From Adlershof into the depths of the solar system
Perpective by Ulrich Köhler, planetary geologist at the DLR Institute of Space Research
This announcement in November 2025 sent a thrill through many people in this country: Europe would soon be sending three astronauts to the Moon as part of NASA’s Artemis programme—among them, for the first time, a German citizen.
This is far more than a matter of prestige. The Moon plays a central role in the exploration of the solar system, with its eight planets, more than 200 moons, and millions of small bodies that include asteroids and comets. It is a window into the past of our 4.5-billion-year-old planetary system and therefore a key to understanding Earth and the other planets. With the Moon’s near-perfect vacuum, it could also serve as a laboratory for a wide range of research fields. It also harbours resources such as water ice in deep craters at the poles. With a distance of a 400,000 kilometres, it lies virtually at our doorstep—child’s play, by spaceflight standards.
These prospects are also stirring excitement at the Institute of Space Research at the German Aerospace Center (DLR) here in Adlershof. After all, successful landings and surface operations on the Moon require detailed reconnaissance to ensure mission success. This is carried out with robotic probes—increasingly also by commercial providers capable of delivering scientific payloads to the Moon at comparatively low cost. The Berlin-based DLR institute is part of this effort. Yet the biggest scientific questions lie much farther afield—in the depths of the solar system.
The number of questions is never-ending. But distilled to their essence, they revolve around this: Why did the Earth—the only planet known to host life—develop as it did, while its similarly sized neighbour Venus veered off in a completely different direction? Is Earth’s “habitability” unique? Or might life once have existed on Mars? Could it still be home to microorganisms today—hidden beneath the surface? More exotic still is the idea that conditions suitable for life might exist beneath the icy crusts of some of Jupiter’s or Saturn’s moons. This cannot be ruled out!
All of this demands investigation. Modern spaceflight enables instruments and experiments to operate throughout the solar system, where answers to these questions may be found. DLR develops and builds—often in cooperation with industry—unique instruments that are currently en route on missions of the European Space Agency (ESA), NASA or their Japanese counterpart JAXA—to Mercury and to Jupiter’s moon Ganymede. Others will turn their attention to Venus in the coming years, to orbiting Mars, or to making a rover equipped with a Berlin-built camera touch down on its surface, likely more sooner than later. The Adlershof-based institute is also investigating how to avert the danger of a collision between Earth and a near-Earth asteroid.
The “largest” undertaking for planetary research—at least in terms of hardware—is scheduled for launch in 2026 aboard an Ariane 6 rocket: ESA’s PLATO space telescope. From a fixed observation point more than one million kilometres from Earth, its 26 individual telescopes will simultaneously observe more than 200,000 stars in the Milky Way. It is an entirely new concept—and DLR ha taken on the scientific lead. Targets of the search are Sun-like stars and planets that orbit them in the same way the Earth orbits our Sun. To be sure, these are the big questions that spaceflight is now able to tackle. Are we alone?
Ulrich Köhler for Adlershof Journal