Topical Teams

Following the detection of gravitational waves and considering the wealth of astronomical instrumentation across the electromagnetic spectrum, the radio frequency range below ~30 MHz remains the last virtually unexplored frequency domain.

The Earth’s atmosphere reflects all radiation from space below its ionospheric plasma frequency (around 20 MHz), and the turbulent ionosphere gives rise to “radio seeing”, making ground-based radio observations of the sky more difficult at frequencies below ~100 MHz but certainly prohibiting observations at the lowest frequencies. An additional complication at lower radio frequencies is that strong man-made Radio Frequency Interference (RFI) levels close to Earth require either locations which provide partial or complete obscuration of the Earth, or locations that are sufficiently remote so that the RFI levels are significantly attenuated. The lunar far side (and north and south poles) provide unique environments that can meet these requirements to open up the last, virtually unexplored, window on the universe.

The Topical Team provides a forum for the lunar community and astronomical science experts across Europe that can provide invaluable knowledge and insight that can help to inform ESA’s science preparations and advancements of lunar exploration concept studies.

Space Analog research has increased over the last few years with new analogs appearing every year. Research in this field is particularly important for future real mission planning, selection, and training of astronauts.

The purpose of this Topical Team is to perform a systematic review and make a classification of current and emerging analogs, their defining characteristics, commonalities, and what aspects of human performance can be studied in each one of them. For example:

• Cognitive, emotional, and psychosocial
• Exercise and physical activity
• Operational, including flight planning and maintaining operational capabilities under confined/ isolated conditions, robotic interaction, and virtual systems

NASA has established the world leading space biology facility for generating, processing, and storing –omic datasets for space biology. This facility is called GeneLab.

The purposes of this Topical Team are to support ESA member state scientists participating in GeneLab and to study and implement future GeneLab based activities for ESA member state scientists. Examples of current activities include bi-lateral cooperation on future space biology experiments, co-authorship on original research, and bi-lateral exploration of incorporating human biology datasets into GeneLab. Examples of potential future activities include establishing physical or virtual ESA supported GeneLab infrastructure, incorporating GeneLab based experiments in new launch/operational platforms, and partnering ESA ground and space based human biology experiments with GeneLab.

The current space programmes related to Deep Space Gateway (DSG) and the moon base require definition of programmes and of payloads and facilities for space radiation research. The radiation environment on the moon is indeed substantially different than in Low Earth Orbit (LEO). The moon has an exceedingly small atmosphere density and magnetic field intensity and is therefore much more exposed to energetic heavy ions from the galactic cosmic radiation than LEO. This increases the uncertainty on the radiation-induced late effects. Moreover, the risk of acute effects from intense SPE (Solar Particle Events) (radiation exposure from Solar Particle Events) during EVA (Extra Vehicular Activity) becomes significant and needs to be addressed. Finally, the possibility of exploiting in situ resources for thick shielding of the Moon bases is also an issue not relevant for LEO.

This Topical Team shall review the differences in the space environment between moon and LEO, and define a roadmap for scientific activities on ground, on the DSG, and on the moon for monitoring and mitigate the impact of space radiation exposure.

Synthetic biology is the design and construction of new biological parts, devices, and systems, and the re-design of existing, natural biological systems for useful purposes (Nature.com). Synthetic Biology has the potential to significantly improve the safety, stability, and feasibility of missions in space, mainly in deep space.

The 2 main goals of this Topical Team are to find ways of overcoming the principal bottlenecks of deep space exploration by recommending the development of new biological devices that identify countermeasures to protect and support life of humans during the way and to find resources for space colonization.

