nvestigations for the study of identical twin astronauts Scott and Mark Kelly and, in doing so, launched human space life science research into a new era. Although NASA's Human Research Program has been researching the effects of spaceflight on the human body for decades, these 10 investigations will provide NASA with broader insight into the subtle effects and changes that may occur in spaceflight as compared to Earth-based environments.

NASA and the National Space Biomedical Research Institute (NSBRI) will jointly manage this ambitious new undertaking.

"We realized this is a unique opportunity to perform a class of novel studies because we had one twin flying aboard the International Space Station and one twin on the ground," says Craig Kundrot, Ph.D. and deputy chief scientist of NASA's Human Research Program.

"We can study two individuals who have the same genetics, but are in different environments for one year.

The investigations, which were picked from a pool of 40 proposals, introduce to space physiology the field of -omics, the integrated study of DNA, RNA, and the entire complement of biomolecules in the human body. Studying human physiology at this fundamental level will provide NASA and the broader spaceflight community with unique information.

This is because these tiny components of the human body tell researchers volumes about an individual's composition and their reaction to stressors like those associated with spaceflight. Investigating the subtle changes - or lack thereof - between the Kelly brothers at this level, after Scott's year in space and Mark's year on Earth, could shed light between the nature vs. nurture aspect of the effects of spaceflight on the human body.

The studies will focus on four areas: human physiology, behavioral health, microbiology/microbiome, and molecular or -omics studies. Human physiological investigations will look at how the spaceflight environment may induce changes in different organs like the heart, muscles or brain within the body. Behavioral health investigations will help characterize the effects spaceflight may have on perception and reasoning, decision making and alertness.

The microbiology/microbiome investigations will explore the brothers' dietary differences and stressors to find out how both affect the organisms in the twins' guts. Lastly, but potentially opening a whole new realm of information about humans exposed to the spaceflight environment are the molecular or -omics investigations.

These studies will look at the way genes in the cells are turned on and off as a result of spaceflight; and how stressors like radiation, confinement and microgravity prompt changes in the proteins and metabolites gathered in biological samples like blood, saliva, urine and stool.

Some of the investigations are brand new, some are already being considered as part of the research plans for the one-year mission set for 2015, and some are already being performed with crews living aboard the space station for six-month durations. These will allow the agency to build upon existing knowledge about long duration spaceflight.

Although the investigations conducted on the Kelly brothers are not expected to provide definitive data about the effects of spaceflight on individuals - because there are only two subjects for data collection - they do serve as a demonstration project for future research initiatives. These investigations may identify changes to pursue in research of larger astronaut populations.

"This is a unique opportunity for the agency," says Kundrot. "The investigations are a pathfinder for the agency with regard to the study of astronaut physiology."

"This pilot project will, for the first time in space, integrate physiology with 21st century -omics techniques currently performed at leading medical schools and hospitals," says Graham Scott, NSBRI chief scientist.

Who knew the next big thing in space life science would be so subtle?