We're all concerned with our health, but those who travel into space have more to be concerned with. Weightless environments change how everything works, including the heart. What happens to heart strength and size when you live without gravity for weeks or months at a time?
These are the questions that the NASA Integrated Cardiology Project set out to answer. It's been going on for some time now, and has ended recently. One thing that scientists have learned is that the heart actually gets smaller when in a weightless environment and that certainly has implications for those coming home after a long voyage.
The most interesting possible outcome of this research is the potential to explore what might happen to earthbound people who are bed-ridden or unable to live active lifestyles. If scientists are able to come up with strategies for keeping the astronauts healthy, those same strategies may be applicable to us back on earth.
Here's a fascinating video featuring NASA's Michael Bungo, co-investigator for the Integrated Cardiovascular experiment.