During space flight human physiology and health is affected by complex environmental challenges which might be most pronounced by extended periods during interplanetary missions. Adequate immune response is crucial to maintain health and is based on the interaction of lymphoid cells, inflammatory cells, and hematopoietic cells. To our knowledge the influence of stressful conditions of psychological or physical nature can activate and/or paralyse humans’ innate or specific immunity. Previous findings from terrestrial studies as well as from pre- and post-space flight studies and first preliminary data from the ISS indicate a strong interaction between stress-associated neuroendocrine mediators and the immune system. Moreover, this complex communication among immune cells is also mediated by tissue hormones e.g., derived from the cells metabolism (e.g., adenosine) and other hormone-like substances (endocannabinoids), altogether modulating the reactivity of immune cells.

The goal of this proposed Topical Team is to identify interdisciplinary approaches to analyse the impact of important variables and living conditions occurring in space or in future lunar habitats (e.g., confinement, weightlessness, different level of oxygen tension, radiation effects) and their interaction with the immune system.

Recently a diagnosis of deep venous thrombosis (DVT) was made during a long duration ISS mission, which may lead to a potentially fatal pulmonary embolism (PE). While DVTs (Deep Venous Thrombosis) can occur without PEs (Pulmonary Embolism), the latter is almost always preceded by a DVT.

This Topical Team will focus on creating an expert Topical Team in the domains of venous system status, haemodynamics, coagulation physiology, cerebral spinal fluid (CSF) dynamics and the constraints of spaceflight to define a (operationally focused) research and technological/procedural evaluation roadmap. This is to define Venous Thrombo-Embolisms (VTE) pathophysiology, clinical presentation and facilitate the assessment of risk, whilst proposing evaluation of candidate diagnostic, mitigation, and management strategies compatible with human spaceflight.

Over the last two decades, remote sensing data (and more recent surface missions) have revealed a far more complex evolution and a richer record of lunar geological processes than had been known at the start of the 2000s. There are numerous outstanding questions relating to understanding lunar mantle evolution, how the lunar primary crust was formed and early planetary formation processes (e.g., differentiation), all of which can be addressed through geological exploration of the Moon. In preparing for future lunar exploration, geological exploration can also benefit from high mobility, include dating and sampling diverse rocks and geological units, constraining the lateral and stratigraphic relationship among different units, attaining accurate geological mapping, and assessing the properties and potential exploitability for in situ resource utilisation (ISRU).

Future lunar missions will provide unique opportunities to solve lunar mysteries by innovative concepts and deploying advanced payload combinations at new landing locations, which can be informed by inputs from this diverse knowledgeable European team representing a forum for the lunar science and exploration community.

Future lunar exploration missions will target regions that hold significant potential for scientific discovery and In Situ Research Utilization (ISRU). Among these targets are partially collapsed lava tubes (pits), volcanic rilles, vents, and fresh impact craters. Various of those targets are approachable on the Aristarchus plateau, a site with a uniquely rich geology. However, many relevant outcrops and sampling sites across the plateau are extremely difficult – or impossible – to reach with traditional, wheel-based robots due to the rough surface, terrain relief, slopes >25°, or generally uncertain soil properties. On Earth, a new generation of versatile legged/wheel-legged robots has recently demonstrated its ability to navigate such challenging terrain, climbing over obstacles and traversing steep inclines, effectively unlocking regions unreachable by traditional, wheeled robots.

The Topical Team is composed of a cross-disciplinary representation of the lunar community with a strong interest in mobility solutions as part of addressing key lunar science exploration goals in difficult to reach and rugged terrain areas, which can greatly help to inform ESA’s science preparations and advancements of concept studies.

