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Space Shuttle Launch Called Off

An important sensor in the fuel tank failed

2 min read

Cape Canaveral, Fla., 13 July 2005--Today's planned launch of the space shuttle Discovery was scrubbed with just two and a half hours to go. The crew had already boarded and was being strapped into their chairs by NASA's close out crew when Kennedy Space Center's firing room, which controls launches, detected a failure in one of four sensors in the massive orange external tank that supplies propellants to the space shuttles main engines.

These sensors warn when the fuel level in the tank is running low during flight and allow the shuttle's engines to be shut down before the fuel is completely exhausted. If the engine were to continue running on empty there is a strong risk of what NASA calls an "uncontained failure," which in practice means anything from an individual engine meltdown to an explosion.

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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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