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1
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gravity
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Earth
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Gravity is a natural force on Earth that keeps objects on the ground, but its cause is sometimes doubted or attributed to different influences.
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2
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2
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astronaut training
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Earth
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Astronaut training on Earth involves extensive preparation in different environments and emergency protocols.
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1
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3
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space food
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Earth
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Pre-packaged, dehydrated space food on Earth has limited variety and shelf life.
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1
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4
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spacecraft design
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Earth
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Earth's spacecraft design focuses on re-entry capability, thermal protection, and life support systems.
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1
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5
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spacewalks
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Earth
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Spacewalks on Earth are a highly risky endeavor that require meticulous planning and safety protocols.
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1
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