CETSOL-1 is a European Space Agency (ESA) experiment that belongs to the Transparent Alloys series, which aims to study different physical phenomena that take place during directional solidifications under microgravity conditions. In particular, the goal of this new experiment is to identify the growth of the columnar structures (known as dentrites), the equiaxed grains, the mixed formation of both structures as well as the physical mechanisms that intervene in their evolution. The microgravity conditions of the ISS allow the science team to study three dimensional phenomena without the influence of natural convection, so the experiment is performed in pure diffusive conditions. This way, it is possible to better understand the behaviour of the materials, a knowledge that will be useful for future innovation.
Úrsula Martínez, PhD student and researcher at E-USOC, preparing the scientific sample in its cartridge for later coupling and process in the Transparent Alloys instrument during experiment preparation on ground.
The experiment was proposed by Access e.V (RWTH Aachen University) researchers, Gerhard Zimmermann and Laszlo Sturz, to the European Space Agency (ESA) and will be executed during the April-June 2022 period in the U.S Laboratory inside the Microgravity Science Glovebox (MSG). The experiment had previously arrived in the Cygnus NG-17 capsule.
E-USOC is responsible for the execution of the science campaign on board the International Space Station as well as its previous preparation on ground. We define all the documentation needed to perform the experiment’s operations, that is, the system procedures and the execution scripts. The procedures indicate how to command the experiment and establish the operations plan while the scripts are the way we tell the experiment, through software, the scientific test we want to perform. The main parameters used for this experiment are the solidification velocity and the thermal gradient applied in order to study their influence on the solidification process. Apart from performing science and in collaboration with NASA’s Payloads Operations Integration Center (POIC), we prepare the procedures that astronauts must follow for the experiment installation in MSG and we monitor the actual installation to give support and ensure that everything goes as planned. We also develop the planification products so that the resources used during the execution are optimized.
Matthias Maurer, ESA’s astronaut, with the Transparent Alloys instrument after its successful installation in MSG. Credits ESA and NASA
The Transparent Alloys series that E-USOC prepares and executes consists of five experiments being CETSOL-1 the fourth of them. Usually, the study of the characteristic structures that grow during the solidification of metals is done through destructive techniques or via X-ray after the solidification is completed. The technology implemented in the transparent alloys instrument makes it possible to observe this process in real time, giving the science community valuable information on how metal alloys behave during solidification that could be used, for example, to improve and optimize industrial procedures. The transparent Alloys experiments are SEBA1 (2018), SETA (2020), METCOMP (2021), CETSOL-1 (2022) and CETSOL-2 (planned on 2024), and each one of them has specific objectives to characterize the different microstructures, growing dynamics and parameters that intervene in the solidification process.
Microstructure developed during a directional solidification of the CETSOL-1 experiment. Credits CETSOL-team (PI Access e.V.).
The installation of CETSOL-1 was successful and science runs are being currently executed. Microgravity experiments are of great use for the science community and the E-USOC will keep preparing, executing and supporting these experiments.