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The Ørsted satellite

The Danish Ørsted satellite is a unique success.

The satellite

Ørsted's precise magnetic measurements formed the basis for the most accurate models of the Earth's magnetic field and were used both to explore movements in the Earth's core and to map anomalies in the Earth's crust.

At Terma, we managed the development of the complete mission and operations of the micro-satellite system. We designed the spacecraft with its highly specialized boom structure to facilitate the measurements with extremely sensitive magnetic instruments as well as the ground control structure to operate the satellite in its orbit.  

For the electronic systems, we developed a compact power supply unit design. This formed the basis for the subsequent development of a complete modular system for scientific spacecraft with special facilities for automatic optimization of the performance in varying environmental conditions.

The Ørsted satellite is a significant technical achievement - the satellite has been awarded an honorable fourth place by the Danish Society of Engineers in the competition for "The 20th century's greatest Danish technical achievement". Thus, a technical achievement with our name on it!

The satellite was the first all-Danish satellite and the mission proved to be a great success. It demonstrated the ability of small satellites to deliver science of a high international standard and marked the beginning of a new era in measuring and monitoring the Earth's magnetic field.  

It further demonstrated that these types of measurements could be performed at modest cost by normal satellite standards. In April 2002, this was acknowledged when the mission made the cover of Nature. Already in its first year, the mission produced data of such volume and quality that the International Geomagnetic Reference Model for 2000 to 2004 was based on this data. Subsequently, four international conferences were centered on the new magnetic measurements from Ørsted and the follow-on missions, SAC-C (Ørsted 2) and CHAMP.



Ørsted's precise magnetic measurements formed the basis for the most accurate models of the Earth's magnetic field and were used both to explore movements in the Earth's core and to map anomalies in the Earth's crust. The measurements were used for the mapping of power systems in space and in studies of the solar wind's coupling with the Earth's upper atmosphere.

Ørsted's measurements of energetic particle radiation have provided new information on radiation problems for computers on board satellites in the Earth's radiation belts or above the arctic areas during solar eruptions.

Measurements with Ørsted's GPS instrumentation have contributed to the development of GPS-based atmospheric probing for meteorological applications. 

In connection with Ørsted, new software technologies were developed and applied which are used for most space missions today. Ørsted exceeded the previous limits with regard to software functionality, accuracy, and compactness.

Ørsted became the starting point for a brand-new technology for compact mounting of power components, an assembly technology which results in a decrease of the satellite power system's weight and volume.

Ørsted sowed the seeds for the development of a new technology within power electronics. Today, this technology is used on missions to Mars, Venus, and Mercury, among others. On Ørsted, the satellite checkout and mission control functions were combined in a brand new way. The same principle is now used by ESA, for instance on their most advanced scientific mission Herschel/Planck.

As an additional benefit of the project, ESA later build an ambitious new satellite mission, Swarm, based on the scientific expertise built up via the Ørsted mission. The concept was developed by Danish researchers and consisted of three identical satellites which measured the magnetic field.

But the Ørsted satellite project should also be highlighted as an organizational achievement as the project became a success based on a close collaboration between industry, universities, and other public institutions.

The national collaboration has involved six universities and research institutions and eight industrial companies.

The international collaboration includes the huge space agencies of NASA, ESA, CNES (France), and DLR (Germany), and more than 40 universities and research institutions worldwide. Based on Ørsted's measurements, more than 300 scientific, technical, and other specialized publications and articles have been published in international journals.

The Ørsted satellite was launched in February 1999. The satellite is still in orbit and functional even though not used to produce scientific data any longer.