Cosmic microwave background
The Sky Polarization Observatory (SPOrt) was an Italian instrument planned for launch to the International Space Station in for a planned 2-year mission beginning in 2007. There it would observe 80% of the sky for the Cosmic microwave background radiation in the frequency range from 20–100 GHz. Apart from detecting large scale CMB polarization it will also provide maps of Galactic synchrotron emission at lowest frequencies.