Karen, Fyodor and LUca are gearing up for their return to earth.
Closing the hatch of the Soyuz is like closing the the cover of a just-finished book. The sense of abandonment is surprising, until I realise that a last page is nothing more than an invitation to open the first page of a next book.
I console myself with this thought as I take off my ‘civilian’ clothes, a simple T-shirt and trousers, and put on my clothes for the journey back home.
Two special garments called Kentavr were developed in Russia for the return journey: a pair of knee-high socks and elastic shorts that wrap around the calves, buttocks and thighs to minimise the flow of blood towards the lower part of the body avoiding decreased blood flow to the head. I wear them directly on the skin. I set up a belt with electrodes around my chest that record my heartbeat, the same I had when I arrived at the International Space Station. On top of this, I wear the Camelia undergarment , a cotton bodysuit .
I slowly start to put on my Sokol space suit, the procedure is not as complex as the EMU suit used in spacewalks but just as important. Karen helps me stabilise the torso while I slip into the inner pressure-layer, then I hook up the headphone cables and the biomedical band. I take my time to seal myself in the suit, pulling every strap tight and checking each coupling carefully. Meanwhile, Fyodor has completed the initial checks of the spacecraft and the computer is switched on and ready to react to our inputs.
Once again I am the first to get to my seat, microgravity makes the task easier and I remember how hard it was to go through the same movements on ground, just six months ago .
It takes Karen just a few minutes to be ready in her right-hand seat and then it is Fyodor’s turn: when he switches the Soyuz living-module lights off it will be the last time. Following the procedures in our textbooks , Fyodor seals the inner hatch and then fastens his seatbelt. How many times have I reenacted this scene during simulation? The sense of déjà vu is lessened by the Olympic torch that is firmly fastened to the structure of the reentry capsule between myself and the commander.
The undocking sequence will start in a few hours but we are already busy with leak checks. They are identical to the redocking checks performed just a week ago and Fyodor, Karen and I sail through the procedure. Everything works perfectly, no surprises – we would not be happy if there were.
The Soyuz TMA-09M spacecraft departs from the International Space Station.
Our ground controller follows every move through telemetry and confirms our comments and repeats the timing of commands to activate the undocking sequence. It is my privilege, as flight engineer, to send the commands while Fyodor visually inspects the undocking. I start the countdown in Russian at the scheduled time and give the go-ahead for start sequence. The hum of electric motors as the Soyuz hooks are opened cannot be heard through the headphones but within a few minutes we perceive a slight movement of the aircraft. We are undocked . The Soyuz turns on its secondary engines to ensure separation. For about two orbits we will drift freely away from the station. I cannot describe the feeling I had during detachment, I am glad that I cannot see the Space Station as its contours fade until they disappear. Maybe I will never be truly ready to leave the International Space Station. Maybe I will have never really left it.
The two orbits pass with regular parameter checks and review of reentry procedures. This is Fyodor’s third Soyuz flight and he takes advantage of this quieter moment to remind us once again how to prepare for the most challenging phases.
I look out of my porthole to check spacecraft position but the clouds, mixed with the snow of the glaciers amongst the peaks that fly past beneath me seize my mind. I am overcome with the same intensity when, six months ago, my eyes gazed upon the same contrast of blue and white.
Then it is time: like hundreds of times in simulations I settle into my seat until I feel the profile along my back, tightening the seatbelts with all my strength.
Separation sequence graph. Credits: NASA
I use my gloved fingers to raise the protective cover over the buttons I will press in case of emergency – I do not want any obstructions in case I am forced to use them. While Fyodor configures his screen to send images to the Control Center, I start another countdown in Russian. The Soyuz responds perfectly , every indicator is right on schedule: a vibration verifies that the main thruster has been activated and is confirmed by a light on my screen. For a little over four minutes, the commander reads the parameters of deceleration while I compare them with previously calculated values. The difference is minimal. We all wait for the computer to calculate a speed of 128 m/s and automatic engine shutdown. Another countdown: "5 , 4, 3 , 2, 1... 1 , 2, 3..." my fingers reach for the manual override button but procedure instructs me to wait before pressing it. After three, long seconds , the engine is switched off by the computer and I relax: the separation sequence will be as planned and performed automatically. It is only a matter of minutes and the instruments on our screens show that all is going well. The three-second delay will be easily corrected during atmospheric reentry .
