Head of the Hellenic Space Center outlines future challenges, new avenues of investigation | eKathimerini.com

Frozen moons, hot stars, the search for conditions conducive to life, exoplanets, galaxies moving apart as the universe expands, future journeys into the past of the universe, new expeditions. The amazing effort to explore the universe not only fires the imagination, but opens new avenues for scientific inquiry and for all mankind.

Celebrating World Space Week, celebrated October 4-10 each year – the dates evidenced by the launch of the first artificial satellite, Sputnik, on October 4, 1957 and the effective date of the UN Outer Space Treaty 10 October 1967 – We discussed current and future space challenges with Ioannis A. Daglis, President of the Hellenic Space Center (HSC) and Professor of Space Physics at the University of Athens.

Despite the fact that there are no “Chinese Walls” in space exploration, we have divided the scientific effort into three parts: first, those relevant to Earth, our common home; second, those pertaining to the solar system; third, the universe behind it. Travel to distant celestial bodies may excite us more, but around 90% of space exploration involves the environment around Earth.

“Space is a platform for observing our planet and developing a range of critical services that influence and facilitate our daily lives: communication, navigation, weather forecasts,” says Daglis. “The economic activity of states and companies is intense. More than 4,500 satellites are already orbiting the earth and another 2,500 are inactive. Big technological leaps have been made, but we are looking for solutions aimed at further improvements,” he adds.

To meet Greece’s needs, the Hellenic Space Center is attempting to improve the 10×10 meter resolution provided by (Copernicus) the European Earth Observation Programme. “It’s good, but not good enough for our national needs. HSC is developing a national satellite imagery program with a resolution of 3×3 meters, an improvement by a factor of 10,” says Daglis. “Also, observation satellites are in relatively low orbits, 500 to 2,000 kilometers high, to provide good spatial resolution. However, because they are constantly orbiting the Earth, they do not provide the continuous coverage of geostatic satellites, which orbit 36,000 kilometers from the surface and constantly hover over the same area of ​​our planet. Obviously, the image resolution from such a height is much lower. The space industry is trying to combine information from these two types of orbits.”

The new era, ushered in by plans for private companies to launch large fleets of satellites, will bring new challenges but also dangers, notes Daglis. “Continuous launches will put long-term stress on the space ecosystem. Overload will increase the risk of collisions between satellites, which will lead to space debris, which in turn could seriously damage or completely destroy other satellites. We have to face the problem and regulate it. It takes a long time to update global treaties on mutually beneficial use of space at the UN level. The European Space Agency (ESA) has provided a great model by requiring each proposal to create an integrated plan for completing the mission, including ‘decommissioning’ the spacecraft,” he says.

higher goals

On a second level, within the solar system, higher goals are set. “A main direction is the exploration of a semi-alien world like Mars, which is believed to be the only celestial body that can, at least theoretically, harbor humans. Of course, this is a very distant hypothesis. A second line of research targets the frozen moons of Jupiter and Saturn, which are of great interest to astrobiology as they may harbor some type of life beneath their frozen surface. This is something we cannot rule out, for example at Europa or Enceladus, since on Earth itself we have discovered life at great ocean depths in conditions that we had previously considered prohibitive,” notes Professor Daglis.

In 2023, ESA will launch its JUICE (Jupiter Icy Moons Explorer) probe, which will make detailed observations of the giant gaseous planet Jupiter and three of its four largest moons (Ganymede, Callisto and Europa), which are believed to have water beneath them have ice surface.

“Magnetic field measurements in Europe can only be explained by the rotational movement of salt water. Jets of water have been documented in Enceladus, a moon of Saturn. NASA is already considering future expeditions aimed at drilling through Europa’s ice,” explains Daglis.

Another research project in our solar system is a better understanding of the sun-earth system and the interaction of the two bodies. “We have made great progress, but we want to go further. For example, we want to predict space weather and space storms, just like we do on the surface of the earth, which will greatly benefit the safety of expeditions and satellites,” notes Daglis.

In the infinite universe beyond the solar system, the driving force of human exploration is above all the basic scientific questions about the cosmos. “Our spaceships have reached a tiny part of the universe. We were surprised how many old galaxies we discovered. The universe is much older than we thought.

We get our information from photons, from the entire spectrum of electromagnetic radiation and more recently from gravitational waves. Now we’re getting clearer images of distant celestial bodies that go way back in time. The James Webb telescope helped a lot; it was also able, for the first time, to detect the atmosphere of exoplanets, i.e. planets outside the solar system,” says Daglis.

earth to the moon

Our last question concerns mankind’s first stop in space. Why is another expedition to the moon being prepared? “First of all, we can more easily launch heavier spacecraft from the Moon to Mars or elsewhere. In addition, the moon contains valuable minerals such as rare earths. And of course it’s always exciting to walk on the moon.”