The National Office for Aerospace Studies and Research (ONERA) has begun updating its facilities to simulate the space environment more effectively. The project, named HERMES, stands for High Energies for the iRradiation of Materials with Electrons and protonS. It aims to give France a new testing capability to assess how space materials and systems withstand radiation. The first phase of the project involves designing and building a new proton accelerator. On August 25, 2026, an international tender was awarded to NEC (National Electrostatics Corp.), a company based in Middleton, Wisconsin, USA. The equipment will be installed at ONERA’s site in Toulouse and is expected to be operational by the end of 2028. Meanwhile, the French firm Kardham has been assigned to design and oversee the expansion of the bunker that will house the accelerator, as well as the construction work. For over forty years, the particle accelerators at ONERA in Toulouse have simulated the effects of radiation that materials and equipment face in space. These facilities are used by industry, space agencies, and research organizations to study how systems age and whether they can function in space. The two accelerators currently in use were installed in the 1960s. Their replacement is the main goal of the HERMES program, which aims to improve ONERA’s capabilities in terms of energy levels, test precision, and irradiation options. Once completed, the program will include five electron and proton accelerators, capable of reaching 5 MeV of energy—double the current capacity of 2 MeV. These upgrades should allow for more accurate simulations of the effects of radiation on materials and components, helping to assess their durability and performance under various conditions, including those in low Earth orbit and future exploration missions. The Toulouse facilities have been used for over twenty years to test and qualify the solar generators of French satellites, as well as those of many European and international satellites. ONERA highlights the testing of the solar panels for the European Juice probe before its launch to Jupiter. In such programs, irradiation tests help evaluate how equipment behaves under the energetic particles and radiative conditions it will encounter during its mission. With HERMES, ONERA aims to maintain this testing capability in the long term and adapt it to the growing needs of the space sector, including the expansion of satellite constellations and the increasing demands of civilian, military, and exploration missions. For ONERA, mastering the ability to study and qualify resistance to radiation in France is a matter of national sovereignty. These facilities allow testing to be conducted on French soil, providing independent expertise for space programs. The new facilities must meet the needs of the civil space sector but also address the specific requirements of defense space systems. They can also be used to prepare missions requiring equipment that can function in more extreme radiative environments than those found in low Earth orbit. Emmanuel Chiva, president and chief executive of ONERA, describes HERMES as an investment to preserve French and European capabilities in simulating space environments. He says the program must support both civilian and military ambitions in space while preparing the technologies needed for future systems. The HERMES program is managed by ONERA with support from the Occitanie Region, the European funds management authority, and the prefecture of the Occitanie region. Funding includes 1.62 million euros from the European Regional Development Fund (FEDER), 1.5 million euros from the National Fund for Territorial Development and Planning (FNADT), and 2.2 million euros from ONERA’s own funds, allocated through the Defense Innovation Agency and the Direction General of Armaments. The commissioning of the first accelerator in Toulouse by the end of 2028 will mark the program’s first major operational step. The remaining equipment will then allow ONERA to have a complete set of tools dedicated to radiation resistance testing. ONERA, placed under the tutelage of the French Ministry of the Armed Forces, is the country’s aerospace research center. It employs around 2,200 people and had a budget of 312 million euros in 2025. Its work spans aviation, space, and defense, and it collaborates with public authorities, academic institutions, and industry. ONERA contributes to technological development, risk reduction in industrial programs, doctoral training, and scientific expertise for public authorities. With HERMES, the organization aims to renew an infrastructure that has been used for decades to test space equipment. The program is essential for maintaining a strategic testing capacity that supports civil, military, and scientific sectors.