After Extensive Data Gathering and Analysis—Plus a Worldwide Media Frenzy—NASA’s Famed Twins Study has Begun to Yield Results


It has been called the most comprehensive analysis of individual human beings ever conducted in scientific history. In March 2015, astronaut Scott Kelly rode a Soyuz spacecraft to the International Space Station and proceeded to spend 340 days in orbit as part of an in-depth study of the long-term effects of space travel on the human body. As rare and valuable as that effort was—representing the longest-ever space mission for a NASA astronaut—it was all the more remarkable thanks to a tantalizing offer from Kelly’s identical twin brother: Mark Kelly, himself a retired astronaut. Since Mark was staying on terra firma, he volunteered to serve as an experimental control, allowing scientists to compare two genetically identical men—one on Earth, the other in zero gravity some 220 miles above it, traveling at almost five miles per second.


The cover of Science featuring the Twins Study.

During Scott’s time on the space station (as well as six months before and after his mission), the brothers underwent physical and cognitive testing and contributed numerous blood, urine, saliva and fecal samples for analysis. Dubbed the NASA Twins Study, the effort comprised 10 interconnected research projects—on such topics as cognition, cardiovascular health, genomic changes, immune response, and the composition of gut, skin and oral bacteria—funded by a total of $1.5 million in agency grants and involving dozens of investigators around the country and abroad.

One of those projects, which focused on how Scott’s environment affected how his genes were expressed and regulated, was led by Weill Cornell Medicine’s Dr. Chris Mason—and along with the nine others, it would make headlines around the world. In April, the Twins Study landed on the cover of the journal Science, which featured a 20-page article summing up the results—the first publication of what’s expected to be many, as researchers continue to parse a mother lode of data. “Overall, the Twins Study is a tour de force about how the body’s adaptability extends to outer space,” says Dr. Mason, the WorldQuant Foundation Research Scholar in physiology and biophysics and an associate professor of neuroscience, of physiology and biophysics, and of computational genomics in computational biomedicine. “The vast majority of changes we saw returned to normal—but about 8 or 9% remained. So it also shows that the body was still to some degree adapting to terrestrial life, even six months after Scott Kelly returned to Earth.”

Among the Mason Lab’s findings were that thousands of genes became active in Scott while remaining dormant in Mark—an effect that became more marked the longer Scott stayed in space. Those genes included ones that play a role in repairing damaged DNA—which may reflect the fact that while in space, Scott was exposed to nearly 50 times as much radiation as his brother was on Earth. Also active were genes related to inflammation, which could be due to the inherent stresses of space travel on the human body; these include the effects of being in zero gravity, such as fluid shifts and bone loss. For Dr. Francine Garrett-Bakelman, who was the first author on the Science paper, the findings made sense. “I’m a physician-scientist, and as a physician, I thought, ‘Yes, an astronaut is under significant stress,’” says Dr. Garrett-Bakelman, who completed her research and medical postgraduate training at Weill Cornell Medicine (where she was an instructor and an assistant attending physician at NewYork-Presbyterian/Weill Cornell Medical Center while working in Dr. Mason’s lab and that of Dr. Ari Melnick, the Gebroe Family Professor of Hematology/Oncology).  She is now an assistant professor of medicine and of biochemistry and molecular genetics at the University of Virginia School of Medicine, as well as an adjunct assistant professor of medicine at Weill Cornell Medicine. “He gets launched into space, spends a year in a foreign environment, then comes down to Earth subjected to a tremendous amount of g-forces. It tells us that the human body is resilient and responding normally to a stressful situation.”


MIRROR IMAGES: Twins Mark (left) and Scott Kelly. Opposite page: Scott on a spacewalk—his third—in December 2015. Credit: Robert Markowitz/ NASA / Johnson Space Center

As Dr. Mason notes, a particularly striking finding was the extent to which Scott’s immune system was on high alert once he went to space: every type of immune cell the researchers measured was active at levels that are practically unheard of. And in fact, Dr. Mason says, the response was even more dramatic when Scott came home. “In his memoir, he says that when he landed back on Earth he didn’t feel well—and we could see why very clearly, in his blood work and gene expression data,” says Dr. Mason, who is also a cofounder, equity stakeholder and consultant for Onegevity Health, a company that provides a comprehensive molecular portrait and customized recommendations for an individual’s health based on integrated analysis of longitudinal blood, genetics and microbiome profiles. “There were all these markers for inflammation and for immune cells kicking into high gear. His body was basically having this moment of, ‘Wow, I’m back in gravity’—these markers in the bloodstream were sometimes 4,000% higher than normal. So we could see that while going to space was hard on the body, returning to gravity was, in some ways, even harder.”

