Never-before-aired NASA footage presents evidence that the Moon is being used as a base.

An epic journey around Mars — built from real satellite and rover data — revealing the red planet as you’ve never seen it before.

Host John Larroquette takes viewers on a nostalgic trip through the 1965-1968 sci-fi comedy series. The disc's rare footage include Guy Williams's screen test, extended clips from the 1965 pilot, bloopers and the original clips CBS network sales presentation. Viewers also get to go behind the scenes of the 1998 big-screen version. To top it off, Billy Mumy (Will), Jonathan Harris (Dr. Smith) and the robot reunite for a special tribute.

Discover the UFO phenomenon like never before, with insights from NASA, CNES, Oxford, compelling firsthand witnesses, and even the possible viewpoint of extraterrestrial visitors.

An IMAX 3D camera chronicles the effort of 7 astronauts aboard the Space Shuttle Atlantis to repair the Hubble Space Telescope.

One of humanity’s greatest achievements, the International Space Station is a $150 billion science laboratory hurtling around Earth at 17,000mph, its thin metal walls shielding astronauts from the most hostile environment humans have ever endured. Microgravity, the vacuum of space, extremes of temperature, micrometeorites - life here is perilous. To mark 25 years of continuous habitation onboard, Space Station We Have a Problem reveals how astronauts are only a technical glitch or software error away from disaster. From malfunctioning spacesuits and docking disasters, critical leaks and even the entire space station backflipping out of control, this is life and death played out in low earth orbit, coupled with the bravery and brilliance that each time, saves the day.

A feature-length documentary about the film Galaxy Quest and its legacy, celebrating its milestone 20th anniversary.

In a studio setting, Stephen Hawking, Arthur C. Clarke and Carl Sagan (who joins them via satellite) discuss the Big Bang theory, God, our existence as well as the possibility of extraterrestrial life.

NASA may have just gotten one step closer to the answering the question: are we alone? The Spitzer Telescope has made a groundbreaking discovery of exoplanets that could be similar to our own. And as Kepler also continues its search, our understanding of the universe continues to be redefined.

A UFO enthusiast interviews Dan Aykroyd on the subject of extraterrestrials visiting Earth.

Nearly forty years after the moon landing the men on the mission reveal what really happened. On how close the mission came to disaster.

Commemorating the space agency's 50th anniversary, follow John Glenn's Mercury mission to orbit the earth, Neil Armstrong's first historic steps on the moon, unprecedented spacewalks to repair the Hubble stories, and more!