Flexi Says: NASA has conducted studies on long term spaceflight with astronauts who have lived on board the International Space Station (ISS) for more than 200 days. Major effects of long term spaceflight include loss of bone and muscle tissue from the body adapting to a low gravity environment as well as psychological stress due to isolation and feeling confined in a cramped environment away from Earth. Astronauts also experiences changes in their microbiomes--the communities of helpful bacteria that live in the digestive tract, nose, and skin. Disruptions to the microbiome have caused problems with digestion, rashes, and immunity. Astronauts are also exposed to higher levels of radiation in space, however recent studies have not detected any significant increase in cancer rates. Space quarters and vehicles have to be built with radiation shielding to minimize this risk.