Gravity is like milk. It does a body good. The same force that keeps you grounded on Earth makes muscles strong and bones sturdy. So what happens to astronauts who spend a lot of time — sometimes weeks or months — in nearly weightless environments? For 30 years, NASA has been trying to find out. Because any matter creates a gravitational field, weightlessness is virtually impossible to obtain. However as astronauts move away from Earth in space, gravity becomes weaker and astronauts can feel almost “weightless.”
