Phoning Helen
I phoned my wife briefly. Afterwards a helicopter took me to Karaganda and from there it was 18 hours by plane to Houston where my family and mother were waiting for me. It was very special to see them again after half a year in space. When I landed in Houston, the world still felt different, as if a large magnet was pulling at me continuously. For the first time I could feel what gravity really feels like, as I was used to the weightlessness on the ISS. Sometimes it is scary. When I was lying still in the airplane and later in bed I felt as if I was continuously falling backwards. The feeling of being paralysed and the fact that I could not walk was also unpleasant.

Baseline data collection
If you look at photos of the landing or looked at the landing on television you might think that my mission is complete. But that is not how I experience it. I took part in research for hours on the plane and later at NASA’s crew quarters in the Johnson Space Center. I was attached to electrodes and blood pressure monitors, gave blood, urine, saliva and conducted many other tests to collect as much medical data as possible. We did this so-called baseline data collection before my mission as well. We repeat the tests now so that scientists can compare the data from before, during and after the flight. They need the data to research what half a year of weightlessness has done to my body.

During the following days and weeks this research will continue so my mission is not over. I have sessions planned that I also had done on the ISS such as Neurospat and ICV. I must give debriefings whereby I recount my experiences of  my time working above Earth. I must do reaction tests and answer many questions. In addition a large amount of time has been reserved for exercise and physiotherapy. My muscles are clearly weaker after my mission, and my coordination is terrible, so I must exercise to regain my strength.

4^th of July
Luckily my recovery is going quickly. The first days I was mainly tired and sick. But I could celebrate the 4^th of July, American Independence Day, with my family. We all enjoyed immensely a fantastic fireworks display above Clear Lake. I saw the almost-full Moon  rise very slowly, much slower than in space of course. I smelled the trees, the flowers and the smell of fresh food on my plate. It is beautiful in space and I would return if I had the chance. But here on Earth things are not so bad either…

Short tour of ISS (4:06 min.)

Full tour of ISS (70:03 min.)

The first contact I had was with the people on the science base Concordia on the South Pole. They probably have a tougher time than we do up here. It is extremely cold at -80 degrees Celsius and when it is summer in The Netherlands they live in permanent darkness. The crew cannot leave, as the fuel in their vehicles is frozen and aircraft cannot reach them. Compared to their experience I think a space mission is quite varied.

A base on the South Pole is attractive to me. It must be similar to living on another planet. It might be like living on Mars. I have a lot of respect for the people that live there. They are doing research and are away from home for long periods. We do have one thing in common: our view of the beautiful stars.

On the bottom

The people that took part in NEEMO do not have a view of the stars. NEEMO is an acronym for NASA Extreme Environment Mission Operations. It is an experiment in an underwater base off the coast of Key Largo, Florida. At around twenty metres under the sea four people lived in a metal tank -one of which was ESA astronaut Timothy Peake.

It looked enticing on video. Blue-green water and many fish swimming by. The team conducted ‘spacewalks’ under water to train for a landing on Mars or on an asteroid. They also had time to conduct less serious experiments. Timothy told me that he had taken a toy helicopter to see how it flies at three times the pressure. Good fun.

I wouldn’t mind taking part in one of these programmes, maybe I will get the chance in the future. But now I must prepare for my trip back. If everything goes as planned I will have both feet firmly on the ground by Sunday morning Dutch time…

WOOV

In my schedule the Columbus maintenance was marked as WOOV, cooling systems Water On Off Valves. Previous crew had repaired a corroded valve. I had to check if the other valves in the Temperature Control System were corroded. I had to prepare thoroughly. We want to avoid releasing chemicals so the ventilation was turned off and I had to wear gloves, safety glasses and a mask. The situation was better than expected. The valves were fine.

I also loaded new software in one of the faulty Express racks so that it can be used again. There are five Express racks in three different modules on the Space Station.  Express racks are American racks that can hold many experiments. To conclude the procedure I had to work with three laptops and many cables. I was continuously in contact with NASA’s technical specialists in Huntsville. We went through the complicated procedures without any problems.

False alarm

In between the repair work we had to deal with a number of false alarms. There are three types of alarms on board: a caution, a warning and an emergency. An emergency is the worst type as it means that something is threatening the safety of the crew, for example a hole in the ISS, a fire or ammonium leaking from the cooling system. We had to deal with cautions and warnings this time. A caution means we have to attend to an experiment or hardware or else data may be lost. A warning means that there is a problem with the station. We might have lost electricity for example, or the attitude control systems might have stopped working.