This Topical Team will examine current scientific evidence on the potential for rearing insects in space for consumption by astronauts and settlers, and evaluate:

• insect species with the right nutrient profile and food safety parameters
• impacts of space-specific environmental factors (e.g., radiation, μG) on insect physiology, rearing and nutrient profiles, and
• objective indicators to assess insect-based foods’ suitability for consumption or undesired changes that affect palatability and safety (based on interactions between the above)

Geophysical investigations of the surfaces of the planets and moons addresses important outstanding scientific and exploration questions. By learning more about the formation and evolution of any one Solar System planetary body, we learn more about how the Solar System formed as a whole and then evolved, and hence indirectly learn about the development history of all planets in the Solar system, including Earth. In addition to the science topics, geophysical investigations can identify and quantify resources (such as water and ice) that are useful for in situ resource utilization by astronauts, localize active gas-release vents (e.g., by radon monitoring), quantify the properties of near surface regolith materials for habitat construction, determine the extent of subsurface lava tubes that could become habitat locations, and evaluate potential tectonic, impact, and space weather hazards that could affect crewed missions on the surface.

This Topical Team provides a forum for the lunar community and geophysics experts across Europe to identify and constrain the major science questions and objectives for lunar geophysical exploration, which can help to inform ESA’s science preparations and advancements of concept studies.

The Lunar BioMission Topical Team is comprised of a multidisciplinary group of biological scientists in the frame of lunar surface biosciences. The team will be capable of delivering inputs to future experiments on the lunar surface, with the first being a concept study for a multi-use biology facility on Argonaut.

The lunar regolith must be mined without losing valuable resource (e.g., water sublimation) and beneficiated to remove unwanted or waste material, increase the desired material concentration and to produce a consistent feedstock for further physical and chemical processing that will recover and purify the resource. The processing methods determine the required feedstock properties. This requires an integrated design for the mining, beneficiation and processing value chain, which may allow efficiencies to be made by combining, for example, in-situ extraction instead of mining and beneficiation.

This Topical Team explores all these options by combining expertise in terrestrial mining and mineral processing with lunar materials and resource extraction scientists that are able to collaboratively conceptualise the cross-boundary implications. This is a new approach to ISRU process design.

The team outlines the main open scientific questions regarding planetary caves and refine the key science and exploration goals and mission objectives. Focus will be on developing a structured and scientifically relevant approach to cave exploration on the Moon, in line with future activities and opportunities. This approach will then be transferred to a Martian scenario, defining specific planetary cave exploration and astrobiology goals. The overall objective is to foster a strong network on planetary caves in Europe and within ESA, supporting the development of future missions to these extremely interesting environments. Planetary cave exploration could open unexpected, exciting scenarios also for human exploration in the near future.

The aim of this Topical Team is to bring together Experts on the fields of propellant management and fundamental physics to increase the European cooperation of research groups.

This Topical Team shall identify the critical physical phenomena affecting the propellant behaviour in tanks and define how to approach them to support a step forward in the state-of-art knowledge on propellant management. The definition of generic experiments isolating each physical phenomenon will be carried out with the intent of defining and validating exceptionally reliable physical models and support their integration within computational fluid dynamics programs. Finally, a more complex sloshing experiment featuring the interaction of the selected phenomena will be proposed.

The aim of this Topical Team is to develop European and Canadian research collaboration on dust combustion:

* Construction of ground -based dust burners,

* Development of optical flam diagnostic specifically designed for dust environments,

* Analysis and planning of parabolic flight experiments,

* Support of sounding rocket activities,

* Improvement and validation of models predicting fundamental flame parameters.

This Topical Team supports the exploitation of the ACES mission for fundamental physics tests by assisting both during the preparation phase and after the ACES launch in coordination with the ACES Project Scientist and the ACES science team members. More generally, this Topical Team shall address space tests of the Einstein’s Equivalence Principle based on precision measurements: both atomic sensors (atomic clocks, matter wave interferometers, etc.) and classical instruments (acceleration sensing, laser ranging, etc.).

The exact knowledge of the thermophysical properties of metallic melts in the stable and undercooled state is crucial in optimising casting and solidification processes for engineering components fabricated on Earth. While the ground-based containerless levitation techniques (ESL, EML (Electromagnetic Levitator)) in general have serious limitations for precise thermophysical property measurements, the joint research project between ESA and the Chinese Space Agency will expand such measurements further to Low Earth Orbit and make high-precision measurements feasible for a new class of materials, namely bulk metallic glasses and its composites which exhibit exceptionally low evaporation rates in their liquid state. This Topical Team is established to support the European scientists involved in this collaborative effort.

