If the process of getting up to space is violent and uncomfortable, the process of coming back down is even more so. Descending in the Soyuz capsule is one of the most dangerous moments of this year, and it will be one of the most physically grueling. Earth’s atmosphere is naturally resistant to objects entering from space. Moving at the high speed of orbit, any object will create friction with the air—enough friction that most objects simply burn up from the heat. This is a fact that generally works to our advantage, as it protects the planet from the many meteoroids and orbital debris that would otherwise rain down unexpectedly. And we take advantage of it when we fill visiting vehicles with trash and then set them loose to burn up in the atmosphere. But it’s also what makes a return from space so difficult and dangerous. The three of us must survive a fall through the atmosphere that will create temperatures up to three thousand degrees and up to 4 g’s of deceleration. The atmosphere seems designed to kill us, but the Soyuz capsule, and the procedures we go through, are designed to keep us alive.
The return to Earth will take about three and a half hours, with many steps we must get through successfully. After pushing away from the station, we will fire the engine to slow us slightly and ease our way into the upper layers of the atmosphere at just the right speed and angle to start our descent. If our approach is too steep, we could fall too fast and be killed by excessive heat or deceleration. If it’s too shallow, we could skip off the surface of the atmosphere like a rock thrown at a still lake, only to later enter much more steeply, likely with catastrophic consequences. Assuming our deorbit burn goes as planned, the atmosphere will do most of the work of slowing us down, while the heat shield will (we hope) keep the temperatures from killing us, the parachute will (we hope) slow our descent once we are within ten kilometers, and then the soft landing rockets will (we hope) fire to further slow our descent in the seconds before we hit the ground. Many things need to happen perfectly or we will be dead.
Sergey has already spent days stowing the cargo we will be bringing with us on the Soyuz—our small packages of personal items, water samples, blood and saliva for the human studies. We pack up some trash to be disposed of in the habitation module of the Soyuz, and I include the head of the gorilla suit, since I don’t want to be held responsible for any future Space Gorilla antics. Most of the storage space in the capsule is devoted to things we hope we never have to use: the radio, compass, machete, and cold-weather survival gear in case we land off course and must wait for the rescue forces.
Because our cardiovascular systems have not had to oppose gravity all this time, they have become weakened and we will suffer from symptoms of low blood pressure on our return to Earth. One of the things we do to counteract this is fluid loading—ingesting water and salt to try to increase our plasma volume before we return. The Russians and the Americans have different philosophies about the best fluid-loading protocols. NASA gives us a range of options that include chicken broth, a combination of salt tablets and water, and Astro-Ade, a rehydration drink developed specifically for astronauts. The Russians prefer more salt and less liquid, in part because they prefer not to use the diaper during reentry. Having figured out what worked for me on my previous flights, I stick to drinking lots of water and wearing the diaper.
I struggle into my Sokol suit, which is even harder to get into here than it was in Baikonur, where gravity kept things still and I had suit technicians to help me. We used the suits once when we relocated the Soyuz before Gennady left, and I put mine on again a few days ago for the fit check—other than that, it’s been waiting for me patiently in the habitation compartment of the Soyuz for a year. As I pull the neck ring up over my head, I try to remember the day I put this suit on for launch, a day when I’d eaten fresh food for breakfast, had taken a shower, and had gotten to see my family. I also saw a lot of other people that day, people everywhere—hundreds altogether, some of them strangers I’d never seen before and would never see again. That is the part that seems strangest now. Everything about that day seems distant to me, like a movie I saw once about someone else.
I’m preparing to climb into the capsule for the ride home, contemplating packing myself into that tiny space again. We float into the center section of the Soyuz, the descent capsule, one by one. First Misha squeezes his tall frame in, closing the hatch partially behind him in order to struggle into the left seat. Misha opens the hatch so I can float down; then I squeeze myself past the hatch, hoping that none of the hardware on my suit scratches up the hatch seal. I get into the center seat, close the hatch to get it out of the way, then awkwardly shimmy myself over to the right seat. Once I’m in, I open the hatch again, and Sergey settles himself into the center seat. We sit with our knees pressed up to our chests.
We are in the seat liners that were custom molded to fit our bodies, and they are more important now than they were on launch day. We will go from 17,500 miles per hour to a hard zero in less than thirty minutes, and the seats, along with many other parts of the Soyuz, must work as designed to keep us on the winning side of a battle against the forces of nature. We strap ourselves in as best we can using the five-point restraints, easier said than done when the straps are floating around us and any tiny force pushes us away from the seats. It’s hard to get secured very tightly, but once we are hurtling toward Earth, the full force of deceleration will crush us down into our seats, making it easier to fully tighten our straps.
A command from mission control in Moscow opens the hooks that hold the Soyuz to the ISS, and soon after, spring-force plungers nudge us away from the station. Both of these processes are so gentle that we don’t feel or hear them. We are now moving a couple of inches per second relative to the station, though still in orbit with it. Once we are a safe distance away, we use the Soyuz thrusters to push us farther from the ISS.
Now there is more waiting. We don’t talk much. This squashed position creates excruciating pain in my knees, as it always has, and it’s warm in here. A cooling fan runs to circulate air within our suits, a low comforting whirr, but it’s not enough. I remember sitting in the right-hand seat of a different Soyuz, remarking to Misha that our lives without fan noise were over. That seems so long ago. Now, I can’t remember what it’s like to be in silence, and I yearn to experience it again.
I find it hard to stay awake. I don’t know if I’m tired just from today or from the whole year. Sometimes you don’t feel how exhausting an experience has been until it’s over and you allow yourself to stop ignoring it. I look over at Sergey and Misha, and their eyes are closed. I close mine too. The sun rises; forty-five minutes later, the sun sets.