Earth is the only home we've ever known, and it's treated us well so far. But whether it’s climate change, an apocalyptic asteroid, or some horrifying disaster we don’t even know about yet, the Earth won't live forever.
In 2014, the International Space Station had to move three times to avoid lethal chunks of space debris and there is an increasing problem of satellites mysteriously breaking down. With first-hand accounts from astronauts and experts, Horizon reveals the scale of the problem of space junk. Our planet is surrounded by hundreds of millions of pieces of junk moving at 17,000 miles per hour. Now the US government is investing a billion dollars to track them, and companies around the world are developing ways to clear up their mess - from robot arms to nets and harpoons. Horizon investigates the science behind the hit film Gravity and discovers the reality is far more worrying than the Hollywood fiction.
After visiting the Moon, humanity seeks to explore deep space and learn to live beyond the Earth. This requires extensive experimentation, and the building of NASA's first space station - Skylab. Thus begins a new stage in space exploration, heralding the replacement of rivalry with partnership; The International Space Station unites over a dozen nations - with Japanese, Canadian and European astronauts aiming to complete it by 2010. Meanwhile NASA's greatest asset - the Hubble Space Telescope - reveals what is waiting for us deep in space, having begun its life as NASA's most famous mistake.