S5P Solar Array

SpaceTech has developed and delivered the Deployable Solar Array Panel (DSAP) system for the ESA mission Sentinel-5 Precursor under a contract by Astrium U.K. Ltd. The DSAP consists of

  • 3 solar panels including the photovoltaic assembly
  • the solar panel deployment mechanisms

S5P solar panels

Each of the three panels on the spacecraft consists of 2 sections with 15 strings of 19 cells each. As the design of the deployment mechanisms do not require any front side inserts, the area can be fully used for an efficient and straight-forward cell laydown. In addition to the cells temperature sensors for housekeeping purposes as well as bleed resistors for controlled insulation with the spacecraft body are accommodated on each panel.

DSC03929 normS5P solar panel string layout

Third generation AZUR cells with a rated efficiency of 28 % are used to make up the photovoltaic assembly. Each cell is protected with a by-pass diode and each solar string by a blocking diode.


S5P solar array deployment mechanisms

The deployment mechanism consists of a of a hold-down-and-release-mechanism (HDRM), a spring driven cam system with high torque margin a CFRP strut with metal tape spring hinges, an a damper system to reach a very low latching shock. Once deployed the strut design features very high stiffness supporting a high satellite agility.

S5P launch

The flight models of the deployable solar arrays were delivered to Airbus in September 2014. The Sentinel-5 Precursor satellite has been launched on 13 October 2017 on a Rocket launch vehicle from the Cosmodrome in Plesetsk (Russia).

Watch the video with information on the mission and interview with STI's project manager here.


The Sentinel-5 Precursor mission (S5P) is part of the Global Monitoring for Environment and Security initiative (GMES), which is a joint undertaking of the European Community and the European Space Agency (ESA). The S5P spacecraft, which was developed under the auspices Astrium U.K. Ltd, is flying in a Sun Synchronous near-polar orbit of 820 km altitude and 13.35 ascending node time.

The project work was carried out under a programme of and funded by the European Space Agency (ESA). The view expressed herein can in no way be taken to reflect the official opinion of the European Space Agency.

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