by Scott Kelly
My tumultuous relationship with carbon dioxide has been going on as long as I’ve been flying in space. On my first shuttle mission, which was seven days, I was responsible for changing the lithium hydroxide canisters on board that scrubbed the CO2 from the air. I remember each time I changed the canisters, once in the morning and once at night, I would become aware soon after how fresh the air was—only then did I realize that we had been breathing bad air. Part of our training in advance of flying on the shuttle was meant to let us experience and recognize the symptoms of high CO2; we each went into a booth in the flight medicine clinic to put on a breathing mask that gave us slowly increasing levels of carbon dioxide.
On my second flight into space, again on the space shuttle, I became more aware of how CO2 was affecting me and talked with my crewmates about their symptoms. I could pinpoint those moments when the CO2 was the highest just from the way I felt. I decided to make an effort to start a more serious conversation about its effects. A new space station program manager had just been appointed, and soon after I was back on Earth I helped arrange to bring him on a visit to a Navy submarine under way in the Florida Straits. I thought the submarine environment would be a useful analogy for the space station in a number of ways, and I especially wanted my colleagues to get an up-close look at how the Navy deals with CO2. What we learned on that trip was illuminating: the Navy has their submarines turn on their air scrubbers when the CO2 concentration rises above two millimeters of mercury, even though the scrubbers are noisy and risk giving away the submarine’s location. By comparison, the international agreement on ISS says the CO2 is acceptable up to six millimeters of mercury! The submarine’s chief engineering officer explained to us that the symptoms of high CO2 posed a threat to their work, so keeping that level low was a priority. I felt that NASA should be thinking of it the same way.
When I prepared for my first flight on the ISS, I got acquainted with a new carbon dioxide removal system. The lithium hydroxide cartridges were foolproof and reliable, but that system depended on cartridges that were to be thrown away after use—not very practical, since hundreds of cartridges would be required to get through a single six-month mission. So instead we now have a device called the carbon dioxide removal assembly, or CDRA, pronounced “seedra,” and it has become the bane of my existence. There are two of them—one in the U.S. lab and one in Node 3. Each weighs about five hundred pounds and looks something like a car engine. Covered in greenish brown insulation, the Seedra is a collection of electronic boxes, sensors, heaters, valves, fans, and absorbent beds. The absorbent beds use a zeolite crystal to separate the CO2 from the air, after which the lab Seedra dumps the CO2 out into space through a vacuum valve, while the Node 3 Seedra combines oxygen drawn from the CO2 with leftover hydrogen from our oxygen-generating system in a device called Sabatier. The result is water—which we drink—and methane, which is also vented overboard.
Terry Virts and me working on the Seedra in the Japanese module of the ISS Credit 6
The Seedra is a finicky beast that requires a lot of care and feeding to keep it operating. It wasn’t until I was a month or so into my first mission aboard the space station that I started to correlate the symptoms I was feeling to specific levels of CO2. At two millimeters of mercury I feel okay, but at around three I get headaches and start to feel congested. At four, my eyes burn and I can feel the cognitive effects. If I’m trying to do something complex, I actually start to feel stupid, which is a troubling way to feel on a space station. Above four millimeters of mercury, the symptoms become unacceptable. The levels can creep up for different reasons. Sometimes the Seedra has to be shut off because the space station’s orientation isn’t allowing us to collect enough solar energy to power it. For example, when a Progress resupply spacecraft docks, the solar arrays need to be turned edge on so their surface area doesn’t get blasted by its thrusters. At other times there’s no clear reason for Seedra going on strike. Sometimes, it’s just broken.
