David Wolf - Letters Home
Subject: Little things mean a lot up here
Back of the envelope calculation: I've traveled roughly 17 million miles since we left the crew quarters at Cape Kennedy, not including the van ride to the pad. But who's counting. In fact, Earth seems a bit dreamlike these days, as we are connected only by crackling voices on the radio and the photographs brought along and our memories.
Today I awoke from that dream where all my friends and I are playing water volleyball in a big room. Without gravity. We watch each other try to get to the ceiling. For some reason nobody quite makes it. I awake against the ceiling of a densely packed storage area of the Krystall Module of Space Station Mir. It's the place where I have been temporarily sleeping while spacewalk activities are underway in my usual "cabin," the Kvant backup airlock. Pushed a space-shuttle-delivered water bag away from my face. Fumbled in the blackness of the night side for that spot of Velcro holding my mini-Maglite and Sony Discman. Faintly heard it still repeating "Dark Side of the Moon". Floated out of the marginally tethered sleeping bag and banged my head on the helmet of a ragged old spacesuit, long since cannibalized for parts. Cranked open the micrometeoroid cover of the heavy quartz window and, wow, there's Earth.
Hit me like the first time I ever saw it from space. Ghosty outlines of continents just illuminated by the half moon. At an unfelt five miles per second, we blow out of the Earth's shadow and into the harsh unattenuated sunlight. Solar arrays alertly take notice and rotate precisely into position to capture a bit of this fortuitous energy. We blaze over that moving line on the Earth that separates night from day. The dominant features on the planet below are two tectonic plates. One holding the Tibetan Plateau and the other, India. The plates are clearly smashing together, incidentally elevating the Great Himalayan Mountain Range. Eyes now adjusting, looking real close, there, snow covered Mt. Everest and Katmandu. It's a rare clear day over France, England, and Italy. Hazy, even smoky, into China and southern Siberia. Some large smoke plumes, a lot of forest clearing going on there. Just ahead, to the east, the incredible blue Lake Baikal, perhaps the biggest lake in the world. Set like a gem stone into the Earth's crust. "Yep, it's all still here," I think, as the heavy night of dreaming seamlessly transitions to the usual morning routine.
Pulling myself through a tightly packed passageway in the Krystall Module, I stop to retether a loose food container. Look over at the module's main control panel and note the familiar pattern of lights. All in order here. Untangle my earphone wires stubbornly hanging me up. This time in one of the power cables to a portable ventilator fan. It was necessary to set it up a few days ago to clear carbon dioxide from this temporary sleeping area. In space, without gravity-driven convection, the atmosphere is dead still. Without fans there is not enough mixing to deliver oxygen, clear CO2, or even carry the metabolic heat away from our bodies. A clanky traversal, 30 or so feet, takes me through a 3-dimensional attic swimming with spare pumps, computers, radio gear, waste containers, 800-amp batteries, oxygen candles, cables... The supplies that make this space station temporarily free from Earth's support. The warehouse of parts that, when combined with amazing human resourcefulness, have allowed this space station to operate continuously, in space, for over 11 years.
I scrape free into the central docking node. As usual, hands already too full. A flashlight, rehydratable soap, CD player, radiation monitor data disk, a bag of trash, and the opposite wall coming up fast. The docking node is the structural backbone of the station, firmly holding the six main spacecraft modules in position. Can't help but take an eerie glance at the sealed off Spektr Module hatch. Spektr's solar arrays, still tirelessly search for the Sun and send power for the rest of the station. Likely, humans will never venture back into this airless laboratory. But, the "spaghetti bowl" of functioning electrical cables, emanating from the quickly re-engineered hatch plate, stand in testimony to the result of human persistence and determination.
Morning rounds. First, I assemble our improvised water scavenging gear and squeeze in behind panel 417, in the Kvant 2 module. Wedged in between the Elektron unit and the urine reclamation system, and among a snare of wiring harnesses and tubing, one notices the constant buzz of electricity. The sound of the Elektron unit, electrolytically cracking water molecules into pure breathing oxygen and waste hydrogen. The electricity is delivered from batteries charged by our solar arrays. The water for Elektron is really evaporatively purified urine, produced by the adjacent urine reclamation system. The toilet of course, would then be directly across the aisle. Pretty efficient, huh?
