Space travel is all well and good, but returning home to Earth provides another set of problems. Get ready to be quizzed about Yuri Gagarin's crash landing, cutting-edge shuttlecraft, and orbital space flight. Your quiz starts now...

One of America's greatest achievements is also one of its most controversial. Now a team of experts investigate if there was a conspiracy to fake the moon landing, uncovering a secret report on hundreds of Nazis' involved in the Apollo space program.

Some believe the fire on Apollo 1 that killed three astronauts was a top-secret cover-up, and a team of experts investigate if this disaster was a tragic accident or part of a conspiracy to fake the moon landing.

Apollo 11's lunar module nearly killed Neil Armstrong during training. Some believe this close-call could explain a conspiracy to fake the moon landing. Experts investigate if dangers that the Apollo 11 crew faced were motive for a cover-up.

Strange flying objects have been caught on NASA’s cameras and astronauts have reported seeing UFOs. Some can be identified; others remain a mystery. We’ll reveal NASA footage and interview the astronauts and scientists.

Astronaut Leroy Chao’s spacewalk is interrupted by bright lights flying past. A flying saucer photographed from the Apollo capsule, dark shapes caught on camera shadowing the shuttle. The ideas are science fiction, but the incidents are science fact.

The Viking Lander may have found life on Mars, so why don’t we know about it? What is the most destructive force in the universe? How could a starship be seen in the Aurora Borealis? And what are NASA’s mysterious Moon Pigeons?

A chunk of the sun appears to have vanished. An ominous dark craft beneath the Space Shuttle Endeavour. Hubble spots thousands of unidentified objects traveling faster than light. Are we being watched?

A distant planet shows evidence of an Earth-like atmosphere, while a mysterious light suggests an atmosphere on the Moon. Have we found evidence of a crashed alien ship in the asteroid belt? Why are there "blueberries" on Mars?

Could spaceships be powered by atomic bombs? Can artificial rings encircle an entire star? why was Neil Armstrong’s transmission feed cut off when he spotted strange lights on the Moon? And how can lightning talk to itself?

What could make a NASA astronaut report seeing a flying saucer in the skies above a US Air Force test range? How have the swirling gases of Saturn formed a perfect Hexagon that has hovered above the planet’s pole for 30 years?

A UFO crashes in Pennsylvania. Was it a secret Soviet satellite or something far more dangerous? On Mercury, NASA finds the impossible: frozen water. A strange object causes a skyscraper-sized shadow on the surface of Mars's largest moon. What is it?

Was the Moon landing faked? Images of Mercury reveal massive spider-like formations on its surface. Is it a geological formation or something ominous? A classified Space Shuttle mission ends in near-disaster. What was its mission?

Are burning lights above Nevada and Utah signs of a secret space weapons project? What are the odd trails on the lunar surface near the Apollo landing sites? Does a strange space object spell disaster for the Space Shuttle crew?

How could an astronaut on a spacewalk begin to drown? Have NASA scientists discovered an asteroid that was converted into a spacecraft? What are the strange objects spotted when NASA sends a secret payload into space?