One of the Twins Study’s most surprising discoveries related to telomeres, sections of DNA located at the ends of chromosomes. Normally, as people get older their telomeres get shorter—and researchers had expected to see that happen in space, possibly even faster due to stress and radiation exposure. But in fact—as an investigator at Colorado State University discovered and the Dr. Mason Lab confirmed with new DNA sequencing and analysis methods—Scott’s telomeres got longer, though they reverted to normal after he came home. Why? Researchers don’t yet know. “We need to do a lot more science on this,” says Dr. Cem Meydan, a research associate in the Dr. Mason Lab and a co-first author on the Science paper. “We need to find out why this is happening, and whether we can prevent it or study it for other health-related purposes, such as to fight cancer or aging.”

Dr. Mason and his colleagues emphasize that when it comes to understanding how the human body reacts to being in space, the Twins Study had an obvious and inherent limitation: it had only one subject who actually went aloft. Furthermore, says Dr. Garrett-Bakelman, “this was a single study of one white male; what happens in women, or in people from other racial or cultural backgrounds, we have no idea. Trying to infer anything at all is very difficult without having additional subjects’ data to look at.” And of course, given that the Kelly brothers were NASA’s first (and so far, only) identical twin astronauts, in many ways the study was a one-of-a-kind opportunity. “As a geneticist, I wish every person was a twin or a triplet so we could study them,” Dr. Mason says with a laugh. “It’s unclear if or when this will happen again. It’s going to be hard to match this study anytime soon.” Still, when it comes to figuring out whether humans could survive a mission to Mars or beyond, he and his colleagues call the study’s findings highly encouraging. “Obviously it’s a sample size of one, so it’s hard to make generalized statements—but if we saw similar results in multiple people, I think it bodes well for long-term space travel,” Dr. Meydan says. “Most of the changes we saw can potentially be targeted; in the next five or 10 years, we could develop drugs, interventions or other technology such as shielding for radiation or clothing for reversing fluid shifts in the body.”

Dr. Mason also points out that the Twins Study could have benefits beyond the findings themselves; some of the procedures and analytic techniques its researchers developed could be a boon to terrestrial medicine. “It forced us to be nimble with limited numbers of cells and to sequence really quickly,” he says, noting that their methods could inform rapid diagnosis of infectious pathogens or genetic analysis of a cancer patient’s tumor. Working with some of the same collaborators as in the Twins Study, Dr. Mason’s team also helped pioneer the first-ever DNA sequencing experiments on the International Space Station. Plus, Dr. Garrett-Bakelman says, the study stands as a prime example of how broad scientific questions can be answered through large-scale collaboration. “If you think about it, there were over 80 authors on the Science paper—from multiple institutions, locations and countries—in addition to all the support staff at NASA that helped us do this,” she says. “It was truly a challenging project to complete, and it wouldn’t have been possible without that entire team. That’s how these projects should be done: you bring in expertise from many different areas, think outside the box and piece things together that you would have never thought about unless you were with all those people in the same room.”

With the overarching Science paper out, the Mason Lab has another half dozen publications in progress—continuing to explore what research associate and co-author Daniela Bezdan calls “the most comprehensive and integrated molecular view to date of how a human responds to spaceflight.” For Bezdan and many of her colleagues, just working on a space-related project was a wish come true. The first time she got an e-mail from NASA, she was so excited that she took a screenshot of the header; now, every 10th message in her in-box is from the agency. “We can contribute to making space exploration possible, which could be important for the survival of the human species; it’s something bigger than ourselves,” Bezdan says. “When I think of space travel, I think of three compartments: we are now describing what happens in space; the next step is to understand it—and the third step is to use it for our advantage.”

In Scott Kelly’s 2017 memoir—entitled “Endurance: A Year in Space, a Lifetime of Discovery”—he describes his record-setting tenure on the space station, the longest-duration mission for a NASA astronaut. Toward the end of the book, he contemplates his contribution to the Twins Study, noting that he expects to continue to be a test subject for the rest of his life. “Science is a slow-moving process,” he writes, “and it may be years before any great understanding or breakthrough is reached from the data. Sometimes the questions science asks are answered by other questions. This doesn’t particularly bother me—I will leave the science up to the scientists. For me, it’s worth it to have contributed to advancing human knowledge, even if it’s only a step on a much longer journey.”

