Sirius Satellite Radio has ordered a large, high-power geostationary-orbiting satellite from Space Systems/Loral for launch in late 2008 despite the fact it has a spare satellite designed for elliptical orbit already built, New York-based Sirius announced June 8.

The announcement reinforces industry speculation that Sirius plans to transition to a geostationary-orbit system and add video broadcasts to its current radio programming.

Industry officials have said that a geostationary satellite would make it easier for Sirius to add mobile video to its services. Loral said the Sirius-5 would feature a 9-meter-diameter unfurlable antenna “for highly concentrated transmissions to small, advanced devices.”

Sirius said it expects to pay about $260 million to build, launch and insure the Sirius-5 satellite, which will be based on Palo Alto, Calif.-based Space Systems/Loral’s 1300 satellite frame and will provide power at the end of its 15-year service life of 20 kilowatts.

The three Sirius satellites currently in orbit are capable of generating 9 kilowatts of power at the end of their service lives, according Loral.

Sirius said Loral had agreed to provide up to $100 million in vendor financing for the project, but that the company currently has no plans to use that financing.

Sirius provides satellite radio coverage in North America from three satellites in elliptical orbits, meaning broadcasts are handed off from one satellite to another in such a way that the spacecraft with the best angle high over the horizon is the one providing the programming to customers. All three of these satellites were built by Loral.

Sirius-4, also built by Loral, is in storage at Loral. It too was designed for elliptical orbit. Sirius spokesman Patrick Kelly said June 8 that the company has no current plans to launch that satellite. Kelly declined to comment on whether the new Loral order means Sirius will gradually transition to an all-geostationary design.

A geostationary satellite, located at 36,000 kilometers in altitude over the equator, remains in a fixed position relative to its user antennas and requires no handoff to other satellites. Most satellite telecommunications services use this orbit.

Sirius said it would launch Sirius-5 aboard an International Launch Services Proton M rocket. The company has an existing launch contract.