“Astronaut” is one of those professional titles like “Knight” and “Olympian” that will never stop being cool. It is a staple of kids’ fantasy professions. Even in adulthood, it is the type of title that when spoken aloud demands your immediate attention, while also kick-starting your own deep desire for adventure.
Just last week, NASA announced their latest round of astronaut trainees, class of 2013. Eight badass Americans—a smattering of doctors, scientists, and military personnel hailing from across the country—will start the long path that, perhaps in five or ten years, may culminate in a trip to space, and the ever-prized “Astronaut” designation.
The recently released roster made headlines because fifty percent of the accepted applicants, or 4 of them, are female. In this male-dominated profession, a single accepted female astronaut candidate is reason enough to cheer. But four, well, that is reason to party!
The first women astronaut, named Valentina Tereshkova, ventured into space in 1963, relatively early in human space flight history. She was from the Soviet Union. So was the second woman in space, Svetlana Savitskaya. It took around twenty years for the United States to catch up, casting the curly-haired Californian, Sally Ride, into space in 1983.
Instead, I want to talk briefly about the risks associated with being astronaut. We all know it is difficult to become an astronaut. It is an elite club. The badass eight were selected from an applicant pool of more than 6,300 candidates, the second-largest American candidate pool ever. There were several rounds of cuts. And, even now, there is the chance that none of these selected men and women will even land a mission.
But once you are officially an astronaut, whether a man or women, the goings only gets tougher. The human body is perfectly equipped for on-earth activities. Our bones, muscles, and organs are sculpted and conditioned by gravity. In space, the lack of gravity, called antigravity, causes the body to go haywire. And the longer you are in space, the more ways, it seems, the body stops working.
This is especially grave considering that future human space flight missions to asteroids or even Mars are long missions. Forget two-week vacations to space, we are talking years!
And for these grand-scaled missions, we will need not only new, fancy space crafts, but also a better understanding of how the human body behaves in space—and, ideally, solutions for some known problems.
Last month, on my visit to the NASA Johnson Space Center in Houston, Texas, as part of a NASA Social (you can read more about that visit, here), I got a brief update on the latest research concerning common health issues plaguing astronauts.
So, what are the different ways that antigravity affects the body, you ask? See below. (Note: These conditions are not listed in any particular order.)
Loss of Vision – As of June 2012, 15 International Space Station (ISS) long-duration mission astronauts have suffered vision problems, ranging from farsightedness, to tiny white spots on the eyes called “cotton wool spots,” to swelling of different parts of the eye. Most of these issues result in difficulty focusing the eye, i.e. one’s vision becomes blurry.
For some astronauts, the symptoms were temporary. For others, they still persist. It is unclear what exactly is causing these problems and in fact, there may be several factors. But one current theory that can partially explain the symptoms is space exerts extra pressure in the skull, called “intracranial pressure,” that in turns messes with the eye. This is a problem that affects long-duration astronauts only.
Muscle Loss – Moving around on Earth, we are constantly using our muscles, whether we are cleaning dirty dishes off the kitchen table to walking to the subway station. But up in space, under microgravity conditions, out muscles are perpetually less strained. When our muscles are not worked, they languish.
While astronaut may not need these muscles up in space, they need them back home. Every astronaut experiences some degree of muscle loss, whether they are up in space for a few days or months. According to NASA, astronauts can lose 20 percent of muscle mass on a spaceflight lasing five to eleven days.
To counteract muscle atrophy, the technical term for degrading muscles, ISS astronauts spend at least two and a half hours of their day working out: running, biking, and/or weight lifting. More specified training has dramatically reduced the levels of astronaut muscle loss, but not entirely.
Bone Loss – Perhaps the most devastating and widespread impact of space flight is bone loss. Bones are constantly in a state of regeneration. It is incorrect to think of them as stable, concrete blocks. Instead, they are made of many cells are constantly dying and then rebuilding. But in space, this system breaks down. Bone cells keep dying, but new ones do not grow back as quickly, resulting in swiss cheese-like bones. Essentially microgravity produces similar bone loss to those suffering from osteoporosis here on Earth.
In response, scientists have tested different weight training regimes and calibrated astronaut diets. It is known that vegans have lower rates of osteoporosis. Taking a page out of their cookbooks, astronauts now have greater proportions of fruits, nuts, and veggies in their in-space meal plan, and less meat and salt. Preliminary results show that these changes are indeed resulting in greater bone cell regeneration. But whether these new cells are just as “strong” is yet to be seen. Starting this September, new ISS studies will continue looking into this issue.
For more information about NASA’s astronaut health research, go here. There will also be another NASA Social dedicated to this topic next month, July 17, 2013, back in Houston. And for the truly inspired, go here for information on how to become America’s next awesome astronaut.