Phase Change Material Heat Accumulator for the HEXAFLY Hypersonic Glider

From the launchers to the spacecrafts, various on-board systems have to be maintained
within specified temperature limits. Phase Change Materials (PCM) offer the possibility to
store thermal energy directly as latent heat of fusion. Among the advantages of a PCM
device are the stability of temperature control, the absence of moving parts and a reduced
mass. The HEXAFLY-INTERNATIONAL project aims to flight test an experimental vehicle
above Mach 7 to verify its potential for a high aerodynamic efficiency during a free-flight.
European Major Resarch Centers and Industries are collaborating on this challenge. The
presented activity focus on the use of a Phase Change Material device already developed
under ESA projects up to TRL 6. Two efficient heat accumulators using PCM will allow
avoiding overheating of electronic units such as telemetry & telecommand receivers,
transmitters and data acquisition units for the hypersonic flight. The paper presents the
complete cycle of design and environmental testing for the two PCM Heat Accumulators
selected for the flight. The conclusions will show the benefit of adopting a Phase Change
Material Heat Accumulator.