Against strong international competition, SpaceTech has been awarded a contract by the Turkish government institute TÜBITAK UZAY to deliver the GökTürk-2 solar array system consisting of
- 3 solar panels including the photovoltaic assembly
- the solar panel deployment mechanisms
- the pyro drive module (PDM) electronics executing the deployment sequence of the mechanism
The solar panel delivery included three flight models and three qualification model units. One of the QM panels has been equipped with active cells, the remaining two with mass dummies only.
Each of the three panels on the spacecraft consists of four arrays with 3 strings of 20 cells each. In addition to the cells temperature sensors for thermal control, thermistors as input to the satellite's maximum power point tracker as well as bleed resistors for controlled insulation with the spacecraft body are accommodated on each panel.
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.
The qualification and flight models of the solar array system have been delivered to Turkey in 2010 and 2011, respectively. The satellite has been launched and the solar array successfully deployed in December 2012.
GökTürk-2 is an earth observation satellite program initiated by the Turkish government institute TÜBITAK UZAY in an effort to develop its satellite system and subsystem design and development capabilities as well as to establish a bus platform for future remote-sensing missions. The main payload consists of a multi-spectral imager (MSI). The spacecraft is specified for an operational life time of 5 years in a sun-synchronous orbit at an altitude of approximately 700 km and a local time of descending node between 10:30 and 11:30 a.m.