Much of the management Seedra demands can be done from the ground, which is true for a lot of the hardware up here. Mission control can send a signal to the equipment, using the same satellites we use for email and phone calls. But at times, more serious hands-on maintenance by astronauts is required. The repair process isn’t simple. Seedra has to be powered down and allowed to cool. Then all the electrical connectors, water-cooling lines, and vacuum lines at the bottom of the rack the Seedra sits in have to be removed. All of the bolts holding it in place must be removed so it can slide out. On my previous mission, when I gave Seedra a good tug, it didn’t budge. It felt as if it were welded in place. I had to call to the ground for help, and they had no clue. Many meetings were called over the next few days at the Johnson Space Center while specialists tried to work through the problem.
In that instance, I went over all the bolts again and found one just hanging by a single thread. Problem solved. I pulled the beast out and eventually had to remove all the insulation to expose more electrical connectors, more water lines, and Hydro Flow connectors, which are notoriously tricky to mate. Working on a complex piece of hardware in space is infinitely harder than it would be on Earth, where I could put down tools and parts and they’d stay put. And there are so many complex pieces of hardware up here—NASA estimates that we spend a quarter of our time on maintenance and repairs. The hardest part of repairing the Seedra is replacing all the insulation, sort of like doing a huge 3-D puzzle with all the pieces floating. When we started it up again, it worked. Kelly 1, Seedra 0. I had no idea what it still had in store for me.
On this mission, the two Seedras have been giving us new issues to deal with. The one we use most, in Node 3, has been shutting down when its air selector valves, which are moving parts, get gummed up with zeolite and stick in the wrong position. The Seedra in the lab has an intermittent electrical short that we can’t quite pin down. Sometimes, over the course of a day, the CO2 level will slowly start to rise, especially when someone is exercising. As the day goes on, I’ll feel congested, with burning eyes and a mild headache. I’ve been using Sudafed and Afrin to fight the symptoms, but these are temporary fixes, and I will quickly develop tolerances. A few days ago, I asked Terry and Samantha how they have been feeling, and they both said they had noticed that when the CO2 was high they didn’t feel especially sharp cognitively. I’m frustrated that we can’t seem to get any urgency on this issue from the ground.
Part of my annoyance has to do with the fact that even though we have two Seedras on board, the ground allows us to run only one of them, keeping the other in reserve as a backup. We use the one in Node 3 because it works relatively consistently; only if it goes out, or if we have more than six people on board (as will happen in September), will we be authorized to use both. Our CO2 level could come down to a much more tolerable level with the flip of a switch in Houston, and yet we can’t convince them to do this. I can’t help but to sometimes suspect the second Seedra is kept shut off to avoid the hassle of maintaining it from the ground. It’s hard to work up sympathy for flight controllers who make this decision while breathing relatively clean Earth air. A level of six millimeters of mercury seems unconscionably high to me. The Russian managers claim that the CO2 should be kept high deliberately because it helps to protect the crew from harmful effects of radiation. If there is any scientific basis for this claim, I have yet to see it. And because (I suspect) the cosmonauts are docked pay for complaining, they don’t complain.
If we are going to get to Mars, we are going to need a much better way to deal with CO2. Using our current finicky system, a Mars crew would be in significant danger.
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THE LAST PLANNING CONFERENCE of the day will be held at 7:30 p.m., and dinnertime is shortly after that. As it’s a Friday, we are looking forward to sharing a group dinner in the Russian segment, as always. Misha is usually the first one ready to start the weekend, and he floats over to the U.S. side in the afternoon to make a plan.
“What time should we s
tart dinner, my brother?” he asks, his blue eyes wide and eager.
“How about eight?” I ask.
“Let’s make it seven forty-five,” he responds.
I agree.
After finishing up the DPC that evening and checking on an experiment, I give Amiko a quick call. “I’m heading over to Boondoggles,” I tell her, jokingly referring to the Russian segment as our neighborhood bar in Houston. She understands what I mean. I start gathering things to bring to Friday dinner in a big ziplock bag. I pack my own spoon and my own scissors for opening food bags. I pack foods to share, stuff from the bonus food container I brought up with me: canned trout, some irradiated Mexican meat, and a processed cheese similar to Cheez Whiz that Gennady loves. The Russians always share some tarry black caviar, for which I’ve developed a real taste, as well as some canned lobster meat. Samantha always brings good snacks, too—the Europeans have the best food.
