles instead. When Earth authorities refuse to allow the Moon to secede peacefully, the loonies pepper the Earth’s surface with hypersonic pieces of metal that impact with the force of atomic bombs. After that, the Earth says goodbye to the Moon in a hurry.
The U.S. military found renewed interest in kinetic bombardment in the late 1990s and early 00s. In a widely reported 2003 document, the Air Force made it clear it wanted the “capability to strike ground targets anywhere in the world from space.” That same year, the U.S. quietly changed positions to annul any treaties that limited its “freedom of action” in space. Distracted by wars abroad and troubles at home, however, the nation has had little time to work on killer space stations.
Today, the U.S. military seems to have again lost interest in kinetic bombardment – but popular culture sure hasn’t. Traces of ODIN are everywhere: in Tom Clancy’s EndWar, it’s an American superweapon. It’s Nazis who use it in Iron Sky, while it’s Cobra who use it in G.I. Joe 2. It’s a mod in Kerbal Space Program and a gag in Mass Effect 2. ME2’s gunnery sergeant describes kinetic bombardment best: “[This is why] Sir Isaac Newton is the deadliest son-of-a-bitch in space!”
How ODIN would work – and how it wouldn’t
An important question so far left unresolved is: why? What’s the argument for technologies like kinetic bombardment? How does it work? And, most importantly, is it worth it?
The best argument for ODIN-style weapons is speed. Simply to maintain a stationary orbit over Earth, satellites must travel at roughly 11,300 kilometers per hour – nearly twice the speed of the fastest jet ever produced. In order to actually circle the planet, satellites must go even faster. Launch several such satellites at once and you have a system that can strike anywhere in the world far quicker than a conventional bomb or missile. Furthermore, once rods have been released – plunging downward at hypersonic speeds – they’re essentially impossible to stop or intercept.
The other argument for kinetic bombardment is versatility. The tungsten rods of an ODIN-like device don’t need to carry nuclear warheads or any warhead at all, eliminating the perils of radioactivity and fallout. They can also pierce the earth with force several times that of the strongest “bunker buster” bomb, rendering all possible enemy strongholds useless. U.S. force planners have traditionally seen kinetic bombardment as just one more tool in the arsenal – not as an outright replacement for nuclear weapons.
They’re essentially impossible to stop or intercept.
Basic design of ODIN-style weaponry is remarkably elegant. The giant rods are giant – and rod-shaped – in order to maximize mass while minimizing surface area. They’re made of tungsten because of tungsten’s absolutely insane melting point (3,422 °C), which is high enough to survive atmospheric re-entry. While there are still plenty of engineering challenges – namely, how to make the rods hit the right place at the right time – the whole system is still a lot simpler than your average, nuclear-equipped ballistic missile.
One big, remaining obstacle is money. Putting something in space is stupid expensive – it takes roughly 40 to 50 kilograms of propellant for every kilo launched. When you’re moving literal tons of rare-earth metal, sculpted to be as heavy as possible, those costs add up fast. Launching a single, relatively small rod might cost $30 million dollars. Sending up multiple, large rods spread across multiple satellites would cost many, many dozens of times this.
A world with ODIN: A world nobody wants
The biggest problem with kinetic bombardment, however, is the same problem that’s dogged armchair generals since time began: the enemy also gets a vote.
Satellites and space stations are not exactly safe from harm. In the past decade, the U.S. and China have each experimented with ways of disabling space-borne objects. Satellite jamming is an effective, low-cost strategy that remains very tough to counter. Ground-based lasers – even those with relatively small energy output – can also put the sensitive electronics of a satellite out of commission.
The most direct, effective anti-satellite techniques involve simply blowing these objects out of the sky. In 2010, the U.S. successfully tested an unmanned space plane able to freely maneuver (and likely shoot) in high orbit. Both the U.S. and China have occasionally used missiles to destroy old or failing satellites. One such Chinese test, conducted in 2007, left 40,000 fragments of metal, essentially doubling the manmade debris orbiting the planet. If too many objects were ever destroyed in this same manner, the resulting space junk might keep humans trapped on Earth for good.
So to recap, an ODIN-style device would be an extremely expensive, extremely vulnerable weapons platform whose destruction could well doom humanity forever. In return for all these cons, military planners would get a weapon good at destroying fortified bunkers. On the net, it remains a pretty poor bargain.
The resulting space junk might keep humans trapped on Earth for good.
But what if ODIN were built anyway? What if a group of fabulously wealthy, sci-fi loving engineers (perhaps after playing Ghosts) built and launched their own system of kinetic bombardment?
Put simply, doing so would open all of space to militarization – and push nations across the world to build their own variants. The result would be an arms race not seen since the invention of the atom bomb. The U.S. alone has spent roughly $8 trillion (in 2013 dollars) on the development, testing, and maintenance of nuclear weapons in the years since. It’s difficult to see where this new arms race would end once begun – or how it could do anyone much good.
Kinetic bombardment remains one of the coolest weapons in pop culture, thanks to zany writers and inventive game designers everywhere. Let’s hope it stays fiction.
E.T. Brooking is a defense researcher based in Washington, DC, who still can’t understand where the Tarkin Doctrine went wrong. Follow him on Twitter @etbrooking.