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Here's Dr. Textbook with an exciting look into the history of living in space.

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Hello.

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Well, today we're going to learn about one of man's greatest challenges, living in space.

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For centuries, people have adjusted to different living conditions, but none so drastic as

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going from the surface of our planet into outer space.

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Leaving the pull of Earth's gravitational force requires training and discipline.

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NASA astronauts use sophisticated simulators and machines to prepare themselves to leave Earth's gravity.

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You experience the same feeling while riding on a roller coaster or even while spinning on a merry-go-round.

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Once you've entered space, however, everything changes.

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You've left Earth's gravitational force behind you, and you've now entered the microgravity zone.

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In a microgravity environment, you must be able to work right side up or upside down.

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Doing this on Earth can be slightly uncomfortable, but in space there is no up or down.

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It feels the same no matter which way you hang.

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Also in microgravity, simple tasks like eating are very challenging.

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In the early days of spaceflight, astronauts relied on orange-powdered drink mix and freeze-dried food.

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Now they enjoy a variety of full-course meals.

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Of course, life in space does have its benefits.

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On Earth, these weights are difficult to lift, but if I let go of them in space, they simply stay put.

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Not a very good idea!