With more than 250 orbital missions in 2020 and 2021, the space race seems to have been reactivated for good. And it has done so in a way that was unimaginable until recently. If decades ago only the great powers had the capacity to take ships into space, today private companies promise to be able to do tourism beyond Earth orbit in the short term.
Spending a few days in a space hotel, for example, is closer than we think. In 2027 the first of them will open its floodgates. In the Voyager, guests will be able to enjoy unique sensations and views impossible in any establishment on Earth. Also Elon Musk, owner of companies like Tesla and Twitter, and his company SpaceX are about to be able to offer travelers a suggestive route around the Moon.
At the same time that flights are increasing, the space industry faces a new challenge: ensuring that all rockets launched into space are powered by sustainable energy. And the advances to achieve this are involving large space agencies, such as NASA and the European Space Agency, together with leading private companies, some of them Spanish.
One of the most prominent initiatives to decarbonize space travel is led by an Elche company, PLD Space, which develops reusable space rockets. After launch, these rockets, which are equipped with parachutes, fall in a controlled manner, allowing them to be picked up and used again on other missions. They already have several missions scheduled: in a few months they will launch the first European private rocket into space, while in 2024 they will send satellites into space aboard the Miura 5, their first orbital rocket.
The company has gone one step further to make its trips fully sustainable. It will make this possible thanks to the use of renewable fuels in its rockets, which will be custom-designed at Repsol Technology Lab. "The roadmap we have set for ourselves is to analyze the formulations until, by 2025, we can achieve a 100% renewable fuel adapted for these engines. ”, says Dolores Cárdenas, an expert in fuel development at Technology Lab, Repsol's innovation center. And it is that "in this case we will need some special parameters so that the fuel meets the requirements that the launcher needs in its takeoff, autonomy in flight and correct operation".
Currently, space rockets use either liquid kerosene similar to that used in civil aviation, or a specific rocket fuel called RP-1. With the use of renewable fuels, a reduction in the carbon footprint that can reach 90% and even be negative will be achieved. To this end, PLD and Repsol are going to study the use of advanced biofuels in these rockets, produced from organic waste, and synthetic fuels, made with renewable hydrogen and CO₂ removed from the atmosphere.
Another example of decarbonisation of the aerospace career in Spain is the HISRU project, led by the Tekniker technology center, located in Éibar (Guipúzcoa), which has the participation of researchers from the University of Cantabria and is financed by the European Space Agency.
Its objective is to develop a system that is capable of recycling the CO₂ that is present in 95% of the composition of the atmosphere of Mars and from this action obtain fuels in situ for space missions. This system will use the gray water from the astronauts who are part of the space mission and solar energy as sources that will allow the entire process to be developed.
The collaboration between these agencies, entities and Spanish companies comes to add to the effort that other international companies are making. One such example is the New Shepard rocket, which carried Amazon founder Jeff Bezos to the edge of space in mid-July last year, using a combination of hydrogen and liquid oxygen in its engine to generate propulsion and is considered one of of the most sustainable space launch vehicles.
NASA, of course, is not far behind and one of its most advanced projects, carried out in collaboration with the United States National Renewable Energy Laboratory, focuses on obtaining oil from algae to later process it and obtain sustainable fuel for its space flights.
Years before, the Japanese Space Agency had already successfully tested the use of low-emission energies in its missions. Specifically, in 2010, the Ikaro probe made use of the solar wind during its mission to Venus. What is the solar wind? A set of particles (protons, electrons and alpha particles) that are released from the upper atmosphere of the Sun. The ship had a mesh or solar sail incorporated that, when impacting with the solar wind, produced the necessary energy to move without the need for an engine. no fuel.
Parallel to all these innovations, research continues in search of new ways to drive space rockets. One of the latest, carried out by the University of California Riverside, has developed a fuel made up of boron (a chemical element present in supernovae), nitrogen and hydride, which only emits boron oxide and water, which is also capable of to generate more energy than traditional fuels.
Space flights do not stop increasing and their growth is expected to be 6% per year. Whether it is to carry out scientific research, reach Mars or transfer travelers to a hotel in the middle of space, the sector is involved in reducing the carbon footprint. Technological advances and the joint efforts of private entities and space agencies demonstrate the commitment shared by the trips of the future: sustainability and respect for the environment.
