AirSpaceMag.com

Nature has a vivid imagination, more so than any human. By venturing into unknown territory, discoveries will be made that tickle our imagination and enrich our minds.  On the frontier, you can once again see the world through the eyes of a child.

I wonder why the sky is up, and why the stars abound?
And why the Sun comes up each morn, and why the Earth goes ’round?
I wonder what the Sun on Mars, would bring at dusk and dawn?
I wonder what two moons would say, from Earth lit sky when Sun is gone
I wonder if Mars mountain crags would be a sight to hold?
I wonder if I’d dare to climb, how could I be so bold!
I wonder when Man’s mind will grow, and cease to be so small
I wonder when we’ll venture forth, I hope before we fall
I wonder if we’ll never dare, to reach up through the sky
Forever doomed to live on Earth, and this, I wonder why?

A double fisheye view

Self-portrait, with cameras.

I often hear someone remark, “The chances of X happening are one in a million,” where X could be any number of rare events such as winning the lottery. When numbers become as large as a million, it is difficult for my mind to comprehend them—as compared to tangible objects that I can see, touch, and count. A thousand million makes a billion, making that number a thousand times more abstract.

I float in the Space Station cupola, looking out the seven windows of this faceted transparent jewel, observing the nighttime Earth. There are now seven billion people who call this planet home. It occurred to me that there are only six people who can say the same for space right now. What a privilege it is to be one of those six.

A view from the ground during the San Antonio Astronomical Association's laser-flashing of the ISS last month. Photo by Robert Stepp.

There’s more to that recent Space Station flash by an amateur astronomy group than may have met the eye, so here are a few more details.

Lasers produce not only monochromatic light, but also a unique intensity profile. If you take a cross-section of the beam and plot the intensity, it is far from uniform. Mathematically, the profile takes the form of what’s known as a Gaussian distribution, or bell curve. This vastly simplifies calculations for the beam propagation. The divergence of a laser beam—how quickly it spreads—is much less than for an equivalent beam of broad-spectrum white light, such as the one produced by a spotlight.

If you project a typical two-millimeter-diameter laser beam 400 kilometers, or 240 miles (the altitude of Space Station), the resultant beam diameter is about 1 kilometer. This has two significant impacts. First, precise tracking is needed to keep this 1-kilometer spot on the 200- meter cross-section of Space Station from a distance of 400 kilometers. This is no small feat, as the Station is a moving target in the sky. Second, the intensity of the laser beam falls in proportion to its cross-sectional area. In this case, an initial beam of 2 millimeters expanded to 1 kilometer, reducing the intensity by a factor of about 250 billion. The rated output of the laser also will be reduced by this factor when viewed by the crew on Space Station, and so does not pose a threat to human eyesight. Please note the calculations are different when flashing an airplane, something that must be avoided. For the Space Station flash, the San Antonio astronomers used a one-watt laser and a gang of two 850-watt mercury-argon arc lamps. Both were clearly visible from my vantage point.

Here is my attempt to capture a Station re-boost last weekend using ATV (Automated Transfer Vehicle) propellant.

Notice that as the burn progresses, a halo of exhaust accumulates that is visible when the thrusters fire for thrust corrections.

Seeing as how April is National Poetry Month….

Space is My Mistress

Space is my Mistress,
and she beckons my return.
Since our departure I think of you
and yearn to fly across the heavens arm in arm.
I marvel at your figure,
defined by the edges of continents.
You gaze at me with turquoise eyes,
perhaps mistaken for ocean atolls.
You tease me to fall into your bosom,
sculptured by tectonic rifts,
only to move away as if playing some tantalizing game.
Time and time we turn together,
through day, and night, and day,
repeating encounters every 90 minutes with a freshness,
as if we have never seen our faces before.
We stroll outside together,
enveloped by naked cosmos,
filled with desire to be one.
So close,
you sense my every breath,
which masks your stare through visor haze.
We dance on the swirls of cloud tops,
while skirting the islands of blue.
You know my heart beats fast for you.
Oh, Space is my mistress,
and when our orbits coincide,
we will once again make streaks of aurora across the sky.

