Axial Grooved Heat Pipes Delta Qualification Programme

Status date

The main objective of the project was to perform a Delta Qualification Programme of Axially Grooved Heat Pipes (AGHPs) as requested in the ESA standard PSS-49 (TST-01) Issue 2 (March 2003). The main features of this AGHP technology were transferred from TAIS, Russia to IberEspacio.

Following this technology transfer, there were two main areas of focus for the re-qualification of the heat pipes:

  • Manufacturing procedures and processes,
  • Change of location of manufacturing facility.

In the frame of this Delta Qualification Programme, IberEspacio has made a complete specification of the heat pipes, and manufactured and tested a predefined set of AGHPs to verify their compliance with the performance and quality requirements.


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All AGHPs submitted to the Delta Qualification Programme were constant conductance heat pipes made of an aluminium alloy. They were charged with high purity ammonia as working fluid. The AGHPs use longitudinal re-entrant grooves. The AGHP profiles have been used in several space applications. They benefit from an unequalled flight heritage, accumulating significant flight duration in space.

The operational temperature range of the AGHPs is specified to be between –50ºC and +80ºC in the frame of this programme.


The project plan was divided in two phases:

  • Manufacturing of Heat Pipes with two different profiles in order to validate the manufacturing process.
  • Performing the Test Campaign to demonstrate the compliance with the ESA PSS-49 standard requirements.
Current status

The project was officially completed in December 2007.

All the tests performed during the Test Campaign were successful, and all the AGHPs and samples achieved the values required by the ESA PSS-49 standard.

The AGHPs manufactured are still in a continuous lifetime test having at the moment around 9000 accumulated hours without showing any performance degradation.