A byproduct of aging nuclear weapons stockpiles could help power spacecraft on missions lasting decades. Americium-241, an isotope that can be separated from aged plutonium, is being studied as a ...

One would think that this excellent question would be easy to answer: A bucket full of “deep space” would contain essentially nothing — and, well, there you are! Outer space is, after all, the closest ...

NASA's ambitious mission to return astronauts to the moon for the first time this century is on track to launch no later than April 2026, but it just might fly sooner if all goes well. Final tests of ...