By mistake I had taken a picture in the Space Station Cupola that showed the reflection of my face in all seven windows. So I set up to intentionally do this, with an artistic flare. Here is the result (click to see full-size).

Here’s a photo of Europe’s Edoardo Amaldi Automated Transfer Vehicle, about to dock with Space Station last night. Click on the picture to see it full-size.

And here’s a quick video of the approach, with thrusters firing:

The sky is not the limit for producing artistic compositions. Put a camera on a tripod, point at a dark starry sky, and hold the shutter open for about 10 minutes, and the image will show stars as circular arcs. Normally, these star trails are created as the Earth rotates on its axis, with the center being close to either Polaris, the north star, or the Southern Cross, depending on which hemisphere you are in.

I got the idea to do the same thing from Space Station; however, the physics of orbit adds a special twist. As Space Station orbits, it keeps one side always facing the Earth (the nadir direction from the crew’s point of view). This requires the Station to complete one revolution about its axis each orbit, just like the Moon. ISS rotates about its center of mass, which happens to be in the Unity, or Node 1 module. So it rotates almost aligned with the Station’s long, backbone-like truss.

Space Station makes one revolution every 90 minutes (the Moon takes 28 days). As a result, long-exposure pictures taken from the Station show star trails as circular arcs, with the center of rotation being the poles of Space Station (perpendicular to our orbital plane.) Space Station is inclined 51.6° from Earth’s equator, so the “poles” are now at 38.4°.

This picture was taken pointing to port, so it shows the end of the port truss with solar panels. Click on the images to see them larger.

My star trail images are made by taking a time exposure of about 10 to 15 minutes. However, with modern digital cameras, 30 seconds is about the longest exposure possible, due to electronic detector noise effectively snowing out the image. To achieve the longer exposures I do what many amateur astronomers do. I take multiple 30-second exposures, then “stack” them using imaging software, thus producing the longer exposure.

Due to our altitude, it is possible to see both the north and south axis of our orbit at the same time. This makes possible star trail images with two circles defined by arcs with opposite inflections. This geometry is hard to arrange from only one window, so I used a fisheye lens with a full 180° image circle to create the composition above.

In addition to the star trails, many other phenomena of nature can be seen. But I’ll save that topic for another post.

The flash of an Iridium satellite slants across the star trails.

An Ariane 5 rocket carrying Europe's ATV cargo vehicle appears as a diagonal streak in this March 23 photo.

Star trails and satellite flashes above, lightning storms below.

Tierra del Fuego, the land of fire, was what Magellan named the tip of South America in 1520. He had seen the fires set by local inhabitants who did not want the Portuguese explorer to set foot on their land.

A new page in the history of this distant part of our globe is now being written. Oil has been discovered off the eastern shore of Tierra del Fuego, and Argentina is building offshore platforms to access it. Brightly lit, they appear from orbit as constellations—not in the starry sky, but on the surface of the sea. Collectively, they are one of the most brightly-lit areas I have seen anywhere on Earth (except for Las Vegas, which still holds the title). From my orbital perspective, this is no longer Tierra del Fuego but Mar del Fuego.

In these pictures taken from Space Station, the dim lights from Tierra del Fuego, visible in the background in the first image below, do not hold a candle to the bright lights of the offshore oil platforms. Click on the images to see them larger.

Gold, silk, and spices were tangible treasures from past exploration. The Conquistadors were particularly good at extracting gold from the local inhabitants. Sir Francis Drake, before he acquired the title of “Sir,” brought back enough treasure from his circumnavigation of the globe to provide more than half the income for the British crown for an entire year. The frontiers of space likewise offer treasures won from exploration, treasures that will enrich our lives and enhance our standard of living. These treasures are golden but not gold. They contain secrets about the biochemistry of life, and will allow us to increase our understanding of how life functions. No more silver and gold; from Space Station we have blood, spit, and urine, treasures that contain secrets more valuable than a chest filled with pillaged Aztec gold.

On Space Station, we are human guinea pigs for a wide variety of medical experiments. The weightlessness of space offers a biochemical challenge to our bodies, which develop 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 these maladies, humans can thrive in space, proving that as a species, we are a hardy lot and can explore places where we were never meant to go.

