Jovian entry probes experience extremely severe aerodynamic heating environment due to its 47km/s entry velocity into a hydrogen–helium atmosphere. During the Galileo development program, thermal protection system (TPS) was evaluated using hydrogen arc-jet heating facility and laser heating facilities; however, these facilities are no longer available today. To address this issue, we focused on the similarity between Jovian entry probe and the divertor of fusion reactors and established a TPS recession rate measurement method using high heat flux test facility (JEBIS) owned by the National Institutes for Quantum Science and Technology (QST). As a result, we successfully obtained fast recession behavior of carbon-phenolic material under approximately 200MW/m2 heat flux, corresponding to the Jovian entry environment. The evaluation results showed good agreement with those from NASA's hydrogen arc-jet and laser heating methods, demonstrating the applicability of the electron beam method to assessments of TPS performance for Jupiter entry probes.
