Jelly on Both Sides

Whenyour slice of bread falls on the floor, everyone anxiously looks to see if itlanded jelly side up or jelly side down. Simple probability gives a 50-50chance either way, but it seems more correlated to the difficulty of cleaningthat particular section of flooring.

Onspace station the probabilities are still the same, but the results aredifferent. I fumbled my bread after spreading a generous layer of my favoriteconcoction, peanut butter and honey. It sped toward the overhead panel and hitit before I could intervene. Fortunately, it landed jelly side out (it’s interesting how many figuresof speech have gravity-oriented references), so the 50-50 odds were in my favorthis time.

Unfortunately, it ricocheted and sped off in a different direction.I noticed that the angle of incidence equaled the angle of reflection. Myearth-honed intuition anticipated a different motion, so I was not able to keepup with the errant slice. Like a real-life version of the game “asteroids,” itwent on to hit a second panel. Jelly side was out again, so the 50-50 statistics were still in my favor. One moretime my hand was lagging the trajectory. Like failing to flip heads three timesin a row, the third collision was jelly side in, which immediately halted all motion. And just like on Earth,the outcome seemed related to the difficulty of cleaning the landing zone.After having hit two easy-to-clean aluminum panels, it landed on a white fabriccovering on a patch of Velcro pile.

Thefatalist in me accepts the inevitable Zero-G result of landing jelly side“down,” so I decided to make sure the probability would always be 100%.Realizing that the bread is merely a vehicle for conveying peanut butter andhoney, I decided to spread it on both sides. In weightlessness, it’s easy tobalance your slice on its edge so that it can be parked on the galley tablewithout any fuss. And the result is pure tastebud heaven. I do it this waybecause I am in space, and I can.

Don’s blog also appears at

A Lab for Science, and for Thinking

The International Space Station was conceived and constructed through the cooperation of fifteen nations. Now, with it’s construction complete, we can focus on how best to use it.

We have built a laboratory located on the premier frontier of our era. Our Earth-honed intuition no longer applies in this orbital environment. On frontiers, things do not behave the way we think they should, and our preconceived notions are altered by observations. That makes it rich in potential for discovery. The answers are not in the back of the book, and sometimes even the questions themselves may not be known.

Getting ready to insert biological samples in the Minus Eighty Laboratory Freezer for ISS (MELFI-1) in the Kibo lab.

On the Station we can use reduced gravity as an experimental variable for long periods of time. We have access to high vacuum, at enormous pumping rates. (The rate at which space can suck away gas, hence its ability to provide a region devoid of molecules, far outpaces anything we can do on Earth.) We are beyond the majority of our atmosphere, which lets us touch the near-space environment where solar wind, cosmic rays, and atomic oxygen abound. Such cosmic detritus, unavailable for study within our atmosphere, holds some answers to the construction of our universe and how our small planet fits into the picture.

The Station as a laboratory offers most of the features that Earth-borne laboratories have, including a good selection of experimental equipment, supplies, and a well-characterized environment (temperature, pressure, humidity, gas composition, etc.). There is generous electric power, high data-rate communications, significant crew work hours (the fraction of hours spent on science per crew day on Space Station is commensurate with the fraction for other science frontiers such as Antarctica and the deep ocean), and extended observational periods ranging from weeks to years. All this is conducted with a healthy blend of robots and humans, working together hand-in-end-effector, each contributing what each does best. Only on Earth is there a perceived friction between robots and humans.

In this orbital laboratory, we can iterate experimental procedures. We can try something, fail, go back to our chalk board, think, (we now have the time for this luxury) and try it all over again. We can iterate on the iteration. We now have continuous human presence, and time to see the unexpected and act upon it in unplanned ways. Sometimes these odd observations become the basis for studies totally different from those originally planned; sometimes those studies prove to be more valuable. And on this frontier the questions and answers mold each other in Yin-Yang fashion until reaching a natural endpoint or the funding runs out, whichever comes first. This is science at its best, and now, for the first time, we have a laboratory in space that allows us to do research in a way comparable to how we do it on Earth.

So what questions are ripe for study on the Station? What possible areas of research might bear fruit? We have a few ideas.

