The Odin spacecraft is designed to serve both astronomy and aeronomy. For aeronomy the spacecraft follows the Earth limb - scanning the atmosphere up and down from 15 to 120 km at a rate of up to 40 scans per orbit. When observing astronomical sources Odin is continuously pointing towards the object for up to 60 minutes.
The Astronomy objective is to perform detailed studies of the physics and the chemistry
of the interstellar medium by observing emission from key species. The following classes
of objects will be main targets for observations:
- Giant molecular clouds and nearby dark clouds: The purpose is to improve our
understanding of the chemistry and the cooling processes of the interstellar medium and
thereby the conditions for star formation in particular by measuring lines from oxygen and
water molecules.
- Detection of protostars.
- Comets: Studies of the physics of outgassing of water, the size of active regions and
density estimates both in short and long period comets.
- Planets: Height distribution of trace elements in the atmospheres of Jupiter and Saturn.
Detection of minor constituents brought up by convection would provide information not
only on the dynamics but also on the physics and chemistry of the deep atmospheres.
- Circumstellar envelopes: Studies of the dynamics and chemical composition of outflows.
- Nearby galaxies: Estimates of star formation activity from observations of CO and H2O.
The aeronomy research will address scientific problem areas in the stratosphere and
mesosphere by making measurements of various trace species. The scientific goals can be
summarized as follows:
- Stratospheric ozone science: To elucidate the geographical extent of and mechanisms
responsible for ozone depletion in the "ozone hole" region and to study dilution
effects and possible heterogeneous chemistry even outside of the polar regions due to
sulphate aerosols
- Mesospheric ozone science: To establish the relative role of odd hydrogen chemistry and
the effects of ordered and turbulent transport and corpuscular radiation.
- Summer mesospheric science: To establish the variability of mesospheric water vapour
including an assessment of the required fluxes for aerosol formation in the polar
mesosphere.
- Coupling of atmospheric regions: To study some of the mechanisms that provide coupling
between the upper and lower atmosphere, eg downward transport of aurorally enhanced NO
with its effects on ozone photo chemistry and the vertical exchange of minor species such
as odd oxygen, CO and H2O.
Odin was designed and built by the Swedish Space Corporation (Svenska Rymdbolaget or
Rymdaktiebolaget).