As scheduled, like a perfectly calibrated watch, the computer begins the separation sequence, accompanied by various alarms, lights and sounds that, after hundreds of simulations, do not surprise me but are a welcome confirmation that everything is proceeding normally. The screen formations change automatically but I have to do some checks before returning to the page about landing of the Soyuz booklet. My hands move automatically while I check that the main parachute has been selected, then I open the valves that allow ventilation after landing and close the valve that until recently let oxygen from the service module into our suits. The service module has left us to turn into a wreck as it disintegrates in the plasma that will soon surround us.
Soyuz TMA-09M seen from BA15. Notice aircraft cockpit reflection.
Credit: Simon Wijker
My last look outside from space shows that we are rotating slowly as expected. Everything out there is black. A blackness I know well. I glance at the instruments: I want to be sure to catch the entry into the atmosphere that the spacecraft calculates based on our deceleration. At the exact moment that the computer indicates reentry I turn my head in the helmet of my Sokol spacesuit to look outside: a white, dense light flashes at me through the window as if the Soyuz were sinking into a thick liquid. I begin to feel the pull of gravity. I read the data on my screen, confirming the readings read aloud by Fyodor. At just 0.5 g I feel crushed by a giant hand that makes me sink into my seat. With my right arm I change the computer screen to a different formation to read the parameters of the onboard systems and it feels as if I was lifting someone else’s arm. When I read 2 g it is difficult to breathe, my chest is crushed by the weight of my suit and my body but that is just the beginning. I make an effort to look outside again and it is worth it: the spectacle of colour waiting for me outside the porthole hypnotises me – red and orange dominate the field of view and at our supersonic speed I see the remains of our heat shield burning as it passes by like a meteorite along the direction of flight , disintegrating at 1600 degrees of white heat.
"Karen, look, look outside ...", that is all I manage say.
Credits: ESA-D. Detain
The numbers continue to flow relentlessly , 2.5 g , 3 g, 4 g, 4.5 g. Now I feel the weight of the skin on my throat crushing my larynx and when I read the peak measurement at 4.91 g, I find it hard to speak the parameters. The g forces last just a few, but long, moments. When deceleration decreases it is greeted by relief from all of us . Now we are falling through Earth's atmosphere at about 400 m/s and at regular intervals Fyodor tries radio contact, hoping to catch the signal of rescue helicopters.
Soyuz TMA-09M is seen moments before it lands southeast of the town of Zhezkazgan, Kazakhstan with the crew of Expedition 37. Credits: NASA/C.Cioffi
When the parachute opens it feels like being on a roller coaster. The spaceship is tossed from side to side while rotating on its axis at 13° per second but I feel great and I laugh from pure joy. The last events occur rapidly: on the computer screen I observe the cabin depressurisation and I know that soon the remains of the heat shield that protected us from the infernal heat of the plasma will be released. With a jerk we get rid of it, then the three, pneumatically cushioned seats are released and move towards the cockpit in preparation for the impact of landing.
The rescue helicopters communicate our altitude- 2000 meters, 1500 ... with surprising speed it is time to tighten our seat belts for the last time. "Brace for impact!". I fill my lungs with air, close my mouth, stiffen all the muscles in my neck trying to push into my seat. The impact, which coincides with the firing of the retro-thrusters, empties my lungs and reverberates through my body while our seats collapse, reducing the deceleration from about 20 g to 5 g. What remains of our Soyuz bounces a couple of times before stopping on its side. Inside, we look around, three thumbs raised in front of us to confirm that we are fine. I am laughing like a child.
I feel a strong sense of almost palindromic symmetry of what I experienced. A six-hour flight brought me to the Station in May. Six hours ago I was still on board. Now I am back. Nothing has changed – nothing will ever be the same.
NASA Flight Engineer Karen Nyberg, left, Expedition 37 Commander Fyodor Yurchikhin of Roscosmos, center holding the Olympic torch, and ESA Flight Engineer Luca Parmitano sit in chairs outside the Soyuz capsule just minutes after they landed
Credit: NASA/Carla Cioffi