International Day of Human Space Flight: The challenges of long-term space travel

The International Day of Human Space Flight is an opportunity to celebrate our exploration of space, marking the day Yuri Gagarin orbited the Earth and became the first human in space. Since then, progress has been made: we have been to the Moon, built an orbital laboratory, the International Space Station (ISS), and sent probes to the distant corners of the solar system. But, as we look to Mars and beyond, we are faced with a new challenge: surviving for prolonged periods in an environment without air to breathe, water to drink, or soil to plant in.

This constant free fall in near vacuum conditions forces any would-be astronaut to carefully consider every element of the ship that will become home during their time outside the safety of Earth’s atmosphere and magnetic field. As of today, a couple of hours out in space are still an adventure that takes extraordinary means to be achieved. However, a crewed journey of months, or more, implies a drastically different approach. Surviving in space, in the long term, means working out ways to overcome these challenges, and the many others prolonged human space flight pose. The Research Executive Agency has managed a number of projects that work towards that goal, many of which also have applications here on Earth. One of the key difficulties in long-term space travel is carrying the resources required to sustain the crew during journeys, and upon arrival. Air, water and food are all essential for crew survival, and the longer the journey, the more of those resources are needed. Fortunately, such challenges are addressed by a number of talented individuals who have their feet firmly planted on Earth.

EU funded Horizon 2020 projects like TIME SCALE or EDEN ISS have developed technology to grow plants and vegetables in space habitats, with the International Space Station (ISS) in mind. EDEN ISS focused on the challenge of growing food in an isolated environment and with artificial light. The project built a greenhouse in the Antarctic. Making use of vertical farming, they produced 268 kilograms of food in an area of only 12.5 square meters over a period of nine months, in artificial light, and with no soil. From there, they developed a concept for a deployable greenhouse suitable for launch on a Falcon 9 rocket. In the future, this technology could supplement food brought from Earth and provide fresh food for space-faring humans, in transit, or indeed on another planet. Meanwhile, the TIME SCALE project has developed new ways to improve the already working European Modular Cultivation System (EMCS) installed on the ISS.

While food is incredibly important, water is also essential for human survival, and so it is important to bring enough water for long journeys. Current technology allows for spacecrafts to recycle their water. However, as water is vital for any lifeform on Earth, it is also home to some uninvited guests that could pose a health risk. The Horizon 2020 project BIOWYSE developed technology to monitor and treat microbiological contamination in water and any other humid and wet surfaces inside the habitat, deactivating bacteria before they become a threat to astronauts’ health.

Dealing with radiation is also a massive challenge. On Earth, our planet’s atmosphere and magnetic field shield us from most of the harmful radiation from our sun. However, in space, or on other bodies without a magnetic field, astronauts can be exposed to radiation. The Horizon 2020 project REGOLIGHT sought to develop the technology to build structures, including habitats, on the Moon using 3D printing, and lunar soil as the primary building material. In the future, these 3D printed habitats could provide protection against radiation for astronauts and researchers living on the Moon.

All of these projects and systems pave the way to extending our time in space or on other planetary surfaces. From the first Soviet Salyut space stations in the 70s to the ISS and later on through the Lunar Gateway and even on Mars, closely controlling such life support parameters will be key to our exploration of the solar system. And yet, while these projects have as objectives to get us to space, their usefulness extends far beyond that. From recycling resources and growing food in inhospitable environments to treating and extracting water, or new building techniques, Horizon2020 space research continues to produce useful science for our survival on Earth and far beyond.