Gold, silk, andspices were tangible treasures from past exploration. The Conquistadors wereparticularly good at extracting gold from the local inhabitants. Sir FrancisDrake, before he acquired the title of “Sir,” brought back enough treasure fromhis circumnavigation of the globe to provide more than half the income for theBritish crown for an entire year. The frontiers of space likewise offertreasures won from exploration, treasures that will enrich our lives andenhance our standard of living. These treasures are golden but not gold. Theycontain secrets about the biochemistry of life, and will allow us to increaseour understanding of how life functions. No more silver and gold; from SpaceStation we have blood, spit, and urine, treasures that contain secrets morevaluable than a chest filled with pillaged Aztec gold.
On SpaceStation, we are human guinea pigs for a wide variety of medical experiments.The weightlessness of space offers a biochemical challenge to our bodies, whichdevelop a host of fascinating maladies such as bone decalcification, cataracts,retina swelling, eye focus shifts, smooth muscle atrophy, fluid imbalance,gross weight loss, cardiovascular degeneration, and more. In spite of thesemaladies, humans can thrive in space, proving that as a species, we are a hardylot and can explore places where we were never meant to go.
Themicrogravity of Space Station allows for yet one more experimental variable,offering an amazing and unique environment in which to study human physiology.Mother Earth throughout time has tormented creatures with every possiblevariation of environmental parameters. She has tweaked temperatures from hot tocold, pressures from high to low, chemical compositions from reducing to oxidizingand acid to base, and more. She has thrown stones at us from space and spewedout molten rock and ash from within. The layers of rocks are littered withfossils of hapless creatures that could not make the grade, or, through nofault of their own, were simply caught in the wrong epoch of geologic time. Thehistory of life on Earth is the story of species extinction, a fascinatingthought for those of us that are still here and can contemplate such aconstruct.
With all thischange, with all this process, throughout all the evolution, the one factorthat has been constant for billions of years is the magnitude of Earth’sgravity. Now we can venture off the planet and for the first time in thehistory of life, vary the influence of gravity by a factor of one million. Thefact that we can survive in space is in itself an amazing discovery. We trulyare off in a new frontier, one that life has never seen on Earth, and it is onthis frontier that physiological secrets can be pried from the people who gothere.
As the crew of SpaceStation, we routinely puncture veins, drool on cotton swabs, and urinate inbags. These samples are processed in centrifuges, sprinkled with preservatives,placed in tubes, and stored in MELFI, better known as “the freezer.” Kept at -98° C, these samples are stored for monthsbefore return passage to Earth can be arranged. To ensure safe passage of thesetreasures through the ride back to Earth, NASA has developed a special cold boxthat keeps them frozen for several days, ensuring unthawed recovery by groundcrews, happy life science researchers, and crew members relieved to know thattheir bloodletting was not in vain.
The cold boxesthemselves are an engineering marvel. They are nearly equal in thermalconductivity to a vacuum dewar (Thermos bottle) with only a fraction of themass. They are made from truly space-aged materials; aerogel and Mylar. Aerogelis the most gossamer solid material known. Appearing more like solid smoke,aerogel has a density only 10 times greater than that of air (steel has adensity 7,000 times greater than air) making it one of the best thermalinsulators known, bested only by vacuum. Aerogel is brittle, readily crumbinginto dust. To prevent this eventuality, it is placed inside a skin of Mylar(plastic) film. The air is then sucked out, making this structure as rigid as avacuum-packed bag of coffee (which feels brick-hard until the package isopened). These Mylar-packed aerogel structures can be made into odd shapes,enabling cold boxes to fit in unused pie-shaped spacecraft volumes.
When newtechnology is developed, other unintended uses often surface. Such was the casefor the cold box. Developed for space, it ended up in Antarctica, not forkeeping things cold but for keeping them warm. In 2006-2007, I had the goodfortune to live in a tent about 200 miles from the South Pole during ascientific expedition to Antarctica as part of a meteorite gathering teamcalled ANSMET (Antarctic Search for Meteorites). The conditions found inAntarctica preserve and concentrate meteorites, a discovery not realized untilthe early 1970’s. They accumulate on the surface of the blue glacier ice, andbecause they appear as strongly contrasting black specks from a distance, theycan be recognized from afar and gathered like cosmic Easter eggs. For the last30 years, annual expeditions working during the short Antarctic summers havegathered over 20,000 meteorites. During our six-week stay, we advanced thisnumber by 850.
Living in atent under primitive conditions, the ambient temperature danced around -20° C throughout the continuous daylight ofthe Antarctic summer day. Including wind chill, the effective temperature was-40° C. At such temperature levels, it does not matter what scale is used.In our tents, the floor temperature stayed at -20° C and the chimney varied from -20° C to +20° C, depending on whether the stove waslit. Any water-based substance became a frozen lump. Most electronic devicesrefuse to operate under these conditions; from batteries that do not makesparks (lithium-ion batteries do not like to be charged if less than 0° C), LCD displays that give only blankstares, or hard drives that do not turn at the right speed.
The Antarctichot box in its former life was an engineering test article used to make thermalmeasurements for the design of the spaceflight units. Having served thatpurpose, I found it in a dank NASA cabinet, itself in cold storage andseemingly of no further use. Brought out from retirement, this high-tech spacecooler found itself strapped to a Nansen sledge, pounding through the Antarcticinterior over snow structures known as sastrugi. In a sea of cold, it offered asmall oasis of warmth. We also kept our Tabasco sauce and sourdough starter inthe hot box, demonstrating the value of having small comforts when living onthe frontier.
Thus we beholdthe new treasure garnered from the frontier of space. Not gold or spices, butknowledge. Knowledge always has value, even if we don’t immediately know orrecognize it. The real treasure of new exploration is the larger knowledge baseand the expanded imagination we develop from it. In time, all knowledge showsitself to be useful in some way. The fact that today it is difficult topinpoint the value of space exploration shows that it is truly venturing into terra incognita, unknown territory.
Don’s blog also appears atairspacemag.com.