Cooling system for the MEESST MHD heat flux and radio blackout mitigation HTS Magnet probe

Radio Blackout and extreme heat fluxes are major problems occurring during spacecraft (re-)entry into planet’s atmospheres. Both occur at the front surface of the spacecraft due to the compressed and partially ionized plasma. Both can be catastrophic for the mission with protection material losses due to heat or the complete loss of GPS data telemetry or communication with ground stations for extended periods of time. The MEESST (Magneto-Hydro-Dynamic Enhanced Entry System for Space Transportation) European project investigates a mitigation solution for both effects by developing simulation tools and ground-based plasma experiments based on the use of magneto-hydro-dynamic (MHD). An experimental probe was designed and manufactured to study radio-blackout and heat-flux-mitigation in plasma wind tunnels at the Von Karman Institute for Fluid Dynamics (VKI, Belgium) and at the Institute of Space Systems (IRS, Germany), respectively. The probe encompasses a non-insulated and conduction-cooled HTS magnet, operating near 20 K and producing the magnetic field required for the MHD plasma experiments. The magnet is housed in a cryostat surrounded by a water-cooled shell, designed to protect the probe from the plasma jet heat. While the operation of the probe in the plasma environment was rather challenging, the magnet and the cooling system behaviors were quite stable during the first campaign of experiment at VKI. We report, here, on the design of the probe, detailing the main design points with regards to the cooling system, including the cryogenic loop required to maintain the 5-pancakes REBCO (Rare Earth-Barium-Copper-Oxide) magnet near 20K, and the external water-cooled shell designed to sustain the extreme heat fluxes imposed by the plasma. We will finish with a brief overview of the tests performed to demonstrate the expected operation of the system in its test environment. Acknowledgement : The MEESST project has received funding from the European Union’s Horizon 2020 research and innovation program under grant ...