for National Geographic News
The space shuttle Discovery successfully finished its latest voyage today, touching down at Cape Canaveral, Florida, at 9:14 a.m. local time.
But science experiments started during the 13-day mission will continue.
Throughout their nearly two weeks in space, the crew kept diaries of their sleeping habits and filled containers with various bodily fluids.
The tasks were part of experiments designed to help better prepare astronauts to stay healthy during long-distance space flights to the moon and Mars.
"We want them to be in the best shape possible," said Daniel Feeback, a Discovery mission scientist and director of the Muscle Research Laboratory at the NASA Johnson Space Center in Houston, Texas.
Feeback's lab is part of the center's Human Adaptations and Countermeasures Division, which studies the effects of spaceflight on human health.
Specifically, researchers hope to learn more about the effects of radiation exposure on the human body; how spaceflight affects the immune system; and whether spaceflight can reawaken viruses, such as herpes, that can lie dormant.
In one experiment during the July Discovery mission, astronauts wore wristwatches that monitored their round-the-clock activity and patterns of light-exposure.
The data, combined with daily journal entries on sleep quality, should help scientists design drugs and sleeping arrangements that keep astronauts well-rested and alert.
SOURCES AND RELATED WEB SITES