The European Space Agency is very interested in Saturn's moon Enceladus

The fresh icy crust hides a deep, mysterious ocean. Plumes of water shoot out into space through cracks in the ice. An intrepid probe collects samples and analyzes them for evidence of life. The European Space Agency set out to make this vision a reality and designed a mission to explore the ocean world around Jupiter or Saturn. But which moon should we choose? What exactly is the task supposed to do? A team of expert scientists presented their findings. The mission will follow Gus, Lisa and New Athena as the first “large-class” mission for the 2050 mission, ESA's long-term plan for space science activities.

The overarching theme, “Moons of the Giant Planets in the Solar System,” has already been selected for 2021. To translate this theme into more realistic mission concepts, ESA selected a panel of leading planetary scientists to pool their knowledge and expertise. Their job? To analyze the scientific advantages of visiting different moons of Jupiter or Saturn and to help ESA identify paths to innovative technical solutions that would make such a mission possible. As part of the 2050 Expedition recommendations, scientific priorities were set: The mission should focus on the habitability of the ocean world by exploring the connections between its interior and its environment, searching for signs of past or present life, and searching for chemistry in the ocean. The surface that makes life possible. “The mission concepts we have recommended will provide tremendous scientific returns, advance our knowledge and will be fundamental to the success of detecting biosignatures on icy moons,” says Dr. Zita Martins, an astrobiologist at the Institute of Technology, who led the team of planetary scientists.

“I am very happy to be part of this process and to have seen first-hand the first steps that could lead to ESA's exploration of the moons of giant planets. Searching for habitable conditions and signs of life in the solar system is difficult from a scientific and technological point of view, but very exciting!”

Ambitious but possible.

always. Of course, big dreams should always remain within the boundaries of what is technically possible and financially affordable. While Martin's team focused on science, engineering teams within ESA's Concurrent Design Facility (CDF) analyzed what type of mission would be realistic given the technologies expected to be developed over the next two decades. “We commissioned three CDF studies focused on promising moons: Jupiter's Europa, Saturn's Enceladus, and Saturn's Titan,” says Dr. Frederic Safa, Head of Future Missions at the European Space Agency. “The team of scientists worked closely with CDF engineers on the objectives of each study. The results helped us determine what we could do with the resources we would have in 2040.”

Results in…

By focusing on the latest science, taking into account the characteristics of each moon and planned future missions to ocean worlds such as Jupiter and Saturn, scientists identified Saturn's moon Enceladus as the most attractive target, followed by Saturn's moon Titan and Europa. From Jupiter.

No space agency has ever landed on Enceladus. However, it has enormous potential for new science, especially in the field of habitability. It is generally accepted that there are three conditions for a “habitable environment” to support life as we know it: the presence of liquid water, an energy source, and a specific set of chemical elements. Enceladus meets all three conditions. The plumes that shoot through the ice crust are rich in organic compounds, some of which are essential for life. The ocean also appears to contain a powerful source of chemical energy that can fuel living organisms. The impact of such a mission could be enormous. This would once again give Europe a unique leading role in solar system science. “Surveying signs of past or present life around Saturn has never been done before,” says ESA Science Director Professor Carol Mundell. “It will ensure ESA’s leadership in planetary science for decades to come.”

Standing on the shoulders of giants

Building on ESA's Jupiter Icy Moons Explorer (Juice) mission and the NASA/ESA/ASI Cassini-Huygens mission to visit Saturn and land on Titan, this new mission will carry next-generation instruments that will reveal unimaginable secrets of an ocean world like Enceladus. It is revealed. The European Space Agency could launch such a mission in the early 2040s using Ariane 6 and reach its destination about a decade later. Similar to Goss and Cassini-Huygens, the mission – if directed at Enceladus or Titan – could make a fascinating tour of the Saturn system, with flybys of other mysterious moons, before performing a large close-up survey of the chosen target.

To significantly advance Europe's planetary science ambitions, the team assessed that the new mission should collect a sample of the ocean world, either using a lander or by flying close to the surface to remove material emitted from erupting plumes. The mission to Enceladus will land on the moon's thin-skinned south pole to collect material ejected from the ocean, while the mission to Titan should focus on lake sediments. In either case, an on-board laboratory equipped with miniaturized and highly sensitive instruments could reveal the biochemical secrets of the collected materials.

Like Gus and Cassini-Huygens, our mission to the “moons of the solar system’s giant planets” will deploy Europe’s leading technical and industrial capabilities to address enormous challenges such as limited solar energy, widely varying temperatures and communications over enormous distances. ESA is already overcoming similar challenges with Joyce. The new mission will strengthen European competencies in several scientific and technological fields, including on-orbit assembly, operation in extreme environments, landing techniques, and new scientific instruments. All of these revolutionary technologies will have a wide range of applications, far beyond the European Space Agency's space science programme.

Space Science at the European Space Agency

The European Space Agency launches roughly one large-scale mission every decade, with current and past examples including GOSS, Rosetta, XMM-Newton and Herschel. Each of these missions was extremely challenging, requiring entirely new technologies and involving thousands of leading scientists and engineers. A strong and stable space science program ensures European excellence in science and technology; The significant societal impact generates the interdisciplinary growth that ESA has to offer its Member States. This new large-scale mission to the planets' “giant moons” is the first in a series of three missions planned for ESA's Voyage 2050 programme, which will be supplemented by a selection of medium and fast missions. Together, these elements will ensure diversity and flexibility over the next two decades and meet the ambition of the European scientific communities. “By carefully planning Voyage 2050, we are ensuring that ESA's space science program secures a forward-looking set of world-class missions for future generations,” concludes the professor. Mondale.

source: European Space Agency