Interests of this Topical Team is in space science (like the handling of granular materials in space exploration or mining, powder propellants of rockets, planetary ring dynamics) and to study rheology, flow, and dynamics of granular media in low gravity.

This International Topical Team supports the collaboration between scientists from Europe, USA, Russia, and China on two-phase heat transfer research. It is related to ESA experiments like Multi-Scale Boiling and Heat Transfer Host experiments.

Despite decades of human space missions, there are known unknowns regarding pharmacological countermeasures (PCMs) that have not yet been satisfactorily resolved, many of which are centred on the potential effects of spaceflight-altered physiology on the handling and action of administered medications. This is also a key point of crosslinking with most of the other disciplines. Other issues centre on the medication supply since re-supply opportunities will be limited as distance from Earth increases. Current PCMs must be re-evaluated, both for suitability in new mission scenarios and updated as new terrestrial therapies are developed. Additionally, new hazards, like exposure to planetary dust, will necessitate new countermeasures.

The multidisciplinary Topical Team will investigate:

• Effects of space-altered physiology on pharmacokinetics, pharmacodynamics, drug interaction, drug-nutrition interaction, drug-microbiota interactions, and drug physical therapies interaction issues
• Mitigating medication-related problems in relation to medication use, medication supply and long-acting/personalized dosage forms
• Coping with emerging hazards such as deep space radiation, planetary hazards, and newly recognized risks to humans in space
• Optimization of existing pharmacological countermeasures via personalized medicine options, such as pharmacogenomics and update treatments used in space as per new terrestrial treatments, also solve regulatory issues on medication in space

Each astronaut is unique and predisposition to physiological changes during spaceflight and response to medicines, both efficacy and toxicity, are dependent on a combination of factors including environment and genetics. Personalised medicine aims to move away from a ‘one-size fits all’ approach to one which uses innovative approaches, such as –omics technologies, to be able to determine individual benefit-risk of drug treatment to ensure the most effective interventions or countermeasures to improve health.

The aims of this Topical Team are to explore how personalised medicine approaches can optimise astronaut drug safety and efficacy and identify risk factors that predispose astronauts to negative effects of space exploration. The medications that are currently available on the ISS are commonly used drugs that have been on the market for a long time. However, in modern medicine, even more effective medicines may be available in terrestrial practice. This Topical Team shall focus on the development of a “future space exploration package” implementing Personalized Medicine for astronauts with the aims to ensure optimal drug treatment in future space exploration journeys and gather scientific evidence on specific gene-space-conditions-interactions that may characterize an astronaut specific benefit-risk profile for drug treatment in space medicine. Identification of personalized susceptibility factors for negative effects of space exploration will enable bespoke countermeasures maximizing astronaut safety and mission success.

Disability on Earth depends on the condition and the environment. The ESA parastronaut project challenges us to re-think the environment and poses a key research question:

• What are the physiological concerns for a parastronaut before, during and after space flight?

The Topical Team shall:

• Review the literature to highlight risks and benefits of parastronaut’s missions, and evaluate procedures and technologies that could support parastronauts.

• Consider adaptations, countermeasures, and recovery in relation to space flight, as well as training and performance during routine and emergency procedures

• Focus on the physical disabilities that more commonly affect those under 60 years of age

• Identify the physiological mechanisms and limitations for safe space exploration, propose viable solutions and alternative approaches

• Provide new physiological indications for up-to-date guidelines for safe and successful parastronaut missions

• Highlight those disabilities that may be more suited to space flight

In nature, various species can physically make themselves more resilient toward such stresses in nature´s challenging conditions, from the seasonal low temperatures and the lack of food, or the geographic heat and the lack of water. This adaptation is called torpor and it is extremely attractive to be induced in a controlled manner, also in so-called non-hibernators as we humans are, because of its potentially wide use in medicine or for humans on a long-duration human space missions to Mars and beyond. The reduction of an astronauts´ metabolism by torpor would become a key advancement and a game changer for human space exploration since water and food intake could be reduced by up to 75%, thus reducing the spacecraft required payload.

