SIRIUS 2, also known as SD-RADIO 2 is an American geosynchronous communications spacecraft that was launched by a Proton-K rocket from Baikonur at 09:44 UT on 5 September 2000. It enables S-band digital radio broadcasts (music, news, and entertainment) directly or through urban relay stations to motorists in North America. The Sirius constellation was to be completed with the launch of a third spacecraft later the same year.

Launch Date: 2000-09-05
Launch Vehicle: Proton-K
Launch Site: Tyuratam (Baikonur Cosmodrome), Kazakhstan