Houston Chronicle (Internet / Print) 01/31/06http://www.chron.com/disp/story.mpl/space/3624056.html "President Bush has made it clear we are heading to Mars. There's much we still don't know about the effects of the weightless environment on the human body. We depend on volunteers to help us learn more. They're part of the mission, too," said Janice Meck, bed-rest project scientist at the space center. The studies are conducted at the University of Texas Medical Branch in Galveston, under the constant supervision of doctors and other health-care workers. Subjects remain in beds tipped downward at a six-degree angle. A prolonged stay in space leads to cardiovascular deconditioning, muscle atrophy, decreased bone strength, and shifts in fluid and electrolyte balances — all conditions duplicated in the bed rest study.