The aim of this Topical Team is to review the current state-of-the-art in the hibernation and torpor line of research and to provide recommendations to ESA on this topic and the future line of research.

The main purpose of this Topical Team is to conduct a systematic literature review on dental health of astronauts during their short- and long-term crewed missions in space with critical analy is on every aspect of dental health. This review should allow formulating preliminary conclusions to be used as recommendations for guidelines to prevent dental problems that can be hard to address and solve in space and that could be one main cause of evacuation. This work will be a comprehensive investigation of dental health, which will include preventive dentistry, periodontology, oral microbiome and oral pathology, restorative, and prosthetic dentistry, TMJ (Temporomandibular Joint) and all other surrounding structures.

Bone cell response should be accurately investigated to attain a more in-depth comprehension of those mechanisms that elicit an altered pathway responsible for a general pathological outcome. A greater understanding can then support the development of effective countermeasures to be usefully integrated in future “healthcare” programs for astronauts and Earth patients, as well. In addition, the potential to regenerate bone, according to tissue engineering principles, needs to be critically considered to develop biomimetic functional biological substitutes. This expectation can also be enhanced by exploiting calcium-phosphates and graphene as “active” means to support specific cell processes, with reference to bone tissue.

To this aim, a detailed analysis of biological assays reported to date and the definition of specific protocols for in vitro cell cultures performed using ad hoc approaches, intelligently designed for space missions, will be the main topics to be considered. Addressing those issues affecting astronauts will pave the way to tailored scientific protocols and investigational analysis for safe long-term/ long-distance missions.

The plans to establish a cis-lunar station or a Lunar or Mars surface base will entail long-term stays by humans in an isolated environment which has to fulfil the needs for survival but also provide comfort for healthy living and working. A life support system including air revitalization, water recycling, food supply and waste management is therefore mandatory for human habitation in space.

The aim of this Topical Team is to identify the knowledge-gaps concerning microbial bioprocesses and bioreactors operation under space conditions to enable successful deployment in space. The final goal would be to define the general scientific and technical requirements as well as a preliminary concept or options of a bioreactor facility or station that can address the needs of several bioprocesses.

Biofilms are sessile communities of microorganisms, embedded in a self-produced matrix of polymeric substances, that grow commonly on solid surfaces. Biofilms have many implications in different fields, including bioremediation, water and wastewater treatment, air-conditioning, industrial biofouling, and medical implants contamination. In American/Russian space vehicles and the International Space Station (ISS), biofilms have been blamed for fouling of equipment, such as spacesuits, thermal control systems and air conditioning units. Moreover, the presence of biofilms in spaceflight is also related to issues like pitting corrosion of hardware, deterioration of drinking water quality, food-cross-contamination, and human diseases. Although the necessity to study biofilms formation in microgravity conditions is essential, efforts so far have been sparse and scattered.

The aim of this Topical Team is to concert activities among research teams for the systematic investigation of biofilm formation in microgravity conditions. The strength of this Topical Team is that it can assess biofilms using approaches and perspectives from various scientific disciplines taking advantage of the complementary expertise of different research teams. Emphasis is given not only to understand biofilm formation but also identify suitable means and procedures for biofilm prevention and cleaning of contaminated surfaces. Microorganisms and substrates representative of space and terrestrial applications will be selected and a research plan addressing critical scientific problems will be defined together with relevant participating industries.

As bioprinting is evolving rapidly in the moment and frequently novel methods as well as materials are coming up, task of the proposed Topical Team is to investigate state-of-the-art and newest developments with respect to their possible applicability in exploratory missions and extra-terrestrial human settlements.