The microgravity 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 possible variation of environmental parameters. She has tweaked temperatures from hot to cold, pressures from high to low, chemical compositions from reducing to oxidizing and acid to base, and more. She has thrown stones at us from space and spewed out molten rock and ash from within. The layers of rocks are littered with fossils of hapless creatures that could not make the grade, or, through no fault of their own, were simply caught in the wrong epoch of geologic time. The history of life on Earth is the story of species extinction, a fascinating thought for those of us that are still here and can contemplate such a construct.

With all this change, with all this process, throughout all the evolution, the one factor that has been constant for billions of years is the magnitude of Earth’s gravity. Now we can venture off the planet and for the first time in the history of life, vary the influence of gravity by a factor of one million. The fact that we can survive in space is in itself an amazing discovery. We truly are off in a new frontier, one that life has never seen on Earth, and it is on this frontier that physiological secrets can be pried from the people who go there.

As the crew of Space Station, we routinely puncture veins, drool on cotton swabs, and urinate in bags. 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 months before return passage to Earth can be arranged. To ensure safe passage of these treasures through the ride back to Earth, NASA has developed a special cold box that keeps them frozen for several days, ensuring unthawed recovery by ground crews, happy life science researchers, and crew members relieved to know that their bloodletting was not in vain.

The hot box in a tent in Antarctica, keeping our electronics warm.

The cold boxes themselves are an engineering marvel. They are nearly equal in thermal conductivity to a vacuum dewar (Thermos bottle) with only a fraction of the mass. They are made from truly space-aged materials; aerogel and Mylar. Aerogel is 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 a density 7,000 times greater than air) making it one of the best thermal insulators known, bested only by vacuum. Aerogel is brittle, readily crumbing into 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 a vacuum-packed bag of coffee (which feels brick-hard until the package is opened). These Mylar-packed aerogel structures can be made into odd shapes, enabling cold boxes to fit in unused pie-shaped spacecraft volumes.

When new technology is developed, other unintended uses often surface. Such was the case for the cold box. Developed for space, it ended up in Antarctica, not for keeping things cold but for keeping them warm. In 2006-2007, I had the good fortune to live in a tent about 200 miles from the South Pole during a scientific expedition to Antarctica as part of a meteorite gathering team called ANSMET (Antarctic Search for Meteorites). The conditions found in Antarctica preserve and concentrate meteorites, a discovery not realized until the early 1970’s. They accumulate on the surface of the blue glacier ice, and because they appear as strongly contrasting black specks from a distance, they can be recognized from afar and gathered like cosmic Easter eggs. For the last 30 years, annual expeditions working during the short Antarctic summers have gathered over 20,000 meteorites. During our six-week stay, we advanced this number by 850.

Our Nansen sledge differed little from those used in the 1880s. The NASA hot box is lashed to it (inside the black bag).

Living in a tent under primitive conditions, the ambient temperature danced around -20° C throughout the continuous daylight of the 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 was lit. Any water-based substance became a frozen lump. Most electronic devices refuse to operate under these conditions; from batteries that do not make sparks (lithium-ion batteries do not like to be charged if less than 0° C), LCD displays that give only blank stares, or hard drives that do not turn at the right speed.

The Antarctic hot box in its former life was an engineering test article used to make thermal measurements for the design of the spaceflight units. Having served that purpose, I found it in a dank NASA cabinet, itself in cold storage and seemingly of no further use. Brought out from retirement, this high-tech space cooler found itself strapped to a Nansen sledge, pounding through the Antarctic interior over snow structures known as sastrugi. In a sea of cold, it offered a small oasis of warmth. We also kept our Tabasco sauce and sourdough starter in the hot box, demonstrating the value of having small comforts when living on the frontier.

Thus we behold the new treasure garnered from the frontier of space. Not gold or spices, but knowledge. Knowledge always has value, even if we don’t immediately know or recognize it. The real treasure of new exploration is the larger knowledge base and the expanded imagination we develop from it. In time, all knowledge shows itself to be useful in some way. The fact that today it is difficult to pinpoint the value of space exploration shows that it is truly venturing into terra incognita, unknown territory.