While a satellite turning 10 years is no big deal on its own, the Ørsted satellite is remarkable in many ways. Despite a very low budget, it provided highly valuable science results published in many prominent scientific journals and graced the cover pages of Geophysical Research Letters, Nature and Eos. Former NASA Administrator Daniel Goldin was rumored to have a model of the Ørsted satellite on display in his office, because it exemplified his "faster, better, cheaper" philosophy.
Ørsted was originally designed to have an operational life time of 14 months, which was eventually extended to a few years. Today, 10 years later, you can still hear it transmit science data in the 2.2 GHz satellite band.
Ørsted is also a satellite that has survived a close encounter with another spacecraft. On March 20, 2001, Ørsted was merely 3.25 km away from collision with the Argentinean SAC-C satellite - a distance that at orbital velocities corresponds to no more than half a second!
In 2010, Ørsted will be replaced by the European Space Agency's Swarm mission. Swarm will consist of three identical satellites that will measure Earth's magnefic field with even higher presicision and resolution. The concept has been developed by Danish scientists and is based on the experience gained through the Ørsetd mission.
The Ørsted satellite by Jan Erik Rasmussen, DTU Space.