Directed energy weapons such as lasers and particle beams, (either ground-based or space-based, having sufficient power to damage satellites or their sensors).

CENTERFORSECURITYPOLICY: Straw in the solar wind

Femtosecond lasers can also be used to interact with other materials and generate particle beams for experiments, says Karl Krushelnick, of the University of Michigan.

ECONOMIST: Ultra-fast lasers

True, they don't shoot enemies out of the sky, but that, at long last, is coming--along with dozens of new applications for lasers as researchers develop new materials and techniques to generate different types of beams that can be more powerful and precise.

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