Countdowns

The Mercury program launched the first Americans into space, four on suborbital flights, and two who orbited the Earth.

Here's where to go to get your space shuttle fix in museums across the United States.

Earth has been sending probes to Mars for decades, and some missions are especially awe-inspiring.

Here are some of the more prominent Mars movies over the decades, to encourage you to keep exploring.

In honor of the 40th anniversary of "Star Wars: A New Hope," here are 40 surprising facts about the movie that started it all.

Humans have sent many missions, both manned and robotic, beyond our planet to explore our neighboring celestial bodies.

Apollo 13 was NASA's third moon-landing mission, but the astronauts never made it to the lunar surface. Here are the events that transpired.