NASA’s Kelly Twins Study
How Space Affects Human Physiology
Life Sciences Lead, Lead Mission Scientist for the Twins Study
Office of the Chief Scientist
About the Lecture
The full array of 21st century “omics”-based research methods should be intelligently employed to reduce the health and performance risks that astronauts will be exposed to during exploration missions beyond Low Earth Orbit. In March of 2015, US Astronaut Scott Kelly launched to the International Space Station for a one year mission while his twin brother, Mark Kelly, a retired US Astronaut, remained on the ground. This situation presented an extremely rare flight opportunity to perform an integrated omics-based demonstration pilot study involving identical twin astronauts. A group of 10 principal investigators was competitively selected, funded, and teamed together to form the Twins Study. A very broad range of biological functions are being examined at the same time in both twins, including the genome, epigenome, transcriptome, proteome, metabolome, gut microbiome, immunological response to vaccinations, indicators of atherosclerosis, physiological fluid shifts, and cognition. The design of the Twins Study and an overview of initial results will be presented in this lecture, and the technological and ethical issues raised by for such spaceflight studies will be discussed. An anticipated outcome of the Twins Study is that it will place NASA on a trajectory of using omics-based information to develop precision countermeasures for individual astronauts to address adverse effects of spaceflight and maintain astronaut health on long duration exploration missions.
About the Speaker
Craig Kundrot is the Life Sciences Lead in the Office of the Chief Scientist at NASA where he coordinates life science research in astrobiology, human research, planetary protection and space biology within NASA and with other organizations. Before joining NASA Craig was an x-crystallographer and worked on protein and RNA structure-function relationships at Yale, the Medical Research Council Laboratory for Molecular Biology in Cambridge, England, and the University of Colorado. He continued this work at NASA before assuming science management positions for biotechnology and materials science. He then served as the Deputy Chief Scientist for NASA’s Human Research Program (HRP) and as the first Mission Scientist for the HRP’s Twins Study. He also served as Chair of the Institutional Review Board at NASA Johnson Space Center helping formulate NASA’s genetic research policy for astronauts. During his NASA Career Craig has been awarded three Center Director commendations and six Special Service Awards. He earned a BA in Integrated Science with a minor in Biochemistry at Northwestern University a MPhil and PhD in Molecular Biophysics and Biochemistry at Yale.
President Larry Millstein called the 2365th meeting of the Society to order at 8:08 p.m. He announced the order of business and welcomed new members. The minutes of the previous meeting were read and approved. President Millstein presented a summary of the 27th meeting of the Society, held in May 1872. President Millstein then introduced the speaker for the evening, Dr. Craig Kundrot, Life Sciences Lead and Lead Mission Scientist for the NASA Twins Study in the Office of the Chief Scientist at NASA. His lecture was titled “NASA's Kelly Twins Study: Characterizing the Effects of Space Flight from ‘Omics’ to Cognition”.
Dr. Kundrot began by explaining that Mars is the “horizon goal” for NASA, with a manned mission planned for the 2030s. Preparations are already underway for the journey, and the Kelly Twins Study is a way to learn about how spaceflight affects what NASA refers to as “the human system”.
The leading plan for a manned mission to Mars is a “conjunction-class” or “long stay” mission, consisting of a six month transit to Mars, an eighteen month stay, and a six month transit back, to take advantage of favorable orbital alignment of the Earth and Mars. The risks such an extended mission would expose the crew to fall into three main categories: abnormal gravity, radiation exposure, and psychological effects.
In microgravity and zero-G environments, “sedimentation” does not occur, so objects and substances do not fall as they normally would, including inside the body. Hydrostatic pressure is absent, which changes blood flow and affects fluid shifts. Convection also ceases, so heat dissipation becomes problematic.
Radiation from solar flares is relatively simple to shield against. The real threat is galactic cosmic rays, which are the nuclei of atoms, from simple hydrogen up to iron, which are traveling at a fraction of the speed of light. Because GCRs can be so high energy, they are difficult to effectively shield from. GCR exposure for astronauts is approximately equivalent to a chest X-ray every ten days.
Psychological stressors for astronauts include isolated, confined conditions and social and environmental monotony. They will not have circadian cues, without which individual sleep/wake cycles can diverge dramatically. The international crew will also face interpersonal, cultural, and organizational differences.
Preliminary studies on the physiology of space flight have shown predictable changes across multiple body systems, some of which equilibrate with time and others, such as bone loss and radiation exposure, which show an incremental accumulation. To send a mission to Mars, scientists need better understand the extent of these changes and the long-term effects on astronauts.
In 2012, as astronaut Scott Kelly was preparing for his year-long mission to the International Space Station, he suggested the possibility of a study to take advantage of his identical twin, astronaut Mark Kelly, who would stay on Earth. NASA ultimately accepted proposals for a suite of studies that would leverage the plunging cost of genome sequencing to examine in minute detail the effect of space travel from the genome up to the level of the entire body. This “-omics” based analysis would provide insight into effects from cellular aging and regulation to organ systems such as immune function, the gut microbiome, and cognition.
The major data collection for these studies is complete and those samples will be processed by the end of this year, with analysis to begin in January and a combined paper planned for 2017.
Dr. Kundrot noted that we have never before had such insight into the biological factors affecting the health of an individual, making this study a landmark in bioethics, as well. For the study, NASA developed its first Genetic Research Policy to address questions of privacy, publicity, medical usage, and the relationship between researcher and subjects.
Dr. Kundrot concluded by noting that Mars is the horizon destination for human space exploration, and the Kelly Twins Study will help us to better understand the way spaceflight affects the many -omics of the human system. It also provides a preview of the new social and ethical questions that emerging omics-based analyses will raise on Earth.
After the conclusion of the talk, President Millstein invited questions from the audience.
One questioner asked how samples from the astronaut’s “microbiome” were preserved without disrupting the organisms to be studied. Dr. Kundrot explained that swabs of the sample are placed in an a -80 degree freezer, and that “shotgun sequencing” will be used to analyze all DNA in the sample directly, without requiring live microbes to culture.
Another questioner asked why NASA is pursuing human space flight. Dr. Kundrot explained that NASA is doing a great deal of science with robots, and that Mars is likely to be a combined mission with both robots and humans. For example, in areas with particular potential for evidence of life, robots may be used to avoid contaminating the site. Nonetheless, he noted, it is part of the human spirit to explore, and it would not be the same if we only ever sent robots.
After the question and answer period, President Millstein thanked the speaker, made the usual housekeeping announcements, and invited guests to join the Society. At 10:04 p.m., President Millstein adjourned the 2365th meeting of the Society to the social hour.
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