PCDU Smart-1



Omnisys designed and produced the power conditioning and distribution unit, or PCDU, for the SMART-1 satellite, the first European spacecraft to travel to - and orbit - the moon.

SMART stands for Small Missions for Advanced Research and Technology and the prime contractor for the project was the Swedish Space Corporation. SMART-1 was a Swedish-designed satellite launched on September 27, 2003, from the Guiana Space Centre in French Guiana. During its mission the satellite made a large number of maps of the Moon’s composition, studying the distribution of minerals such as calcium, magnesium, aluminium, silicon and iron. After three years, on September 3, 2006, SMART-1 ended its mission through a controlled crash into the Moon’s Lake of Excellence.


  • The Smart-1 PCDU had several functions but its most important role was to condition and distribute power, essentially regulating the bus voltage under both sunlight and eclipse modes, controlling the discharge and charge functions of batteries.
  • The power conditioning system built around a modified S3R, or sequencing switching shunt regulator, topology. The PCDU regulated up to 2700 W of power on the 50 V bus and provided protected power to 41 consumers, including one 1500 W electric propulsion unit.
  • The power distribution part supplied the platform loads with switch and protected power.
  • The power control part was responsible for the health check of the on board processor boards and would, in the case of malfunction, have shut the failed controller down in a controlled manner and reboot the redundant one. During this phase, all necessary information would be stored within the PCDU.
  • The PCDU acted as a data acquisition system for some external critical signals, such as antenna switch and transponder status.


  • SMART-1 was the first mission in the ESA program called Small Missions for Advanced Research in Technology. Its main focus was to demonstrate technology of solar electric propulsion, reduction on fuel consumption and other deep space technologies such as efficient down-link of scientific data. It was also used to perform scientific observations of the moon surface.
  • Among the instruments onboard SMART-1 was a miniature colour camera for lunar imaging, an X-ray telescope for the identification of chemical elements on the lunar surface and an infrared spectrometer to analyse the minerals of the Moon. The main scientific objectives were to explore the origin of the Moon and to search for ice in the craters at the south pole of the Moon.
  • SMART-1 was launched in September 2003 and ended in September 2006 when it, in a planned manoeuvre, impacted the lunar surface in Lacus Excellentiae, a ”lunar lake” containing a crater, where properties of ejected materials could be observed.

For more information, please visit the Swedish Space Corporation (SSC) website.