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Averting Space Doom: Solving the Orbital Junk Problem

Sadly, space lasers and orbital tugboats are unlikely fixes

4 min read
Averting Space Doom: Solving the Orbital Junk Problem
Space-Junk Sifter: Lockheed Martin is building a US $914 million system, called Space Fence, to better track orbital debris.
Photo: Lockheed Martin

We are closer than ever to witnessing the “Kessler syndrome,” a scenario proposed in 1978 by NASA scientist Donald Kessler in which the high density of objects and debris in low Earth orbit creates a cascade of collisions that renders space travel and satellite use impossible for decades. However, how close we really are is a matter of debate.

The United States Space Surveillance Network, operated by the Air Force, estimates there are more than 500,000 pieces of debris larger than 1 centimeter orbiting Earth today, including 21,000 pieces larger than 10 cm that are actively tracked. And that’s ignoring the millions of smaller bits that are also up there. The average speed at which space junk would collide with a satellite is approximately 10 kilometers per second, meaning collisions with debris as small as 0.2 millimeters can still do damage.

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Economics Drives Ray-Gun Resurgence

Laser weapons, cheaper by the shot, should work well against drones and cruise missiles

4 min read
In an artist’s rendering, a truck is shown with five sets of wheels—two sets for the cab, the rest for the trailer—and a box on the top of the trailer, from which a red ray is projected on an angle, upward, ending in the silhouette of an airplane, which is being destroyed

Lockheed Martin's laser packs up to 300 kilowatts—enough to fry a drone or a plane.

Lockheed Martin

The technical challenge of missile defense has been compared with that of hitting a bullet with a bullet. Then there is the still tougher economic challenge of using an expensive interceptor to kill a cheaper target—like hitting a lead bullet with a golden one.

Maybe trouble and money could be saved by shooting down such targets with a laser. Once the system was designed, built, and paid for, the cost per shot would be low. Such considerations led planners at the Pentagon to seek a solution from Lockheed Martin, which has just delivered a 300-kilowatt laser to the U.S. Army. The new weapon combines the output of a large bundle of fiber lasers of varying frequencies to form a single beam of white light. This laser has been undergoing tests in the lab, and it should see its first field trials sometime in 2023. General Atomics, a military contractor in San Diego, is also developing a laser of this power for the Army based on what’s known as the distributed-gain design, which has a single aperture.

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