Atmospheric Physics, Physics of the Upper atmosphere, coordination of science related to the ASIM mission:

1. High-energy thunderstorm processes
   • How are photons created with energies up to 100 MeV?
   • What is the proficiency of thunderstorm discharges in creating antimatter?
   • What makes thunderstorms discharge in gigantic lightning flashes reaching the ionosphere?
2. Atmospheric science
   • How do thunderstorms affect the stratosphere and thereby the climate?
   • Can we predict severe storm intensification from lightning activity?
   • To what extent is thunderstorm electrical activity affected by dust particles? Atmosphere-space interactions
   • Quantify energetic particle precipitation and its relation to auroral and to solar conditions
   • Origin of meteors
   • How large is the thunderstorm source of high-energy electrons in the mesosphere?

This international Topical Team promotes and establishes the field of solidification of containerless undercooled melts. It comprises specialists in the field of solidification both from an experimental and a theoretical side that are qualified by outstanding scientific work on solidification with the focus on application of containerless processing of melts of metals and semiconductors both under Terrestrial and Space conditions. Although scientifically well established, the significance of non-equilibrium solidification from undercooled melts and the related physical mechanisms such as crystal nucleation, growth modes and their dynamics is scarcely noticed in industrial research. Accordingly, the team elaborates experiments related to the topic, with respect to industrial needs.

The overall objective is to enhance the fire safety in space vehicles and infrastructure. The focus is on the development of material flammability experiments in microgravity that will both serve as validation experiments for results from other microgravity facilities and for model development.

This Topical Team aims at investigating the properties of soft materials such as Foams and Emulsions in microgravity. Foams are suspensions of bubbles of gas in a liquid. On earth only foams with a small content of liquid are stable, while more wet foams are unstable because of drainage, the sedimentation of water due to gravity. Therefore, this Topical Team aims at investigating wet foams on the ISS using an instrument called Soft Matter Dynamics (SMD) which enables the study of such systems. The team is especially interested in coarsening events which are masked on ground by the drainage. Similarly, emulsions are dispersions of two immiscible fluids such as oil and water. On earth the two liquids separate because of gravity, giving rase to creaming. The science team is interested in performing experiments on SMD to study effects of coalescence and coarsening disentangled by creaming.

This Topical Team on Geodesy, Clocks & Time Transfer develops specific applications of clocks in space. They range from measurement of geopotential differences by distant clock comparisons, clocks synchronization and time transfer experiments, generation and distribution of atomic time scales, ranging experiments, in the optical and microwave domain, GNSS time and frequency transfer, study of atmospheric propagation delays. The Topical Team will support the exploitation of the ACES mission in the research areas listed above and contribute to the definition of future scientific missions based on atomic clocks and high- performance time & frequency links in space

The aim of the Giant Fluctuations Topical Team is the investigation of non-equilibrium fluctuations associated to diffusion in complex fluids in the absence of gravity. These conditions cannot be easily tackled by theoretical models, such as transient diffusion, concentrated samples and large gradients, also in comparison to computational results. The focus of this Topical Team is on the investigation of non-equilibrium fluctuations in complex liquids, because of the rich phenomenology that can be attained by tuning the interactions in such systems. Since gravity quenches long-wavelength non-equilibrium fluctuations, it is important to study such phenomena under microgravity conditions to fully exploit the scale-free behaviour of the fluctuations.

The purpose of this Topical Team is to initiate the activities in the framework of the integrated ESA–CSMA research project between Chinese and European science teams (acronym GRASP). This will take the shape of a kick-off meeting with the joint team at a convenient location in China (possibly at the prospective project coordinator from the Chinese side, Shanghai Jiao Tong University, Shanghai).

