(NaturalNews) In a $1.5 million project intended to examine the effects of space travel on the human body, NASA will launch one astronaut into space for a year while his identical twin remains back on Earth, so scientists can analyze any differences between the two twins when the first brother returns.
The 50-year-old twins, Mark and Scott Kelly, are the only identical twins to ever have both flown into space. They both are retired U.S. Navy captains and told their grandmother at age eight that they both wanted to go into space some day.
Mark Kelly, the husband of former Congresswoman Gabrielle Giffords, has flown into space four times as a space shuttle pilot and commander, most recently in 2011. He will remain on Earth while his brother Scott spends 12 months on the International Space Station. By the time he returns, Scott Kelly will have spent a total of 540 days in space, including a prior six-month trip to the space station. He said that he expects the upcoming trip to be more pleasant than the last, as the station's email, telephone, entertainment and exercise facilities have significantly improved, as has its air quality.
The twins themselves were the ones to suggest the possibility of the study.
"They have a very long-term vision," said Dr. Andrew Feinberg, of Johns Hopkins University School of Medicine. "It's kind of amazing."
Feinberg was one of 10 scientists to receive funding from NASA to perform studies on the twins. Researchers will take various measurements from the brothers before Scott Kelly's journey, recording everything from genetics and biochemistry to cognition, vision, digestion and immune function. Feinberg's research, for example, will focus on epigenetics, environmentally induced changes in gene expression.
Because the brothers are genetically identical, any radical changes between them over the course of a year are likely to be due to Scott Kelly's time in space -- whether due to radiation, lack of gravity, limited diet, psychological stress or some other factor.
"This is a unique opportunity. We can study two individuals who have the same genetics but are in different environments for one year," said Craig Kundrot, deputy chief scientist of NASA's human research program.
Study may uncover secret of aging
One of the studies approved and funded by NASA will be conducted by Colorado State University researcher Susan Bailey. Bailey studies the chromosomal structures known as telomeres -- small "caps" of DNA at the end of each chromosome that naturally decay over time. Telomere decay is believed to be linked to programmed cell death and many of the effects of aging. For example, some studies have shown that people who exercise regularly have longer telomeres than people who are more sedentary.
"Taking care of your telomeres is an important thing to do, and having a healthy lifestyle is a big part of that," Bailey said. "Can you imagine a more stressful thing than strapping yourself in a rocket or living in space for a year?"
Bailey is especially interested in the effects of radiation exposure, as prior studies have shown that as little as five days of radiation exposure can produce severe telomere deterioration.
Bailey also plans to study the Kelly brothers' levels of telomerase, an enzyme known to play a role in extending telomere life. Although having such an enzyme be more active might seem like a good thing, higher telomerase levels seem to stimulate infinite replication without cell death -- in other words, cancer. This may be why telomerase typically becomes inactive in the body shortly after birth.
"The fact that telomerase gets turned off after birth is truly a tumor suppressor," Bailey said.