Feb 072007
Authors: Bob Shipton

U.S. astronauts are scheduled today to embark on their third spacewalk in nine days outside the International Space Station. The second of the three runs was completed on Sunday and culminated with Sunita Williams breaking the women’s spacewalking record by accumulating 22 hours and 27 minutes in space.

During the space walk, Williams and space station Commander Michael Lopez-Algeria saw small amounts of toxic ammonia leak from a fluid line. The ammonia could have caused respiratory problems for the entire crew if enough got into the space station.

The dangers associated with NASA endeavors are well documented in history, as well as in cinema. The complications of such missions are immortalized by tragic stories like that of the Space Shuttle Challenger and triumphs like Apollo 13.

But researchers at CSU are breaking new ground and looking at ways to save astronauts from the unseen risks of outer space – risks that are not imminent or life-threatening but could follow the astronauts for the rest of their lives.

“I’m sure when they’re out there wandering around in space, the last thing they’re thinking about is whether they will get cancer in 20 years,” said Dr. Susan Bailey, an assistant professor in the Department of Environmental and Radiological Health Sciences.

In 2003, CSU was given a $9.7 million grant from the National Aeronautics and Space Administration to study the effects of cosmic galactic radiation on astronauts. The scientists have been monitoring mice and cells that have been exposed to the radiation and looking for chromosome rearrangements and other aberrations.

“We’re starting to get results,” Bailey said. “That’s what’s so exciting.”

Dr. Robert Ullrich, the Director of the Cancer Biology Group, a professor in ERHS and principal investigator on the grant, said the type of research going on at CSU could help to better understand the effects of radiation-induced cancers, but that it is more geared toward protecting astronauts in deep space.

“When they colonize the moon and head off toward Mars, the particles out there are so energetic that they deposit huge amounts of energy into cells,” he said.

Ullrich said researchers are trying to find out how well the body can repair the damages the radiation produces, how to identify at-risk individuals and what kind of preventive measures can be taken in order to decrease the risk.

Researchers have been looking at various forms of radiation-induced cancer, but have specifically been looking at acute myelogenous leukemia or AML, a cancer of the blood and bone marrow.

AML is the most common form of acute leukemia affecting adults, with over 11,900 new cases each year, according to the National Marrow Donor Program.

Bailey compared radiation to a double-edged sword because chemotherapy doubles as a possible cause of and treatment for AML.

“Often if women are treated for breast cancer in one breast, there’s the potential to develop radiation-induced cancer in the other,” she said. “The question is how we can identify people with increased risks. Maybe we can figure out why it is that some people get cancer and others don’t.”

Ullrich said that treatments have been changed, but there still are issues with chemotherapy and radiation treatments.

“It’s hard to quantify the risks,” Ullrich said, “because people who already have cancer may be more at risk.”

Researchers are trying to reduce these risks by studying mice rather than humans.

“We just got our first two mice with about half of their bone marrow human,” Ullrich said.

These humanized mice are exposed to heavy ion radiation and some develop a similar form of AML to that of humans.

Bailey said this area of research is expanding because NASA is looking at the possibility of having astronauts in space for longer periods of time, resulting in greater exposure to heavy iron and silicon ions. NASA estimates that a mission to Mars could take up to 900 days to complete.

“It hasn’t been appreciated as much before because there are so many other risks in flight,” Bailey said.

NASA still classifies the launch, orbital maneuvering and atmospheric entry has the highest risks to the flight’s crew.

“I’d be worried about floating in the spacecraft and bumping into the wall,” said junior art education major Tiffany Mehalic. “Or getting disconnected from my cable and floating off into nothingness. Can you face plant on the moon?”

While the focus of the project has been the safety of astronauts in space, Bailey said that research could also help humans who plan on staying beneath the atmosphere.

“If Chernobyl happens again, what do we do with the people that survive?” Bailey asked. “This research allows us to understand the basic mechanisms of radiation induced cancers. The more we know, the better we will be at making assessments of risks.”

The group’s grant is up in a year and a half, but Ullrich thinks they are in good shape to receive funding after they re-submit for a second grant.

“We’re going to have a lot of results, and a lot of things of interest to NASA,” he said. “In the future we’re going to start looking at the next issue, which is these storms (solar flares).”

Staff writer Bob Shipton can be reached at news@collegian.com.

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