Only in microgravity could one consider access to this location. Body inverted behind the panel, plying in among the systems with my gear. Here I carefully pump out the grapefruit size wobbling globes of water. They grow larger by the hour, as condensate accumulates on the ice-cold pipes supplying coolant to the power-hungry Elektron unit. A clumsy move sends water scattering in all directions. This chore generally serves as a morning shower. The "condensation" problem will be "designed out" of our next station. Next, I visit the four central air circulation intake filters and clear them of lost objects and debris of every kind. Will get to the other filters later.
Now, my favorite patient. The microgravity three-dimensional tissue cultures. Chamber 2, containing human immune system cells, has been running a tad cool. Chamber 4, growing human nerve tissue, is consuming glucose faster than planned and running on the acidic side. Microscopy of the kidney tissue is on today's schedule. It is important to observe every detail of the behavior of these cultures, as these are key preliminary studies for our tissue engineering program planned for the next space station. Today, after conferring with colleagues on Earth, we will likely change the culture media in chamber 4.
On to the protein crystal growth experiment. It is levitated and held in position by a set of electromagnets precisely controlled by a computer. In this way the ultrasensitive growing crystals are isolated from the small vibrations existing even in the spacecraft. Particularly when Anatoly is on the treadmill. In space, a "crystal" may be essentially a runny jello that would collapse under it's own weight in gravity. Or, it can be a solid material whose atoms will not sufficiently organize in the presence of gravity, to even form a crystal. Here, absence of convection helps us crystallize these medically important proteins and allows analysis of their structure and function.
The scientists on Earth are evaluating the data from last week, downloaded from the micro-accelerometers on the levitated platform. We are already far beyond what can be achieved on Earth, but their theory says we can do better. They say we just need to tweak the gains and cut-off frequencies in the digital feedback control system a bit. There is still time to change their design of the next version, for use on The International Space Station. Darn, that's what has been nagging at me. Later today I'm scheduled to review, on optical disc, their latest plan for next week's crystal growth studies. This time, using laser interferometry, we will study the crystal growth patterns on a size scale of one wavelength of laser light. Better get to the rest of the air filters. Maybe I can find that disc that I lost yesterday.
A quick look at the radiation detector data. High. Much higher than we have been seeing. Air pressure and air composition data looks good. Pasha posts the communication pass times and updates the orbital trajectory navigation programs. He checks the spacecraft electrical system current draw vs. solar array energy production and then we meet for coffee at the galley. Later Pasha is scheduled to change a coolant pump as preventative maintenance for the spacecraft's thermal control system.
Tolya, while I was still playing zero-gravity volleyball with my friends, was overhauling the spacesuits after yesterday's spacewalk. This guy is always up early. Yesterday he changed a vacuum regenerable CO2 absorption cartridge, in the Vozdukh air purification system, before breakfast. He scans the ship's master caution and warning panels. Reviews the system status displays. Then, satisfied with our gyroscopic attitude control system and conventional thruster engine status, Tolya does a double flip, that would raise Anna Corbit's eyebrows, over the dinner table and joins us, with a big smile. I poke the recycled water delivery needle through the septum of the bag of rinseless soap and fill it with warm water. Tolya rehydrates a bag of white stuff with nuts that I haven't figured out the identity of yet. We quickly trade information and check in with Earth. They tell us there's been a solar flare. Nothing to worry about but better if we sleep in the areas better protected fromradiation. So much for my move back to the airlock.
Inevitably, morning rounds generate a to-do list of maintenance that must be worked into our daily plan. Yesterday it was the air/fluid separators, which provide bubble-free water to the ion exchange purification columns. This is essential for recycling atmospheric condensate back into drinking water. The day before, a solar array wasn't tracking the Sun properly. After Monday's spacewalk, the primary airlock failed its leak check upon repressurization. The backup airlock, my bedroom, had to be used. It's too full of stuff now for me to move back into--even if the radiation level was normal.
During yesterday's spacewalk, the newly installed solar array failed to completely unfurl with the automatic computer sequence. Always something. Just like I remember my house on Earth. With each problem comes a new lesson, though. Each "failure" is really another glance into that crystal ball foretelling the "would have been" future of our joint space station, had we not this clairvoyant opportunity. But the lab goes on running. We protect the lab. First, basic life support, second, the lab, then the creature comforts like hot water, or extra lighting, or movies, music... Time to go to work.
