Top 10: Space Weapons

Large nations are now racing for space age weapons. These are some of the most advanced and sophisticated weapons built to take the arms race to the next level.

No. 10: anti-satellite Missile:

The ability to destroy man-made satellites in orbit around Earth has already been demonstrated by China, who used an anti-satellite (ASAT) device against one of their own weather satellites. The US likewise shot down a crippled spy satellite in 2008 with a sea-based missile. India has said they wish to develop similar capabilities. The problem: Huge swarms of space debris generated by blowing up objects remain in orbit, and threaten manned spacecraft.

No. 9: Warm Jets:

Does a device that uses electromagnets to shoot a stream of molten metal at incredible speed toward enemy targets sound far-fetched? The Defense Advanced Research Projects Agency (DARPA) is already working on one, with the appropriately aggressive-sounding name of "MAHEM" (Magneto Hydrodynamic Explosive Munition). Pictured is Earthlight, an Arthur C. Clarke novel that presaged exactly this device.

No. 8: A Deadly Ray:

Directed-energy weapons utilize lasers, high-powered microwaves, and particle beams. Projects in development by the US have names like Airborne Laser, the Active Denial System, and the Tactical High Energy Laser (THEL). However, before these weapons can "stun" or "kill" like a Star Trek phaser, engineers need to do much work to weaponize the various forms of energy under consideration.

No. 7: Star Stronghold:

Weapons in space need not be so exotic. Take the former Soviet Union's Almaz Space Station of the 1960s and '70s. The military space station reportedly carried a cannon to destroy satellites or incoming spacecraft. It was even reportedly tested (while no one was aboard the spacecraft) to demonstrate its feasibility. Other space-based conventional weapons could include more exotic packages of destruction, such as radio-frequency or high-power-microwave munitions.

No. 6: Space Parasite:

Home-grown microsatellite and nanosatellite technologies are being proliferated by a number of nations, hinting at some military uses. In one U.S, Department of Defense report, military officials took at face value a Hong Kong newspaper account in January 2001 that claimed China had developed and tested an ASAT system using a "parasitic microsatellite." Apparently this device could have been a small satellite designed to attach itself to other satellites to destroy or damage them. This neat but unsubstantiated assertion quietly vanished from further DoD reports.

No. 5: The Overload:

High-altitude weapons using electromagnetic energy may destroy and disrupt electronic and electrical devices, causing a burst of electromagnetic radiation (electromagnetic pulse, or EMP) to produce current and voltage surges. These bursts are commonly associated with nuclear explosions, but scientists have produced non-nuclear EMP's. The construction of small "e-bombs" poses a significant terrorist threat against airplanes.

No. 4: Moonraker:

Deploying nuclear bombs in outer space seems like a natural goal of the military. Indeed, in the 1950's the US Air Force planned to detonate a nuclear bomb on the moon. This effort, dubbed Project A 119, included a young Carl Sagan on its team. At the time, an intercontinental ballistic missile (ICBM) carrying a nuclear warhead possessed the capability to reach the moon. Fortunately, the man in the moon was spared.

No. 3: Rods from Gods:

Scheduled for a test flight on April 20, 2010, the reusable robotic X-37B Orbital Test Vehicle (OTV) is a small space shuttle-like craft developed by the US Air Force. If such a reusable space plane becomes feasible, it will offer unheard-of capabilities for launch on-demand, surprise, and flexibility. If those benefits aren't enough, the space plane may be outfitted with a weapon to drop tungsten rods on Earth targets from outer space, the so-called "Rods from Gods."

No. 2: You Can't Hide:

In the USAF's Manned Orbital Laboratory (MOL) program of 1965, two astronauts would launch atop a Titan 3 rocket in a spacecraft similar to NASA's Gemini capsules, then conduct reconnaissance missions from orbit using ultra high-resolution telescopes. The project was scuttled in 1969, and unmanned spy satellites proved a better option later.

No. 1: Space Catapult:

Could an orbiting asteroid be manipulated to smash down on an enemy target on Earth? It's possible, but doesn't seem like an efficient way of doing battle, according to a RAND think-tank report. More effort would be required to achieve such a result than was employed to develop the first A-bomb during the Manhattan Project in WWII, they say.