One area is the study of life on Earth. Life has survived for billions of years, during which temperatures, pressures, chemical potentials, radiation, and other factors have varied widely. Life always adapts and (mostly) survives. Yet there is one parameter that has remained constant for billions of years, as if our planet was the most tender of incubators. Now for the first time in the evolution of life, we humans can systematically tweak the gravity knob and probe its effect on living creatures. And we can change the magnitude of gravity by a factor of one million. Try changing other life-giving parameters, perhaps temperature, by a factor of one million and see how long it takes a hapless life form to shrivel up and die! The fact that gravity can be changed by many orders of magnitude and life can continue is, in itself, an amazing discovery. So now we have a laboratory to probe in-depth the effects of microgravity on living organisms.

The discovery of fire (or rather its harnessing) was a significant advance that allowed humans to transcend what we were to become what we are now. Well before Galileo and Newton dissected the basic formulations of gravity, humans intuitively understood that heat rises. We empirically learned how to fan the flames. But fire as we know it on Earth requires gravity. Without gravity-driven convection, it will consume its local supply of oxygen and snuff itself out as effectively as if smothered by a fire extinguisher. Questions about fire (up here we prefer the term “combustion”) are ripe for a place where we can tinker with the gravity knob.

Another invention, the wheel, literally carried us into the Industrial Age. Ironically, that particular tool is rendered obsolete on a frontier where one can move the heaviest of burdens with a small push of the fingertips. In space the problem is not how to move an object, but how to make it stay put. Perhaps the invention of the bungee cord and Velcro will be the space-equivalent to the development of the wheel on Earth. Such shifts in thought and perspective, some seemingly minor, happen when you observe the commonplace in a new and unfamiliar setting.

We are now told that we may only be seeing about 4 percent of the stuff that our universe is made of (which raises the question, what is the other 96 percent?). Some questions about fundamental physics can only be made outside our atmosphere or away from the effects of gravity. The International Space Station, contaminated with human-induced vibrations, may not be the ideal platform for these observations, but it is currently in orbit and is available to be used. Many of these experiments are like remora fish, latching onto an opportune shark for a sure ride instead of waiting for the ideal shark to swim by. And we pesky humans, even though we cause vibration, occasionally come in handy when some unexpected problem requires a tweak, a wrench, or simply a swift kick.

Although we have preconceived ideas about how the International Space Station can be utilized, benefits of an unquantifiable nature will slowly emerge and probably will be recognized only in hindsight. The Station offers us perspective; it allows us to question how humans behave on this planet in ways that you can’t when you live there.

The Expanding Universe of Trash

It is not surprising that the humble garbage can, essential for Earth-borne civilization, is likewise essential for space station. Unlike the kitchen wastebasket, an omnivore that will eat just about any trashy thing, on space station our wastebaskets are picky eaters.  We sort our trash into a number of different categories different from the standard earthly recycle bins of paper, plastic, and glass.  The main categories are: dry trash (paper towels, food packaging, empty drink bags, paper items, etc.), wet trash (pouches and wrappers with food residue), spent batteries, life support systems expendables (fluid sample bags, toilet hoses, connectors, etc.), experimental expendables (used medical supplies, containers filled with leftover nasty things, etc.), and toilet waste (sealed buckets of you know what).  Some of our trash items have bar codes and serial numbers and require bookkeeping paperwork at the time of disposal.  Like happens at home, sometimes an item is tossed that is later discovered essential so we go orbital dumpster diving for its recovery.  Like passing through a miniature asteroid belt, in weightlessness such an operation can create a cloud of floating debris that is challenging to put back into its container.


One characteristic of an orbital trashcan is that it is always full.  When I change out a trash bag, within a short time it is once again full.  Like a gas expanding into a vacuum, items placed inside expand into the available volume thus giving the appearance of a full bag.  Unlike an ideal gas expanding into a vacuum, here the change in entropy is not zero.  Placing new items into such a bag is really an act of compression.  The trash is squeezed and compressed until the placing of one more item requires greater strength than your arms can supply.  At that point the bag is sealed with duct tape.  The final disposal is via Progress, the spent Russian cargo vehicle (and now we also can use ATV and HTV, the European and Japanese cargo vehicles).  The ultimate disposal of our garbage is thus via deorbital cremation.

Flying without Wings

During interviews from space station with school children I am often asked what on Earth I miss the most.  On one occasion a little girl asked a most astute question, “What from space will you miss the most once you return to Earth”?  I had to think for a moment.  Was it the views of Earth, a blue jewel surrounded by inky blackness, the heavens filled with stars that don’t twinkle, or perhaps the aurora, pure occipital pleasure seen on the length scale of half a continent?  I decided it was none of these.  Such wonders can be experienced in some form from Earthly perspectives.  What is truly unique to living in orbit is a byproduct of being weightless.  Here I can fly.  I can fly without wings dictated only by Newton’s laws of motion without the complications of aerodynamics.


