Pegasus DPR-DM. Deployable Panel Radiator Deployment Mechanism

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Pegasus DPR-DM. Deployable Panel Radiator Deployment Mechanism Pegasus DPR-DM. Deployable Panel Radiator Deployment Mechanism
Pegasus DPR-DM. Deployable Panel Radiator Deployment Mechanism
Pegasus DPR-DM. Deployable Panel Radiator Deployment Mechanism
  • Client: European Commission
  • Country: International
  • Start date: 2015
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In the frame of PEGASUS programme within EC H2020, a consortium composed by Thales France, Thales Italy, Iberespacio, Active Space, Tecnalia and SENER has developed a Deployable Panel Radiator (DPR) for GEO satellites.

SENER has developed and manufactured the Deployment Mechanism (DM) of the radiator combining it with the flexible hoses assembly developed by Iberespacio to route the Loop Heat Pipe (LHP) through the deployment mechanism.


  • It is a mechanism to deploy a radiator panel with all its flexible fluid lines and cables. The working part of the mechanism is attached to the fixed part by means of two spherical bearings.
  • The mechanism is driven by four clock springs, and deployment speed is regulated by one viscous damper in order to perform a smooth deployment.
  • The viscous damper provides an active thermal control by means of redundant heaters and thermistors. Finally, the mechanism is kept in the deployed position against the end-of-stroke stop limits by means of the residual torque of the deployment springs.


The concept behind this mechanism can be adapted to deploy any type of single-deployment appendage that requires additional torque due to flexible tubes and/or wiring. The novelty of the developed DM is the integration of the flexible hoses assembly and the deployment mechanism within a reduced allowable volume.

  • Characteristics:
  • Totally passive mechanism
  • Mass: 4.1 kg (without thermal hardware),
               7.7 kg (without thermal hardware)
  • Deployment range: 180º
  • Deployed angle precision: <±1º
  •  Stiffnesses:
    - Axis direction: 2E6 N/m
    - Radial on interface plane: 4E6 N/mm
    - Radial off plane: 10E6 N/mm
    - Rotation around the axis: 6E4 N·m/rad
  • Maximum loads:
    - Axis direction: 815 N
    - Radial on interface plane: 8014 N/mm
    - Radial off plane: 815 N
    - Maximum moment deployed: 150 N·m
  • Spring torque:
    - Stowed 24.9 N·m
    - Deployed: 13.4 N·m
  • Maximum friction torque: 2.6 N·m @ -65ºC
  • Dimensions: 545 x 200 x 150 mm3

Unión EuropeaThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 640143.

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