In the frame of an ESA technology programme, the development of a High Capacity Grooved Heat Pipe (HGP), based on the thermal requirements of the next generation of telecommunication satellites, was contracted to SABCA.
After a trade-off and a design study, the selected concept was an aluminium extruded heat pipe (outer diameter of 25 mm) based on a multi re-entrant grooves design. This heat pipe was submitted to an acceptance test campaign: leak, proof, burst tests as well as thermal performance tests (maximum heat transport capacity, maximum tilt capability, start-up, priming, bending influence, ageing / gas plug, non-uniform heat input).
The test results showed for the multi re-entrant groove heat pipe a good confidence in the design and the fulfilment of the required specifications on heat transport and on tilt capability (experimental maximum heat transport capability of 1500 Watt-metres for a vapour temperature of 20°C -with ammonia-).
Based on this HGP concept, similar heat pipes have been developed with various outer diameters (11 mm, 15 mm and 20 mm) and with various shapes (circular outer shapes, integrated saddles).
Several of these heat pipes were tested during two parabolic flight campaigns, by varying the heat loads during the micro-gravity periods.
This HGP heat pipe family is now being submitted to a space qualification programme according to ESA standards (ESA PSS-49), both in straight and bent configuration. Within this qualification, the heat pipes are submitted to an extended test campaign including environmental (random/sinus vibration, constant acceleration) and thermal tests (thermal performance, thermal cycles, thermal soak, ageing).