As subjects of Earth, we grow up with no innate knowledge of maneuvering in weightlessness.  This is a skill that has to be learned on the job.  In a matter of minutes, we can learn to move about but to gracefully conduct ourselves takes a few weeks.  During my first expedition, after a month I thought, “Wow, I am really getting good at this”.  Then another month went by and I would think, “Last month I thought I was really good but now I am really getting good”.  I found this pattern repeated over the six month mission.  When I returned to space station as a space shuttle crew member on Endeavour, our mission was only 16 days, a mere flash in the pan by space station standards.  Sixteen days is barely enough time for your bowel to become regular let alone learn how to translate in weightlessness.  Newly arrived Shuttle crew members typically would miss a hand rail and bounce off of a rack panel with the same grace as an albatross coming in for a landing.  There would be a cloud of items knocked off of their Velcro wall tacking in their wake.  The station crew members were constantly following our shuttle crew picking up the flotsam.  One station crew member mocked, “Next time before the shuttle arrives I will have to kid-proof the stack”.   


To improve your translation skills, it helps to apply some basic concepts of physics.  When flying like “Superman”, the first and most natural method for beginners to translate, your arms are outstretched in front thus grasping onto any fixed object in which to give a little push or pull as well as offering a measure of security for protecting the tender parts on top of the head.  But this is not the best way to fly.  In this position your center of gravity is located somewhere around the belly button so controlling motion with outstretched arms also imparts rotational components and complicates the movement.  Beginners flail with these yaw and pitch motions and struggle to compensate for their unwanted effects.  Thus I learned the best way to fly is head first with arms at your side like “Ironman”.  Pushing and pulling from this position goes nearly through your center of mass, thus does not impart rotation.  On space station Ironman becomes your role model for flying, leaving Superman for the comic books. 


With practice I progressed from flying like Ironman to fly-walking.  Fly-walking looks like normal walking with the body “standing upright” and motion perpendicular to the chest.  In fly-walking your motion is controlled by the legs through tactful forces exerted through the feet when hooked under a deck mounted handrail.  This motion does not seem possible, however; when pressed into a new environment, humans readily discover, learn, and adapt.  Fly-walking offers a real advantage because it frees your arms for carrying loads.  


There is recreational flying.  This is fun flying, perhaps in a gymnastic pike, an iron cross, or a cannon ball.  You try to shoot down a module corridor without touching anything thus having a visceral experience with the First Law of Motion.  We fly like this for no reason other than you are in space and you can.  It is the equivalent of a kid skipping to school.  In the frontier we once again become school kids.

Absence of g

He flies through the air with the greatest of ease 

goes the daring young man, without his trapeze 

Drifting around, unconstrained by his girth 

free of the weight he acquired by birth 

A place where you won’t be skinning your knee 

where the biggest problem is “How does one pee?” 

(it is best to avoid preflight coffee or tea) 

Like flying in dreams, which you know can’t be 

yet it’s real as life, in the absence of g 

The World Through a Looking Glass

Looking through the cupola windows on Space Station, it’s only naturalto reflect upon who we are and where we fit into the world below. Likesomething out of Alice in Wonderland, this orbital lookingglass can be both a window through which to observe the jeweled sphereof Earth and a mirror that (sometimes, depending on your viewing angle)shows you a translucent reflection of yourself superimposed on theplanet.

From orbit, the more you know about our planet, the more you can see.You see all the geological features described in textbooks. You seefault zones, moraines, basins, ranges, impact craters, dikes, sills,braided channels, the strike and dip of layered rocks, folding,meanders, oxbow lakes, slumps, slides, mud flows, deltas, alluvial fans,glaciers, karst topography, cirques, tectonic plates, rifts zones,cinder cones, crater lakes, fossil sea shores, lava flows, volcanicplumes, fissures, eruptions, dry lakes, inverted topography, lattericsoils, and many more.

You see clouds of every description and combination: nimbus, cumulus,stratus, nimbo-cumulus, nimbo-stratus, cirrus, thunderheads, andtyphoons, sometimes with clockwise rotation, sometimes withcounter-clockwise. You notice patterns: clouds over cold oceans lookdifferent than clouds over warm oceans. Sometimes the continents are allcloud-covered, so you have no recognizable landmass to help you gaugewhere you are. If you see a crisscross of jet contrails glistening inthe sun above the clouds, you know you are over the United States.

