Passive and Hybrid Thermal Solutions

Passive and hybrid thermal solutions are the backbone of spacecraft and aerospace thermal design because they use the physics of phase change and conductivity rather than bulky, failure-prone pumps. Here’s a more detailed breakdown of how each plays into Space, Aerospace & Defence systems:

• Heat Pipes – Reliable, lightweight transport of heat over distances with no moving parts. Sealed tubes filled with a working fluid that evaporates at the hot end, travels as vapour, condenses at the cold end, and returns via capillary action

  Application: Cooling avionics racks, radar modules, spacecraft panels, and optical sensors. On satellites, they move waste heat from electronics to radiators without adding mass

• Loop Heat Pipes (LHPs) – High-capacity, long-distance heat transport; ideal for satellite bus and payload cooling. Similar to heat pipes but with separate evaporator and compensation chamber; capable of transporting kilowatts of heat over meters with minimal temperature drop

  Application: Satellite buses, payload cooling, high-power instruments, and telecom spacecraft. They excel at routing heat around bends and across long distances, making them essential for distributed satellite payload

• Vapour Chambers – Spreading high local heat loads from electronics and payloads across radiators. Flat, planar versions of heat pipes, optimized for spreading intense heat from small footprints across larger surfaces

  Application: Payload electronics boards, power amplifiers, star trackers, and high-density avionics. They spread hot spots evenly before coupling to radiators or cold plates

• k-Core® Annealed Pyrolytic Graphite (APG) – Ultra-high in-plane conductivity for lightweight thermal straps, enclosures, and panels. Graphite engineered for ultra-high in-plane conductivity, encapsulated in lightweight metal structures to form panels, straps, or enclosures

  Application: Thermal straps to link sensitive instruments to radiators, lightweight radiator panels for satellites, and battery enclosures requiring temperature uniformity. Its conductivity rivals copper but at a fraction of the weight.