The Ørsted (Oersted) spacecraft was named after the Danish physicist Hans Christian Ørsted
(1771-1851), who discovered electromagnetism in 1820. The spacecraft primary science
objectives were to perform highly accurate and sensitive measurements of the geomagnetic
field and to perform global monitoring of the high energy charged particle environment.
The instrumentation consisted of two magnetometers (proton precession and fluxgate), a
star imager for attitude determination, a solid-state charged particle detector package,
and a GPS receiver. The Science Instrument Team is
responsible for the design of the instruments, while the Science Team is responsible for
the science mission planning and international science participation. The science data
obtained during the planned one-year mission will be used to derive an updated model of
the geomagnetic field and its secular variation and to study the magnetospheric
field-aligned currents and their relationship to ionospheric and solar wind conditions.
The principal research topics are in two areas:
- studies of the generation of the magnetic field in the fluid core and the magnetic and
electrical properties of the solid earth; and
- studies of earth's magnetic field as the controlling parameter of the magnetosphere and
of all the physical processes that take place in the earth's plasma environment, including
phenomena like aurora and magnetic storms.
To utilize the Oersted science data return, the plan is to establish an internationally
recognized research environment in the field of solar-terrestrial physics, a
Solar-Terrestrial Physics Laboratory, comprising magnetospheric, ionospheric, and
atmospheric physics in combination with research in the magnetic field of the earth.
Correlative studies will be carried out using observations from existing monitoring
stations in Greenland and other polar regions.
The spacecraft was launched as an auxiliary payload into a near-sun synchronous
elliptical polar orbit, with inclination about 96 degrees, perigee/apogee of about 630 /
850 km, and nodal drift rate 0.76 degree/day. It is gravity-gradient stabilized, with its
extendable 8-m boom aligned to and pointing away from the center of the earth. Active
attitude control is achieved using three-axis magnetic torqueing coils. The data system
features on-board monitoring and pre-processing. Data is stored in a 16-Mbyte on-board
memory and downlinked in packetized format when a ground station is in view.
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