Lightning storms flash like gigantic fireflies looking for mates halfa continent away. You see patterns on the ocean surface, swirls andvortices on large scales, wave diffraction patterns around capes,solitary waves forming long lines out in the middle of nowhere, andrivers that look like they are spilling milk chocolate into turquoiseoceans.

You see light-scattering phenomena of all kinds—at sunrise, atsunset, across the terminator, 16 times a day. You see crepuscular rays,forward reddened lobes, off-axis blue lobes, and corona halos. Withbinoculars you can count six distinct layers in the atmosphere, with theouter one seemingly fading into fuzzy blackness.

The aurora is nothing short of occipital ecstasy. It is alwaysmoving, always changing, and like snowflakes, no two displays are thesame. The glowing red and green forms meander like celestial amoebascrawling across some great petri dish. One time our orbit took usthrough the center of an auroral display. It was as if we were in aglowing fog of red and green. Had we been shrunk down and inserted intothe tube of a neon sign? It looked like it was just on the other side ofthe windowpane. I wanted to reach out and touch, but of course Icouldn’t. Afterwards, I had to clean nose prints off of the window.

You catch an occasional meteor while looking down at Earth.You see stars and planets in oblique views, next to Earth’s limb. Andthey do not twinkle. Perchance you might spot a ragged shadow from atotal solar eclipse projected onto Earth. Amazing, it looks just like itdoes in the textbooks! You have a godlike view of the finer details ofshadowy projections onto spherical bodies. You see space junk orbitingnearby. Sometimes it flickers due to an irregularity, catching light asit rotates. An overboard water dump produces a virtual blizzard in thesurrounding vacuum. Like strangers passing in the night, you see othersatellites flash brilliantly for a few seconds, then fade into oblivion.

Jungles are the darkest land features you can observe in fullsunlight. They are so dark that you need to open your camera lens toobtain a proper exposure. If there are clouds partly shrouding yourview, you can be fooled into thinking you are over the ocean. Only whenyou notice rivers with braided channels and meandering loops ofchocolate brown do you realize that it is jungle and not water.Farmland, rich with vibrant crops, is different. Farmland is bright,much brighter than the jungles. Here nature is giving us a clue as tothe efficiency of light capture by plants.

The impact of humanity on Earth is humbling from orbit. Our greatestcities appear to the bare eye as minor gray smudges on the edges ofcontinents—they could be the fingerprints of Atlas, from the last timehe handled the globe. They are hardly distinguishable from volcanic ashflow or other geologic features. If you didn’t know it was a city, itwould be difficult to conclude it was the result of human design. Underthe scrutiny of the telephoto lens, things appear different. Like antsmoving crumbs of dirt, we are slowly changing our world. You realizethat Earth will do just fine, with or without us. We are wedded to thisplanet, for better or for worse, until mass extinction do us part.

Cities at nightare different from their drab daytime counterparts. They present a mostspectacular display that rivals a Broadway marquee. And cities aroundthe world are different. Some show blue-green, while others showyellow-orange. Some have rectangular grids, while others look like afractal-snapshot from Mandelbrot space.

Patterns in the countryside are different in Europe, North America,and South America. In space, you can see political boundaries that showup only at night. As if a beacon for humanity, Las Vegas is truly thebrightest spot on Earth. Cities at night may very well be the mostbeautiful unintentional consequence of human activity.

This looking glass incites your mind to ponder the abstract. Throughthe window, you explore the world. In the mirror, you reflect upon yourplace within it and the reasons we explore. Is it fundamentally aboutfinding new places to live and new resources to use? Or is it aboutexpanding our knowledge of the universe? Either way, exploration seemsfundamental to our survival as a species. After all, if the dinosaurshad explored space and colonized other planets, they would still bealive today.

The Eye of Issyk Kul

Kyrgyzstan is wedged in the mountainous wrinkles between Kazakhstan andChina, created long ago when the land mass we now call India, propelled by platetectonics, slammed into the Asian plate. Living there are a proud people with arich history, surrounded by natural, high-altitude beauty.

Issyk Kul

Out of numerous Kyrgyz lakes, one in particular stands out—Lake Issyk Kul.When seen from orbit, Issyk Kul appears to be a giant eye, looking at us lookingdown at it. The snow-covered mountains become aged eyebrows. The lake itself,having a fairly high salt concentration, does not typically freeze over, thusreflecting wintertime light in such a way as to form a “pupil” that seems totrack us as we orbit overhead.