With my goodie bag under my arm, I float into Node 1, then pass through the pressurized mating adapter (PMA-1), sort of a short, dark entryway between the U.S. and Russian segments. This entryway is not beautiful or spacious; it’s about six feet long and canted up at a steep angle. It’s quite narrow by design, and it’s made even narrower by the cargo we store there in white fabric bags. I pass through the Russian module called the FGB (funktsionalno-gruzovoy blok, functional cargo block), then into the service module. There I find Gennady and Samantha watching a movie on a laptop while Anton floats horizontally to them, finishing up an experiment on the wall. On the laptop, a young woman’s face flickers across the screen, a look of apprehension wrinkling her brow, while a man’s voice speaks sternly in Russian.
“Hey, what are you guys watching?” I ask.
“It’s Fifty Shades of Grey,” Samantha answers, “dubbed into Russian.” In English, Gennady welcomes me and thanks me for the food I’ve brought, then in Russian tries to convince Samantha that Fifty Shades is a great literary work.
“That’s ridiculous,” Samantha says, without taking her eyes off the screen. She and Gennady argue, half-jokingly, about the literary status of Fifty Shades in rapid-fire Russian as Misha emerges from the bathroom. Terry shows up with his own goodie bag and greets everyone.
Anton welcomes us. He flew MiGs in the Russian Air Force before being selected as a cosmonaut, making him one of the people I might have found myself face-to-face with in combat had geopolitics in the early 1990s played out differently. He is solid and dependable, both physically and technically. He has a goofy sense of humor and is a close talker, even for a Russian. He has a halting way of speaking English with pauses in unusual places in his sentences, but I’m sure my Russian sounds far worse. I once asked Anton what he would have done if his MiG-21 and my F-14 had been flying straight at each other on some fateful day—how would he have maneuvered his airplane to get an advantage on me? When I was training and flying as a Navy fighter pilot, these questions about MiGs and their capabilities consumed my fellow pilots and me. All we knew then was guesswork based on military intelligence. As it turns out, the same guesswork was happening on the Soviet side. From Anton and the other cosmonauts I’ve gotten the impression that they didn’t have much knowledge about our airplanes, and the training I got in dogfighting, flying against a very capable pilot in an F-16 pretending to be a MiG, was likely overkill by a wide margin. The Russian pilots are no less talented, they just had much less flight time than we did in our planes (I had more than 1,500 hours of experience in the F-14, while Anton has probably 400 hours in his MiG), presumably because their budgets were limited.
Anton and Misha acted as though Gennady were in charge as soon as he was on board, even though Anton is officially the Russian segment lead. Gennady has been, as always, awesome—things simply seem to go better when he is around, and everyone looks up to him as a natural leader. He doesn’t do anything to try to grab power, but there is something about him that makes people want to listen to him.
Misha has been great to fly with so far too. He has a true concern for other people, and when he asks me regularly how I am doing, he really wants to know. He cares about what’s going on in his friends’ lives, how they are feeling, and what he can do to help. What’s most important to him is friendship and camaraderie, and he brings esprit de corps to everything he does.
I’m often asked how well we get along with the Russians, and people never quite seem to believe me when I say there are no issues. People from our countries encounter cultural misunderstandings every day. To Russians, Americans can at first come across as naïve and weak. To Americans, Russians can seem stony and aloof, but I’ve learned this is just one layer. (I often think of a phrase I once read describing the Russian temperament as “the brotherhood of the downtrodden,” the idea that Russians are bound by their shared history of war and disaster. I thought I read it in The Master and Margarita by Mikhail Bulgakov, but I’ve never been able to find it in any translation; maybe I read it in Russian and this was my own translation.) We make an effort to learn about and respect one another’s cultures, and we have agreed to carry out this huge and challenging project together, so we work to understand and see the best in one another. The crewmates I fly with are crucial to nearly every aspect of my mission. Working with the right person can make the toughest day go well, and working with the wrong person can make the simplest task excruciatingly difficult. Depending on who is up here with me, my year in space could be needlessly perilous, fraught with conflict, or saturated with the everyday annoyance of a person you can’t quite click with and also can’t get away from. So far, I’ve been very lucky.
