Siruis XM should have a fifth satellite in place as an in-orbit spare sometime in mid October. According to a story from RIA Novosti, the satellite arrived at Russia's Baikonur Space Center aboard an Antonov 124 jumbo jet last week and has since been moved to a clean room facility for final tests and preparation before being loaded on a Proton M heavy carrier rocket.
The Proton M and its cargo are scheduled to lift off from the launch center in Kazakhstan on Oct. 14, conditions permitting. The Loral-built XM-5 satellite is reportedly scheduled for an orbital slot of 85 degrees west.
RIA Novosti notes that all four XM satellites now in orbit were also lofted by the Russian Proton M heavy launch vehicle.