When an alarm goes off our adrenaline shoots up. The cause of an alarm is unknown and it has to be found quickly. In this case they turned out to be false alarms, caused by a problem in the warning system of the Russian segment. The Russians are working hard to fix the problem. If an alarm sounds several times without a valid reason you start to take it less seriously after a while. And that is not good for safety on board.

Many maintenance tasks are planned as are scientific experiments. I wore a ‘cardiopress’ for 24 hours which meant that two bands were attached to my fingers that measure my blood pressure continuously. I also wore a ‘holter monitor’ for 48 hours to measure my heart beat. These measurements were taken for the Integrated Cardiovascular experiment or ICV. ICV is a NASA experiment that measures astronaut’s blood pressure and heart rhythm during long stays in space.

Thin legs

After a week in space my body adapted to weightlessness. Fluids are not pulled to your legs as on Earth. That is why I have thinner legs and a larger head on photos. The amount of blood in my body also decreases due to weightlessness. I have around two litres less blood than normal. We drink lots of water and swallow salt tablets as losing so much blood on Earth could cause serious problems. Hopefully my body will retain all the fluid until I need it on my return to Earth.

I wore the cardiopress for ICV. It was quite difficult. The batteries have seen better days so I had to change them every three quarters of an hour. Sleeping was difficult as I hear and feel the blood pressure bands pump and let out air as well as the batteries bleeping for attention. In addition I cannot use my left hand very well: if it hits something the measurements go haywire and the machine gets confused. Despite these small uncomfortable moments I think it is important to take part in these experiments. As a doctor I am interested in the results and it helps scientists on Earth to know how the human body adapts to space.

Orange

In between my tasks I heard from ground control the news on the European Championship football. Or to be precise: how the Dutch team has done. I would have loved to land on Earth on the day that The Netherlands played in the finals. Unfortunately this was not to be this time. Maybe I will be able to enjoy a championship final in two years’ time when I will be able to watch the match with gravity again.

In brief: scientists are looking for a shield to protect astronauts during a long stay in space. The sun and other sources continuously send radiation into space. Some radiation such as radio waves are not harmful to humans. But particle radiation or ionising radiation with higher energies can be dangerous. Especially, if you are exposed to this type of radiation for a long time. NASA has even set a limit to how much accumulated radiation an astronaut can receive. If an astronaut gets near the limit, they are not allowed to fly another mission in space.

Bulletproof vest

The solution is not to keep people Earth-bound. In the long run we want to live for longer periods in space and travel further, to the Moon and to Mars. So it is better to develop an effective shield that stops the radiation as much as possible. On Earth this shield is our atmosphere. Condensation in the atmosphere absorbs almost all dangerous radiation, so we do not suffer from it in our daily lives. On the International Space Station we do not have an atmosphere to protect us. The Altea Shield experiment will test different types of shields.

The procedures were complex. I had to hang large radiation sensors in the Station and connect them with cables. The cables float every which way: it looked like an Anaconda snake swimming around me. Altea Shield has six detectors that measure the radiation. For 40 to 60 days they will continuously measure space radiation that passes through the ISS and so reaches our bodies. On top of the detectors are walls made of polyethylene and kevlar, the same material that is used to make bulletproof vests. After testing we will know which material is better at keeping radiation away.

Protection
The search for the best space shield will continue in the coming years. Hanging water bags on the walls of space stations would be an obvious solution. Our atmosphere on Earth has taught us that water protects us against radiation very well. But water is heavy and expensive to launch in space. Once in space all that weight – as well as the weight of the ISS – must periodically be boosted so that the Space Station keeps its orbit. We are looking for a lighter material that can do the same job: protect people from space radiation. To be continued...

Return
Taking pictures from the Japanese module will also be difficult during the following weeks. We are plagued by the beta-angle. This refers to the position of the Sun towards the ISS. The beta-angle is important for generating electricity from solar panels. The windows in the Japanese modules have to be covered for the time being, otherwise sunlight would shine on hardware that would overheat. We have to consider so many things in space.
I can tell that my return flight is near from the emails I receive. Many emails refer to medical tests and my recovery on Earth as well as debriefings. ESA colleagues and other space agencies can improve procedures and prepare future space missions on the basis of my feedback. My flight is just a small part of a larger whole: humankind learning to live in space and to explore and use it for our benefit. I am pleased to be a part of this endeavour. My post-flight tour is also being organised. I will visit many places in The Netherlands and Europe with the rest of the crew to tell people about my mission.