We do pretty good most of the time. We have a busy life up here. It definitely has it's moments. Microgravity can be a very difficult, even frustrating, place to work. It can also be incredible fun. A dream come true. The work days are long but there really isn't anywhere else much to go. Little things mean a lot up here. A few casual words on the radio, a token sent on the infrequent resupply ships, e-mail. We love the candy sent by the good folks at Moscow's famous "Kracnie Octobrie - Red October" candy factory - hint, hint. Sometimes, I just like to float back, cloud of macadamia nuts surrounding me, hovering bag of rehydrated grapefruit juice, and watch a video movie. Particularly scary ones about space.
Remember the look you got from your dad the first time you got to drive alone, or your airplane instructor at your first solo flight? That was Tolya (our commander) when he and Pasha shut the hatch to go outside for their spacewalk Monday. We all know I don't drive this thing so good, but the time had arrived to hand over the keys. The rolling of their eyes gave me the distinct feeling that they really didn't even want to be there to watch. Well, we got through it. I felt like the kid in "home alone" as I assumed Tolya's usual posture at the central command post, the cockpit. Or, was it Kirk's position? Dream and reality run so close here.
Tolya is a master spacewalker and yesterday was his fourteenth EVA. Pasha on his second. With their 6-pound-per-square-inch pure oxygen pressurized gloved hands they transported and installed a massive 50-foot solar array. We all work out, every day, so we will be able to even move the fingers of these pressurized gloves during a 6-8-hour spacewalk. The hands wear out first. What a sight (and sound), two suited cosmonauts crawling around outside. Occasionally surprising me by looking in a window (brought to mind an image from one of those scary space movies). Moving hand over hand as they place each next critical tether. I study each move, as next month it is my turn to go outside with Tolya. The position of their little "one-person" spacecraft can be tracked by the clanking sounds through the ship's aluminum alloy hull. From their mobile jungle of cables, tethers, and metal boxes, sprang - well, almost sprang - a gorgeous new gallium arsenide solar panel. It kinda sprang halfway and stopped.
My job was issuing the computer commands to the new array's deployment mechanism, and something didn't work. Now we were "off nominal" and "out of the checklist," going fast, in Russian, and short of time left on the spacesuit carbon dioxide scrubbers. In coordination with the Russian mission control center, Pasha, and Tolya, we improvised manual sequence procedures to command the solar array deployment - "Retract two steps - disable motion quick, it's jammed - try to re-extend by one step - what are the motor power indications?, is there a center-section deployed indication?, we need to re-initialize the sequencer..." as fast as my fingers could press buttons. Finally, I have an answer for that repeating question, "What has been your toughest moment so far in the mission?"
Then, as the sudden blackness of the Earth's shadow envelopes the "walkers," helmet lamps blink on, and Tolya shouts, "On dviegaet (it's moving)." The team continued to work the array all the way out--to the fully deployed position using this new manual sequencing mode, developed on the spot. It was a real thrill to be part of the team. Pash and Tolya hadn't even doffed their liquid cooling garments when we did a high five that sent us all into backwards cartwheels. We had more power. And power, along with atmosphere and water, is what is really important up here. The rest comes and goes. That's life in space and it sure has it's moments.
The Space Shuttle Atlantis' hatch shut, it's docking hooks released, and it's translational thruster jets fired. I could clearly see Jim's (Wetherbee) and Mike's (Bloomfield) faces peering through the shuttle's overhead window. We waved. Mike's other hand moved, and another minus Z axis translational pulse increased our rate of separation. Another volley of bright orange rocket engines flashed against the dimly moonlit Earth, and a feeling long not felt came forward. Now I remember the place I last felt it. 10 years old, as my parents station wagon pulled away from my first summer camp in southern Indiana. Standing next to a trunk of what might be needed. The things we have to do to recapture some of those youthful feelings. That satisfying thrill that something new is going to happen, and we don't know what it is yet.
By a rough calculation, about 34 million more miles to go, plus or minus a few. But who's counting. For now it's life on this spaceship and it feels good. When the time comes it will sure be great to see all of you again on the Great Planet Earth, and then, that dream will come true too.
Dave
