article_snippet.sent: One problem with space travel is that humans aren’t very good at coping with reduced gravity - humans bones and muscles deteriorate over time.
article_snippet.sent: But one company says one company have an answer - a giant rotating space cylinder that can create artificial gravity.
article_snippet.sent: Their giant cylinder (shown, with the ISS and Space Shuttles illustrated) would rotate four times per minute to create artificial gravity, and would be 1,300ft (400 metres) long, cost £200 billion ($300 billion) and take 30 years to build .
article_snippet.sent: Artificial gravity is created by spinning the station 4.22 times per minute around the station vertical axis, creating downward pressure via the centrifugal force to keep objects - including humans - on the floor.
article_snippet.sent: This would allow spacecraft to dock with the top of the station, which would appear stationary to them. 
article_snippet.sent: Artificial gravity has been considered many times before, most famously in the 'Stanford Torus' design (interior seen here).
article_snippet.sent: A rotating station would allow people to live as if people were walking on Earth, allowing people to stay in space for long periods of time .
article_snippet.sent: The Gemini 11 spacecraft was attached to an Agena target vehicle and spun, with the astronauts reporting a small amount of artificial gravity in the astronauts spacecraft .
article_snippet.sent: In the 1968 film 2001: A Space Odyssey, astronauts are shown running around a spacecraft that spins (shown) while on a mission to deep space, creating artificial gravity for astronauts to operate in .
article_snippet.sent: Previous concepts for spacecraft include this 1969 station that would rotate on its central axis to produce artificial gravity.
article_snippet.sent: The majority of early space station concepts created artificial gravity one way or another in order to simulate a more natural or familiar environment for the health of the astronauts on board .
article_snippet.sent: Nasa's Nautilus-X concept, shown, includes a doughtnut-shaped spinning section in the middle where astronauts can experience artificial gravity.
article_snippet.sent: While a spacecraft could be created with artificial gravity, astronauts will still have to contend with zero-gravity conditions if astronauts ever venture outside into space.
highlights_snippet.sent: Washington, DC company United Space Structures  rotates four times a minute to create artificial gravity - with the 'stem' and 'dome spinning in opposite directions .
  