WATERLOO - University of Waterloo scientist Richard Hughson will head a study to explore the effects of weightlessness on Canadian astronaut Robert Thirsk when he joins five colleagues aboard the International Space Station.

Thirsk is a member of Expedition 20/21, which blasts off Wednesday, May 27 on a Russian Soyuz spacecraft from Baikonur, Kazakhstan. He will spend up to six months with the five other crew members on the ISS, with duties that include conducting scientific experiments on behalf of Canadian and international researchers.

They will live and work together as the first crew of six in the world's largest orbiting microgravity scientific laboratory. As a result, they will have more time than any astronaut in the past to conduct scientific experiments in the unique environment of weightlessness.

"Our experiment is the first one to try to look fully at how astronauts' cardiovascular systems cope with microgravity over many months on the International Space Station," said Hughson, an internationally recognized cardiovascular physiologist who is one of the most cited scientists in his field. "The science performed on Expedition 20/21 will provide valuable information to scientists around the world, benefiting both the Canadian and international community."

Hughson, who has a lengthy interest in the challenges of living in outer space, leads the project called Cardiovascular and Cerebrovascular Control on Return from the International Space Station (CCISS), one of several experiments sponsored by the Canadian Space Agency in this the latest expedition.

The ongoing CCISS study investigates the effects of weightlessness on the human body. In examining changes in blood flow, the experiment will require Thirsk to monitor his blood pressure, heart rate and physical activity levels while in orbit.
"The results could be applied to elderly people suffering from dizziness and fainting spells, or those afflicted with heart disease caused by a sedentary lifestyle," said Hughson, a one-time marathon runner who placed third in the 1979 Pan-Am Games. He supervises UW's cardiorespiratory and vascular dynamics laboratory and is a member of the Schlegel-University of Waterloo Research Institute for Aging.

Over the last few years, his research group has been studying astronauts returning from the ISS in an effort to reduce the risk of fainting when they re-enter earth's gravity. They investigate how long periods in space affect the human body and offer approaches that will better protect space travellers in the future.

During Expedition 20/21, Thirsk and his crewmates will collect data for CCISS while they live and work on the ISS. By donning devices and monitors as they perform their activities, they will give researchers information about their blood pressure, heart rate, and other key information about their cardiovascular systems. The data will then be compared with more complex investigations performed on Earth before launch and less than 24-hours after landing.