Odin is a Swedish dual disciplinary (astrophysics and atmospheric science) spacecraft. The 250 kg, 340 W spacecraft has a pointing accuracy of 15 arcsec and a data storage capacity of 100 MB. It carries a cryogeneic radiometer to monitor three mm-bands at 118.25-119.25, 486.1-503.9, and 541.0-580.4 GHz, at a resolution of 0.1-1.0 MHz. It carries also a cryogenic Optical Spectrometer to cover three visible and infrared bands at 280-800 nm, and another infrared band at 1,270 nm.

The target gases of astrophysical interest are clorine iodide (CI), water vapor, hydrogen sulfide, ammonia and a few others. For atmospheric studies, the gases are clorine monoxide, nitrous oxide, nitrogen dioxide, hydrogen peroxide, nitrous oxide, nitric acid, and a few others. Both instruments were few by a 1,1 meter Gregorian telescope.