The meeting is requested by the involved space agencies and will be used to fulfil the following three tasks:

1. Work on a detailed implementation plan for the joint research project.
2. Discuss and consolidate complementary information to formalise the project application.
3. Further familiarise all project participants with each other.

This Topical Team, “Chemo-hydrodynamic pattern formation at interfaces” (CHYPI), focuses on the experimental and theoretical study of spatio-temporal patterns and dynamics occurring because of the coupling between chemical reactions and hydrodynamics. It is also about the analysis of the past Chemically Driven Interfacial Convection (CDIC) experiments on board of parabolic and sounding rocket flights, and the study of the relative role of buoyancy- and Marangoni flows triggered by chemical reactions in liquid solutions.

Dust agglomeration experiments in micro-gravity. In a broad context, the scientific objectives of ICAPS are the study of dust-dust interactions, dust-gas interactions, dust-light interactions, dust-light-gas interactions. ICAPS aims at providing answers to the following questions:

• What is the nature of interplanetary and interstellar dust?
• What is the mass, structure and motion of small dust aggregates?
• How can we interpret the astronomical observations of light scattered by such dust?
• How did the planets form in the early solar system?
• What are the interactions of aggregates with cosmic radiation?

The design and synthesis of energy efficient (photo-)electrochemical interfaces with tailored properties for accelerating and directing chemical transformations are key to developing new alternative energy conversion and storage systems for terrestrial and space applications such as fuel cells, electrolysers, batteries and so-called photoelectrochemical ‘solar fuel devices’, converting sunlight into chemical fuels. For the further development of these systems, it is crucial to get a better, fundamental understanding of the involved (photo-)electrochemical interface processes on multiple scales. Gas bubble formation dynamics and convective transport on the electrode surface represent such key processes. They strongly influence the energy efficiency of an electrochemical system by affecting mass transfer properties and reaction overpotentials due to solution and electrode resistances. These parameters are particularly exacerbated under reduced gravitational environments as the gas bubble break-off diameter directly depends on the gravitational force.

This Topical Team is investigating the fundamental processes of (photo-)electrochemical interface phenomena such as gas bubble formation and their impact on electrode reactions in terrestrial and reduced gravitational environments. The aim is to focus on reactions with significant relevance for human space exploration such as the hydrogen evolution reaction (HER) and more complex proton-coupled electron transfer (PCET) reactions such as the oxygen evolution reaction (OER) and CO2 reduction reactions.

The aim of this Topical Team is to bring forward the collaboration of the Europeans teams involved in Colloids experiments and Fluid mixtures experiments with Chinese scientists. In particular the Chinese scientists have been involved in the past in the SCCO project and they are now also interested in the Giant Fluctuations experiments. In addition, the Chinese science team are involved in experiment on the rheology of colloidal suspensions such as gels and glass. These experiments are of interest of the European science team too. The European science team will perform similar experiments on the ISS using thermal stresses. The experiments on the CSS and the ISS are therefore complementary.

The aim of this Topical Team is to study the thermo-diffusion effect and accompanying diffusion processes as well as their inherent relation to fluid non-equilibrium thermodynamics. The underlying mechanisms are still poorly understood. Although microgravity experiments have been performed these studies could be extended to the phenomena in binary mixtures, looking at technological applications.

Compared to solidification, melting of metallic materials received very little interest over the last decades. However, the development of new processes and materials (notably relating to additive manufacturing and joining of dissimilar materials) has led to a resurgent interest in this scientifically challenging topic.

Against this background, two key scientific questions have been raised that are addressed in the frame of this collaboration.

1. Stability of the solid/liquid interface and morphological transition during melting
   • Stability of the solid/liquid interface during solutal melting (dissolution)
   • Morphology and kinetics of multi-phase solid/liquid interfaces
2. Conditions at solid/liquid interfaces
   • Off-equilibrium conditions during dissolution
   • Phase selection during melting of multi-phase alloys

This Topical Team gathers scientists from across Europe to set-up the basis of a project-based collaboration.