Whisker Cleaning Time

I have never beenable to shave with a safety razor without slicing my face, so I use a rotaryelectric razor instead. In weightlessness they work just as well, and thewhiskers are captured inside the shaving head. But how does one clean out the whiskersin weightlessness? On Earth, you simply open the head and shake them out. Doingthat up here would be a disaster. So once a week, when vacuuming theaccumulation of lint, dust, and detritus against the air inlet filters, Ivacuum my razor. I hold the vacuum cleaner hose between my legs, and use bothhands to carefully open the shaving head in front of the suction. A cloud ofwhiskers jumps out, appearing like a miniature asteroid field, then quicklydisappears into a black hole, with no chance of escape.

The Sweet Smell of Molecules

A vacuum is a condition that is nearly devoid of molecules, and space is a molecular desert that makes the Empty Quarter of the Saudi Arabian peninsula seem like an oasis in comparison. But the space vacuum still has some molecules—residue from galactic processes, solar wind or atomic detritus spalled off from our atmosphere. And molecules, typically floating in the surrounding air, can be sensed via smell.

To talk about the smell of space makes no sense at all. Even if we had space-adapted noses, there is no air to transport the trace molecules. However, space does have a definite smell, and we can smell it in a roundabout way.

I have had the pleasure of operating our space station airlock for many crewmates while they went on spacewalks. Each time, when I repressurized the airlock, opened the hatch, and greeted my tired returning friends, a peculiar essence drifting about the newly repressurized chamber tickled my olfactory senses. I noticed that the smell was coming from the spacesuit fabric, the tools, and any other equipment that had been brought inside. It was more pronounced on fabrics than on metal or plastic surfaces. It most definitely did not come from the air lines that pressurized the chamber.

That’s me with John Herrington in the Quest Airlock during the STS-113 Endeavour mission to the International Space Station in 2002.

At first I couldn’t quite place the smell. The best description I can come up with is that it’s rather pleasantly metallic. It brought me back to my college summers, when I used an arc welding torch to repair heavy equipment for a small logging outfit. It reminded me of sweet-smelling welding fumes. To me this is the smell of space.

Reptiles have smell sensors located not within their nasal passage, but on the roof of their mouth. They smell by waving their moist tongue in the air, then pressing it against the roof of their mouth, thus indirectly transferring molecules from the air to the olfactory sensors. It occurred to me that I was smelling the essence of space through an indirect transfer, in a manner not unlike that of our lizard friends.

Perpetual Twilight


Twice a year, near the winter and summer solstices, the orbit ofspace station nearly parallels the terminator—the fuzzy line separatingday from night on the surface below. For a period of about a week, welive in what seems like perpetual twilight, being in neither fulldaylight nor full night. Our orbit follows the terminator, so that spacestation is constantly sunlit. From this vantage I can see both day andnight simply by swiveling my head from left to right. But the night isnot really dark, and the day is lit by low-angle rays from the Sun.

Geographic relief casts long shadows, and imparts stark contrast tofeatures that are typically overlooked. Small ripples in sand dunes makehigh contrast striations across the bright desert landscape that looklike Nature’s way of drawing with pen and ink. Geographic relief playstricks on you. First you see the Grand Canyon as this deep scar.Blink your eyes and it is now a rippling bump. Thunderstorms castshadows that look like they come from some new type of ray beam weapon.Airliners, their path defined by contrails, leave glimmering lines likesnail trails in the morning dew. The gardens of Earth appear to havequite an infestation of snails.

The Moon sets in a counterintuitive way. From this vantage it movesnearly parallel to the horizon. Once I saw it slowly set, only toreappear in a few minutes. The Moon was visible for nearly the wholeorbit.

The night side is equally fascinating. The atmosphere on edge glowswith a vibrant electric blue. Did van Gogh paint this scene? I can seeat least five, maybe six distinct layers of blue—perhaps a visualdisplay of the classic atmospheric strata. Just past the terminator,rays of sunlight can be seen projected above the darkened limb of theEarth.

The most striking aspect of our atmosphere is not the palette ofelectric blue colors but the thinness of it all. Our atmosphere is adiaphanous veil; thin, fragile, transparent, and the only thing thatprotects us from the harsh vacuum of space. Too much atmosphere, and theplanet is choked and suffocated. Too little, and it is exposed to theharshness of cosmic space. My vantage on the station gives me a deepappreciation of this fact.