When it comes finally time to settle Mars, the most terrifying sound might not be *RRRIP* or ‘I'‘m sorry, Dave, I don'‘t WANT to turn the carbon dioxide scrubbers back on.’ It might well be *SNAP*. That is, if we can't figure out solutions to some of the issues astronauts face in long-term space flight.
It will take astronauts nine months to get to Mars using current technology, every month bringing with it a sure and steady loss of bone mass as osteoblasts, the cells that are supposed to lay down new bone deposits, slowly stop showing up for work. As a result, after touchdown, astronaut bones could break more easily, with the nearest hospital 249 million miles away. If humanity is to become a star-dwelling race, we have to first come to grips with the quiet treachery of our skeleton.
If you’re like me, you probably thought that bone loss was a thoroughly Fixed Problem. Just give the astronauts some calcium supplements, some spring-based exercise equipment, maybe one of those spinning space stations you get on Arthur C. Clarke covers – problem solved.
Welllll, not quite.
To find out why, we need to look at the work NASA scientists have been doing on the physiological effects of microgravity, which happens to be the specialty of biomedical engineer Dr Mamta Patel Nagaraja. You might know her as the head of the Women@NASA program, a magnificent resource for demonstrating the breadth and scope of the women scientists and engineers and communications experts who work at NASA, and we’ll certainly talk about that in a bit, but before she was the woman behind Women@NASA, she was a triple crown engineer pushing forward our knowledge about the deep mystery of how human organisms fare in space.
She was born in California in 1979 to a pair of hard-working and deeply self-sacrificing parents who had just immigrated to America from India the year before. She was the third of five siblings, three of whom ultimately became scientists. Nagaraja’s tales of her youth are straight out of a Norman Rockwell painting – the siblings toting encyclopedias into the forest on expeditions to identify the flora and fauna they found there, or checking gigantic puzzles out of the library to do them at home as a family over the course of weeks. The three middle children were science nerds who helped and inspired each other, and Nagaraja’s ultimate career is a fantastic blending of her own early love of space and engineering with her sisters’ interests in genetics and physiology.
When her parents found work running a small motel, the children were drafted to help with the maintenance work, regardless of gender, and so Nagaraja picked up skills with jackhammers and air conditioning units, sewer lines and refrigerators, that would serve her well when she went to college and did more or less everything you’re told not to do by conventional wisdom.
The Standard Advice says find a field early in college, specialise deeply in it, and then ride that specialty through your career. But Nagaraja’s interests, understandably, were too broad to be winnowed down to just one field. So, she did her Bachelor’s in aerospace engineering, then switched fields for her Master’s to mechanical engineering, then switched again for her doctorate to biomedical engineering. So, for all the students out there who feel that they have to decide early, and stay with that decision no matter what happens, I advise you to print out a photo of Dr Nagaraja and write in bold letters under it, ‘Change is Okay.’’
Of course, it helps a tad if you’re a polymath genius who comes from a supportive family of science enthusiasts and who grew up with daily practical engineering experience as a matter of course...
Anyhow, let’s get back to those treacherous permanent residents, our bones. Nagaraja was in a position to concentrate her various skills on a multi-disciplinary problem that involved her old love of space and space travel with her skills as a mechanical and biomedical engineer. It had been known since Millie Hughes-Fulford’s work in the mid Nineties that the slowing down of new bone growth had something to do with gravity’s impact on gene expression. Remember, it's not enough to just have the genes that allow for new bone growth. They also need to be expressed, which is to say the instructions have to be copied down into mRNA and then put into action. Somehow, without gravity, the expression of the genes that lead to osteoblasts laying down new bone growth was being affected, meaning that the problem was more fundamental than we had thought.
The issue with studying the effects of microgravity on humans is, of course, that there aren't many humans who live in microgravity. Statistically speaking, the number of people who have lived any amount of time in space is miniscule, and the number who are currently living there positively dreams of minisculity. So, other ways have to be found to study how gravity influences gene expression. Nagaraja uses studies of cells held in simulated microgravity (a magnetic field can do the trick) to see how prolonged exposure to different levels of gravity impacts gene expression, and how different techniques might improve that expression.
So far, it looks like the answer might lie in including a vibrational element to the astronauts’ exercise regimen in space, since cells appear to respond to vibration similarly to how they respond to the force of gravity at the level of gene expression. Nagaraja worked on the benefits of whole body vibrational platforms with Dr Clinton Rubin as a graduate student, and the results have been promising enough to merit consideration as a payload in a future NASA space mission.
Meanwhile, because you are doubtlessly not feeling quite under-accomplished enough, there are all of the other things Nagaraja has achieved in her life. She was an instructor and flight controller at Johnson Space Center, training astronauts in the operation of their shuttle. And then there is the important job of running the Women@NASA program, bringing to the world the stories of NASA’s great and long history of women researchers and workers in a way that is both exciting and inspiring to a new generation sitting at their desks and dreaming of stars. For any girl in a classroom feeling alone in her love of science, there are columns and columns of role models there to search through and identify with, a great digital edifice declaring You Belong. You can also find there information about NASA’s middle school mentoring programs, NASA GIRLS and NASA BOYS.
Asked about her plans for the future (she is a mere 42 now), she looks forward to many more years of work at NASA (including a thin chance to actually go to space herself – fingers crossed!) and then perhaps a change of pace to, you guessed it, developing knee replacements for those who can't currently afford one or developing inner city clean water supplies both here in America and in villages in India where her parents grew up. She has trained our astronauts, helped remove a thorn from the paw of our future space colonisation hopes, and desires nothing more than to cap it all with work to improve access to clean water, in a life lived with a deep sense of commitment to employing her brain for the good of others. If you need any more proof of how much we stand to lose if we close ourselves off to the world, its hopeful and hard-working people, and their children, look no further.
FURTHER READING:
If you'd like to read more about women astronomers like this one, check out my History of Women in Astronomy and Space Exploration, which you can order from Amazon, or from Pen and Sword US or UK.
