Every year, companies and space agencies launch hundreds of rockets into space—and that number is set to grow dramatically with ambitious missions to the moon, Mars and beyond. But these dreams hinge ...

Bionic bladeless propellers, inspired by the effortless movement of jellyfish, are transforming aquatic propulsion. Traditional propellers are noisy, inefficient, and hazardous to marine life, but ...

WASHINGTON — A DARPA official said the agency canceled a space nuclear propulsion project it was jointly developing with NASA in part because the effort was overtaken by advances in more conventional ...