Sirius Satellite Radio (previously known as CD Radio) is a satellite constellation to provide digital radio to mobile receivers in north America.
The Proton-K was a Russian, previously Soviet, carrier rocket derived from the earlier Proton. It was built by Khrunichev, and launched from sites 81 and 200 at the Baikonur Cosmodrome in Kazakhstan.
Khrunichev State Research and Production Space Center is a Moscow-based producer of spacecraft and space-launch systems, including the Proton and Rokot rockets and is currently developing the Angara rocket family. The Proton launch vehicle launches from Baikonur and Rokot launches from Baikonur and Plesetsk. Angara will launch from Plesetsk and Vostochny.INFO WIKI