Action
Before I can go home, every day I must run on the treadmill T2 and train hard on ARED , the Advanced Resistive Exercise Device. ARED is a fitness device that trains almost all my muscles but especially the ones in my legs and back. The exercises also increase my bone mass. I no longer need to work out on the exercise bike. My fitness instructor on Earth said: “When you climb out of the Soyuz you need to walk away and not ride a bicycle.” I do not mind running on T2 or training with ARED. I can watch science fiction films and listen to music. I saw all three Terminator films again and Starship Troopers. I watch action films as it helps me run. During weight training I listen to music: heavy rhythms such as rock and trance, dance or techno.

Radiation
In addition to these tasks I do a lot of maintenance and routine work on ISS hardware. For example I measured sound levels, took samples of water and air and checked if bacteria were growing in near ventilation ducts, towel racks and so on. The samples were returned to Earth with the Dragon. Teams on Earth will interpret the findings and change procedures. I also hung up 23 new radiation sensors. The previous ones will return in my Soyuz. The sensors measure how much radioactivity from space reaches the interior of the Space Station.  We are not protected by Earth’s atmosphere in the ISS. People should not be exposed to too much radiation so it is important to know which areas let radiation through.

These operational tasks are very fun as I have to float around the Space Station to retrieve and install equipment. One of these days I will record a film of my travels. I hope by watching the film you can imagine yourself floating around the Space Station… 

Commercial

SpaceX, an American, commercial company builds the Dragons. Think about what this means. A private company will assist spaceflight and no longer only government agencies. Soon tourists will buy tickets to sleep in a space hotel. Sounds like science fiction? I saw a glimpse of the future here in space. These times are coming! Of course we must work together to ensure that spaceflight will be safe and that the environment does not suffer… Inside Dragon it was quiet, well lit and roomy. White and blue led lights cast a glow on the equipment racks. Clearly a different style compared with the current modules on the ISS, especially compared to the Russian segment that looks as if it was from the seventies era. Dragon uses lots of plastic and less metal. It has a beautiful golden hatch. The ship reminded me of a science fiction film. Maybe because it is built in Los Angeles…

Tour…

One of the things I wanted to do during my mission was take pictures of the Space Station interior. I will start with a tour of the Russian part of the Space Station. Here are the photos:

I flew with Gennady Padalka in 2004. As this is his fourth long spaceflight he felt at home straight away and is very cheerful. It is Sergei’s first time in space however. He looks around a lot and is absorbing the new experience while moving around calmly. Joe was eager to learn immediately. Don and I have to introduce him to the Space Station. For example, he watches when I exercise on the bicycle. He also watches when we do maintenance work such as moving sensors that measure radioactivity or working with scientific racks. I feel like a veteran sometimes. Almost five months ago I received the same introduction from Dan Burbank. Now I am the one that is passing on the knowledge and explaining how everything works. Then it will be Joe’s turn to make the ISS his home. Each crew member has their own way of making themselves comfortable.

Don, Anatoly and I are the ‘bald crew’. The new Expedition members have told us that they will not cut their hair during their mission. That makes them the ‘hairy crew’. New arrivals always make mistakes using the toilet or when washing. Sometimes one forgets to turn on the suction or to brace themselves. Luckily we all laugh when it happens. We have all done it once…

Reaction times
Last weekend, just as every weekend, I did a ‘reaction self-test’. This is a test on a computer that measures reaction times. A blue block is displayed on the screen. A clock appears that measures milliseconds. When the clock appears you have to press the spacebar as quickly as possible. You never know when the clock will appear. By measuring my reaction time scientists on Earth can record how ‘alert’ I am. This differs greatly. Sometimes I must measure my times in the evening, sometimes when I wake up. Sometimes I am very busy and my thoughts go to an experiment that I am conducting. A noticeably longer reaction time is the result.

I am trying to create as many pleasurable moments as I can during the last weeks of my mission. It is amazing how time flies up here. I have only managed to fully enjoy the view from the Cupola observatory a couple of times. I leave my camera and float in the Cupola so that Earth is below me and next to me instead of above me. It is very special. I recently saw the whole of Europe in one go, simply by looking around, from Ireland to Cairo and from Norway to Morocco. These moments are magical. They will probably be the most memorable moments of my mission…