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How Weightlessness Works


What can be done to help you deal with the microgravity environment? With respect to non-living things, every object in the shuttle or space station must be stowed in lockers, strapped down or attached to the wall with Velcro.

For example, when you eat a meal in microgravity, you must be held to the shuttle with footholds, and your food tray is attached to you with a strap. Your food tends to be in forms that are sticky or pasty, like rice or peanut butter, so that it does not float away. If you are at a work station, you use straps and footholds to restrain yourself. Portable equipment, such as a laptop computer, is strapped to either you (as shown above), an equipment rack or the wall of the spacecraft.

As for all of these changes that occur in your body during your stay aboard the International Space Station, what can you do to remain healthy, especially upon your return to Earth? Remember that we have to deal mainly with three changes:

  • Fluid loss
  • Loss of muscle tissue
  • Loss of bone mass

Fluid Loss

One countermeasure to deal with fluid loss is a device called lower body negative pressure (LBNP), which applies a vacuum-cleaner-like suction below your waist to keep fluids down in your legs. This device might be attached to an exercise device, such as a treadmill. You might spend 30 minutes per day in the LBNP to keep your circulatory system in near-Earth condition.

Test of LBNP device
Test of LBNP device
Photo courtesy NASA

Also, just prior to your return to Earth, you can drink large volumes of water or electrolyte solutions to help replace the fluids you've lost. This can prevent you from fainting when you stand up and step out of the shuttle.

Deterioration of Muscles and Bones

NASA and the Russian Space Agency have found that the best way to minimize loss of muscle and bone mass in space is to exercise frequently. This trains your muscles, prevents them from deteriorating and places stress on your bones to produce a sensation similar to weight. You exercise as much as two hours every day on various machines (treadmill, rowing machine, bicycle). You have to be restrained during your exercise, usually by tension-producing straps, such as bungee cords, that hold you to the machine.

Much more research needs to be done to develop countermeasures to the body's changes in microgravity. This research must be conducted both on the ground and in outer space -- aboard the International Space Station -- using both humans and animals. The results of such research will help to improve the health of astronauts and pave the way for long-term space exploration, such as a trip to Mars.

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