This story first appeared in Weill Cornell Medicine, Summer 2019

Weill Cornell Medicine
Office of External Affairs
1300 York Avenue
Box 314
New York, NY 10065 Phone: (646) 962-9476

千层浪视频下载安装 小怪兽官网 富二代f2短视频下载 污软件下载 铁牛视频官网 午夜神器下载安装 午夜神器下载 AVBOBO官网 蜜柚直播下载 蜜柚下载 繁花直播官网 食色短视频下载 年华直播下载 杏吧直播下载 小蝌蚪下载安装 豌豆直播下载安装 合欢视频下载安装 大菠萝官网 鸭脖视频官网 花粥直播下载 咪哒下载 花姬直播下载安装 盘他官网 猫咪视频官网 比心官网 左手视频下载安装 铁牛官网 月亮直播官网 茄子官网 丝瓜草莓视频下载 七秒鱼直播官网 秀色小抖音下载 仙人掌下载安装 水仙直播官网 色秀直播下载 茶馆视频官网 swag台湾下载 红杏视频下载安装 彩云直播下载 花心社区官网 享爱下载安装 心上人直播下载 可乐视频下载 小天仙直播官网 小花螺直播下载安装 小草视频官网 朵朵直播下载安装 7秒鱼直播官网 黄瓜视频人下载安装 小花螺直播下载安装 铁牛下载 九尾狐直播下载 逗趣直播官网 荔枝官网 红楼直播下载 本色视频官网 芭乐下载安装 老王视频下载 佳丽直播视频官网 雨燕直播官网 台湾swag官网 云雨直播官网 食色短视频下载安装 蓝精灵直播下载 左手视频下载安装 桃花下载 黄鱼视频官网 名优馆下载安装 九尾狐视频官网 微杏下载 嘿嘿连载下载 秋葵视频官网 盘他直播下载安装 大番号下载安装 成版人快手官网 名优馆下载 咪哒直播下载 泡泡直播下载 菠萝菠萝蜜视频官网 丝瓜官网 芭乐视频下载安装 桃花官网 盘她官网 九尾狐直播下载 草鱼下载安装 麻豆视频官网 光棍影院官网 十里桃花直播下载 兔子直播官网 性直播下载安装 彩云直播下载安装 桃花直播官网 欢喜视频下载 蜜桃直播官网 夏娃直播下载 葫芦娃官网 草莓官网 Avnight官网 圣女直播官网 杏趣直播下载安装 佳丽直播官网 茄子视频官网 趣播下载 暖暖直播下载安装 福利直播下载安装 泡芙官网 91视频下载安装 草榴短视频官网 迷雾直播官网 一对一直播下载安装 暖暖直播下载安装 猫咪软件官网 夜遇直播号官网 花粥直播官网 麻豆传媒视频官网 美梦视频下载 草榴视频官网 小仙女下载 梦露直播下载安装 彩云直播下载 BB直播下载安装 铁牛视频下载安装 黄瓜下载安装 食色短视频下载安装 草榴短视频官网 梦幻直播下载安装 烟花巷直播官网 逗趣直播下载 乐购直播下载安装 樱桃下载安装 成版人抖音富二代官网 探花直播下载安装 樱桃直播下载安装 七仙女直播下载安装 梦露直播官网 盘她s直播官网 猛虎视频下载 柚子直播下载 梦露直播下载 JOJO直播下载安装 台湾swag下载 泡芙视频下载 大番号下载 妖妖直播下载 梦幻直播官网 铁牛官网 蝶恋花直播下载 蓝精灵直播官网 快猫视频官网 97豆奶视频下载 夜魅直播下载安装 望月官网 硬汉视频下载 暖暖直播下载安装 彩云直播下载安装 年轻人片官网 探花直播下载 红玫瑰直播下载安装 年华直播下载 ML聚合直播下载安装 西瓜直播官网 七仙女直播官网 蜜蜂视频下载 盘他下载 小奶狗下载安装 豆奶抖音短视频下载安装 香草成视频人下载 猛虎视频下载安装 音色短视频下载安装 蜜柚直播下载 樱花下载安装 夜夜直播官网 樱花视频下载 杏趣直播下载安装 污软件下载 夜狼直播官网