Early Earth's magnetic field weaker than today, likely led to water loss from atmosphere, bigger auroras.

The U.S. Air Force is gearing up for the first of four planned test flights of a hypersonic aircraft designed to operate for much longer durations and cover far greater distances than previous platforms of its type.

U.S. President Barack Obama will visit Florida April 15 to discuss the impact of his administration's new vision for human spaceflight, the White House announced March 7.

Harmless interstellar hydrogen becomes deadly ionized radiation that would fry the crew and electronics of starships traveling near light speed, according to a physicist.

Buzz Aldrin, 80-year-old veteran of the Apollo 11 moon landing, is gearing up to compete in the new season of TV's Dancing With the Stars.