Mixed Up In Space

The Weightless Environment Brings Special Challenges To Astronauts. Mark Lee Tetherless and FreeImagine waking up in space. Groggy from sleep, you wonder ... which way is up? And where are my arms and legs? Throw in a little motion sickness, and you'll get an idea of what it can feel like to be in space. Consider, for example, 'up' and 'down.' On Earth we always know which way is up because gravity tells us. Sensors in our inner ears can feel the pull of gravity and tell our brain which way is up. In space, however, there is no pull of gravity and the world can suddenly seem topsy-turvy.

Our balance isn't the only thing affected by the absence of weight. The nerves in our body's joints and muscles normally tell us where our arms and legs are without having to look. But without the pull of gravity, we can lose that awareness, too.

These sorts of mismatches between what the eyes see and what the body feels can trigger 'space sickness.' Figuring out how to prevent space sickness, and how to treat it when it happens, is a high priority for NASA. For that reason, in 1997, NASA helped establish the National Space Biomedical Research Institute (NSBRI). There researchers study how humans adapt to weightlessness and work to develop 'countermeasures' against space sickness. Much of the NSBRI's research is conducted on Earth and can directly benefit millions of people who never leave our planet. For example, an estimated two million American adults suffer chronic problems with dizziness or balance. Figuring out why we're mixed up in space can have some down-to-Earth benefits!

About the Author

NASA Marshall Space Flight Center

NASA Marshall Space Flight CenterThe George C. Marshall Space Flight Center, located in Huntsville, Alabama, is the U.S. government's civilian rocketry and spacecraft propulsion research center. As the largest NASA center, MSFC's first mission was developing the Saturn launch vehicles for the Apollo program.