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Interplanetary GPS Comes a Step Closer

A ground simulator is constructed and a space-station test is planned

4 min read
Interplanetary GPS Comes a Step Closer
Illustration: NASA

05NWInterplanetaryGPSmasterGalactic GPS: Interplanetary navigation systems are already being tested for future flights to other planets and beyond. The Juno spacecraft (above) will have to get to Jupiter the old fashioned way.Photo-Illustration: NASA

Humans have long used the light of stars to guide them toward their destinations. But in the age of extraterrestrial exploration, it could be the pulses of X-rays from dead stars that guide us through deep space. A NASA team recently built a critical system that will finally let them test such an “interplanetary GPS.” A version of the system could be installed on the International Space Station (ISS) as early as 2017.

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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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