Various systems may benefit from appropriate thermal protection. For example, various flight recorder systems may benefit from thermal isolation of a flight recorder memory core. A system can include a memory core of a flight recorder. The system can also include an inner chamber housing the memory core. The system can further include an outer chamber housing the inner chamber with a vacuum between the inner chamber and the outer chamber. The system can additionally include a signal path from avionics equipment to the memory core through the outer chamber and the inner chamber. The system can also include a power path for the memory core through the outer chamber and the inner chamber.