Once we’re all gathered around the table, Gennady clears his throat and makes a solemn face that lets us know he’s about to make a toast. The Russians are very formal about their toasts, and the first one of the evening is the most important. It’s always to honor the people present and our reason for being together.
“Rebyata,” he starts—“guys”—“can you believe we are here in space? The six of us are the only people here representing planet Earth right now, and I’m honored to be here with you. This is awesome. Let us drink to us and to our friendship.”
“To us,” the rest of us chime in, and the evening has officially begun.
It’s challenging for six people to eat together in such a small space, but we look forward to this chance to have a meal as a crew. We use Velcro and duct tape to secure our dinners, but there is always some stray item—a drink bag, a spoon, a cookie—floating away from its owner and needing to be retrieved. It becomes part of the dining experience to reach out and grab someone’s drink as it floats by your head. We listen to music while we eat, usually my playlist on the iPod I brought with me—U2, Coldplay, Bruce Springsteen. The Russians especially like Depeche Mode. Sometimes I’ll sneak in some Pink Floyd or Grateful Dead. The Russians don’t seem to mind my sixties rock, but they aren’t very interested in hip-hop even though I’ve tried multiple times to introduce them to the works of Jay Z and Eminem.
We talk about how our work has gone during the week. The Russians ask about how the Dragon capture went, and we ask them about how the next Progress resupply schedule is looking. We talk about our families and catch up on current events in our respective countries. If there is significant news involving both the United States and Russia, for instance our two countries’ involvement in Syria, we’ll touch on it lightly, but no one wants to go into any detail. Sometimes the Russians will get caught up in an American news story. For instance, when two inmates escaped from a prison in upstate New York, Gennady and Misha were fascinated with them, asking me repeatedly whether they had been captured. I would find them lingering to watch updates on CNN on our projection screen whenever they had a reason to pass through Node 1.
As the evening goes on, the Russians make their second toast, which is often about something more specific, like current events. This toast is to Dragon and the supplies it brought us. The third toast is traditionally to our wives or significant others and our famil
ies. We all stop and think of our loved ones for a moment when Anton makes this toast.
We get to talking about what it’s like to return to Earth in the Soyuz. Most of us have experienced this at least once before—Gennady has done it the most, four times—but for Terry and Samantha, their return in May will be their first time. It’s a wild ride, and the four of us who have done it share our experiences. Gennady tells a story about one of his previous Soyuz flights, when the capsule hit the ground and then rolled around quite a bit, leaving the cosmonauts with their heads below their feet. One of Gennady’s crewmates had tried to smuggle out some souvenirs in his pressure suit, and the extra cargo, along with the strange position they had landed in, left the unnamed cosmonaut with all his body weight on his groin. He was in so much distress that Gennady unstrapped himself, nearly breaking his neck when he landed on his head, in order to help reposition his crewmate and alleviate his pain. Terry and Samantha don’t look too inspired by the story.
Friday night dinners always include dessert. Russian space dessert is almost always just a can of stewed apples. We have much more variety on the U.S. segment, though our desserts aren’t gourmet level. The cherry blueberry cobbler is one of my favorites, and the chocolate pudding is always a big hit with the Russians, so I’ve brought some to share. It drives me nuts that our food specialists insist on giving us the same number of chocolate, vanilla, and butterscotch puddings, when the laws of physics dictate chocolate will disappear much faster. No one gets a vanilla craving in space (or on Earth).