With every new day, I am looking more and more forward to returning to the International Space Station – and doing somersaults while brushing my teeth again…

I am also looking forward to all the scientific research up there. The Space Station is an extremely productive laboratory: on average, the crew supervise around 300 experiments for every six-month mission, from medicine and physics to engineering and life sciences. There is no other place than in space that these experiments can be conducted. The insights that emerge from these unique experiments are immensely important for the preparation of future missions into space, but also for everyday life here on Earth. This combination makes research in orbit so valuable to each of us – and to the generations that follow us.

Installing the electromagnetic levitator. Photo: ESA / NASA

These benefits for people on Earth are clear for some experiments: for example, we cannot examine the properties of liquid metal alloys on Earth without gravity disrupting the process. As soon as we pour liquid alloys into a container on Earth, the material interacts with the container on an atomic scale. To avoid this container-interference you could let the alloy float in mid-air, but this is only possible on the International Space Station. The Electromagnetic Levitator is a special smelting furnace I installed in the Columbus module during the Blue Dot mission and it allows us to observe precisely how alloys behave. In this way, we can determine their physical properties to calculate and simulate future alloys that will be stable and lighter and can be made and used on Earth. We do not perform a full research investigation in space, but instead we close the small – but crucial – gaps in our knowledge that have been blocking us scientifically on Earth.

These types of experiments have already made possible the development of new, fuel-efficient and quieter aircraft turbine-blades made of titanium aluminide. In the Horizons mission, we are now investigating transparent materials that we can look into and observe the dynamics of their crystal formation.

We are also experimenting with tiny semiconductors that may help develop the next generation of computer chips on Earth. We measure how foams can be designed so that stable, resource-saving materials can emerge from them – on Earth foams disintegrate quickly due to gravity (like the foam in a glass of beer). We are also exploring the quantum mechanics of extremely cold accumulations of atoms called “Bose-Einstein condensates”. These condensates are not stable long enough to observe on ground: but findings from the Space Station could be instrumental in helping us develop new, revolutionary computers.

In medical research, we astronauts are often our own research subjects: studies have shown similarities between the ailments we suffer from in weightlessness to the difficulties chronically ill people live with on Earth. Our immune system is weaker and weightlessness causes astronauts to lose muscle and bone mass; even our sense of balance needs to adjust to the new environment, much like people recovering from a stroke.

Working with the Microgravity Science Glovebox. Photo: ESA / NASA

Astronauts are healthy test subjects however, allowing researchers to investigate what exactly happens to our bodies on the International Space Station at a cellular level and what we can do to stop the negative effects. For example, the Brain-DTI experiment compares MRI images of our brain structures before and after the mission. We take saliva, urine and blood samples to track changes in the immune system. In the Microgravity Science Glovebox, we inject new anti-cancer drugs into tumour cells that float weightlessly in the samples, forming spherical strutures – which is a far better simulation of cells in the human body than lying flat in a Petri dish.

It will also be crucial for astronauts to cope with the medical challenges of weightlessness regarding the limited resources that a spaceship could carry along on longer missions in space, such as to the Moon and Mars. We already recycle many resources on the International Space Station including almost all of our drinking water, nevertheless, we still need regular deliveries from Earth.

We do not yet have a life support system that is good enough to fly to Mars: closing the recycling loop completely is very hard to achieve. That is why I am particularly pleased with a new photo-bioreactor that will be installed and tested during the Horizons mission. It uses algae to treat the Station’s air supply, and is a good example of progress being made in this direction. On Earth, recycling is becoming more and more important as we need to use the limited resources we have more efficiently

With some other experiments it is hard to see at first glance what concrete benefits will come from them, but fundamental research is of utmost importance because ground-breaking insights regularly come from it – insights nobody could foresee in advance. Among the important research tasks of my mission are the small, seemingly simple experiments that I will carry out for students and schoolchildren. During the Blue Dot mission, I experimented with soap bubbles, paper airplanes and gyroscopes in weightlessness and sent films of these experiments to ground. I would like to continue building on these educational experiments in the Horizons mission. That might even be the most important thing I can bring back from my mission in space: inspiring the next generation of explorers.

I would be happy if as many boys and girls think to themselves: “What he does up there, I can do too – and if I try my best, I can probably do even more.” Children grow mentally when shown possibilities – if such a spark ignites in the astronauts, scientists, and engineers of tomorrow, I have successfully accomplished my mission.