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The Ørsted Satellite

The Ørsted Satellite - The First Danish Satellite

The Ørsted Satellite

The Ørsted Satellite was the first ever Danish satellite. It was launched on the 23rd of February 1999 with an American Delta II rocket from Vandenberg Air Force Base in California.

The Ørsted Satellite

The Ørsted Satellite - The First Danish Satellite

The Ørsted Satellite

The Ørsted Satellite was the first ever Danish satellite. It was launched on the 23rd of February 1999 with an American Delta II rocket from Vandenberg Air Force Base in California.

The Ørsted satellite was the first satellite developed and built in Denmark and it was the first in the Danish small satellite programme. The satellite only weighed 60.7 kg and measured 72 × 45 × 35 cm when folded, which in the context of space travel was small.

The primary task of Ørsted was to measure the direction and strength of the Earth's magnetic field; i.e. a mapping of the magnetic field, and monitor the high-energy charged particles.

THE CONTROL SYSTEM OF THE ØRSTED SATELLITE

The task related to Aalborg University, in the development of the Ørsted Satellite, was to design, implement, and commission the attitude determination and control system. 

The principle behind the control of Ørsted was quite simple and has its roots back to Hans Christian Ørsted's discovery of electromagnetism in 1820. He discovered that a magnetic field is formed when current is sent through a wire. By placing a magnetic needle close to a current-carrying wire, Ørsted showed that the magnetic needle adjusted itself according to the wire's magnetic field.

Mogens Blanke
A model of the Ørsted satellite under test at Aalborg University. Ørsted's control system went through a long series of tests before launch. Among other things. the detumbling was tested in a laboratory at AAU, where a model of the satellite suspended in an air bearing enabled a simulation of the satellite's movement without the influence of gravity. The picture shows Professor Mogens Blanke.

The Ørsted satellite used the same principle to control speed and orientation. Power was sent through three sets of coils mounted at right angles to each other inside the satellite body. This allowed the creation of a magnetic field in any direction. With current in the coils, the Ørsted satellite was therefore able to turn in the Earth's magnetic field - just like a compass needle in a scout's compass. One thus exploits the fact that a current-carrying wire (here the coils) is affected by a force when it is exposed to a magnetic field. In Ørsted's case, the Earth's own magnetic field was used to set off.

Ørsted was thereby the first space craft ever that was controlled in all three directions with Earth’s magnetic field. By mounting three coils in the satellite's body, the satellite could be almost controlled in three dimensions ensuring a very precise control of the satellite.

Some of the main forces behind the development of the control system was among others Thomas Bak, Rafal Wisniewski, and Mogens Blanke as shown in the picture.

INDUSTRY AND UNIVERSITIES IN FOCUSED COOPERATION

The Ørsted satellite project started in 1993 after the acceptance of the project in the Danish Parliament, and has involved many research institutions and business enterprises. The project is still today an excellent example of how industry and universities can work together on one focused project.

The total budget of the project was DKK 130 million. At the beginning of 2002, an additional DKK 651,000 was given to continue the project for 3 years.

In addition to the direct support from the Danish state, the Ørsted satellite also received support from NASA, which paid for the launch of the satellite; The European Space Agency (ESA), which paid for the testing of the satellite at ESA's facility ESTEC in the Netherlands. The French CNES contributed with the Overhauser magnetometer, and the German DARA supported the project with a test of the Ørsted satellite's solar panels at their solar test facility in Munich.

Ørsted Project Partners

Project Facts

PROJECT NAME
The Ørsted Satellite

EFFECTIVE START/END DATE
Satellite launched in 1999

PROJECT PARTNERS

  • Aalborg University
  • Technical University of Denmark
  • Terma
  • Danish Meteorological Institute
  • Computer Resources International

AAU Space Group

Associated Researchers