The Proton rocket lifts off with Sirius 1. Photo: ILS

A revolutionary marriage between space and American motorists took a step closer to reality today when a Russian Proton rocket successfully launched a digital radio broadcasting satellite.

Liftoff occurred right on schedule at 2208:47 GMT (6:08:47 p.m. EDT) from pad 24 at the Baikonur Cosmodrome in Kazakhstan. In the first ten minutes of flight the three-staged Proton fired as planned, placing the Block DM upper stage and attached Sirius 1 satellite into a parking orbit.

The upper stage then performed two burns through the first two hours of the flight to place the satellite into highly elliptical, highly inclined perch above the planet. Spacecraft separation was successful and ground controls have established contact with Sirius 1.

Read our play-by-play call of the launch in the Mission Status Center. Also check out our timeline of launch events.

The satellite delivery mission was managed by International Launch Services -- a corporate venture between Lockheed Martin, Proton-maker Khrunichev and Block DM manufacturer Energia. This was the 15th ILS Proton launch since 1996.

Built by Space Systems/Loral, the 8,377-pound Sirius 1 is the first of three spacecraft to be launched this year for Sirius Satellite Radio, headquartered in New York City.

"The promise of satellite radio is seamless, coast-to-coast coverage across the continental United States, a system that will permit our customers to drive from New York to California and from Chicago to New Orleans and never lose the Sirius satellite signal," said Ira Bahr, Sirius' senior vice president for marketing.

Working in tandem, the three Sirius satellites will beam 100 channels of digital-quality audio programming directly to specially-designed receivers in customers' cars.

"The Sirius music experience will present a breath and depth of musical content that we don't think ever before been delivered," Bahr said.

The service, to be debut commercially early next year, will offer 50 channels of commercial free music and up to 50 channels of news, sports and entertainment programming. The cost: $9.95 per month.

Mission poster. Photo: ILS

Sirius is currently building a team of disc jockeys and behind-the-scenes staff to run the system from its broadcasting facility in New York City's Rockefeller Center.

Regularly scheduled shows are planned too, with artists like Sting, Grandmaster Flash and MC Lyte. Plus, Sirius has a strategic alliance with the John F. Kennedy Center for the Performing Arts and the National Symphony Orchestra.

Broadway music and entertainment is also in the works with Playbill on the "Broadway's Best" channel.

In addition, Sirius has forged alliances with CNBC, National Public Radio, Outdoor Life Networks, Sports Byline USA, Speedvision, USA Networks/SCI FI Channel, the BBC and Hispanic Radio Network to anchor the non-music channels of the system.

Some of the partners will simply simulcast their audio on Sirius, such as CNBC, while others will generate unique content exclusively for satellite radio, Bahr said.

Sirius has also entered into agreements with automobile manufacturers DaimlerChrysler, BMW, Ford, Jaguar, Mazda and Volvo to factory-install the satellite receivers, some beginning with the upcoming model year. That will account for up to 7 million vehicles per year, or half of the American production line.

Expect only the more expensive editions of the cars to come with the satellite receiver already installed at first.

For owners wanting to retrofit their existing cars, Bahr said there will be two options costing under $199. One will be replacing the existing car radio with a Sirius system; the other would be buying an adapter that will bring the satellite signal into your current radio via the FM input.

Constellation in the sky
Following today's launch, the Sirius-2 satellite is slated for liftoff in September with Sirius-3 following a month later, both aboard Proton rockets. A fourth satellite will be kept in ground storage as a spare.

An artist's concept of a Sirius satellite in space. Photo: SS/L

The craft will be strategically placed in egg-shaped orbits looping from 14,900 miles at the low point to 29,200 miles at the high end, inclined 63.4 degrees to either side of the equator. The satellites will be spread apart such that two are always in view of the U.S., and as one sets another one rises.

The orbit is unusual for a commercial communications satellites. Normally such satellites fly in circular geostationary orbit 22,300 miles high where the craft can match the Earth's spin and "park" over one spot of the globe.

But since Sirius aims to reach cars driving on the road with man-made and natural obstacles blocking the view to satellites flying above the equator, the special orbit plan was needed.

"What we discovered after testing that the geostationary satellite configuration does not provide high enough angles of elevation to deliver the seamlessness of coverage that we felt was really critical," Bahr said.

Potential roadblocks are anything from a 2-story building to tractor-trailers driving next to you.

"The result (of the Sirius orbit) is that we always have a satellite which is in excess of 60 degrees angle of elevation."

The only problem that still remains is big city skyscrapers. To combat that, Sirius plans to deploy 105 terrestrial repeaters in 46 cities that will pick up the satellites' signal and transmit the programming locally. The Sirius receiver will automatically switch from satellite to the local system as needed.

Sirius also is looking to bring its programming into Americans' homes via cable TV, direct-to-home TV satellite broadcasters and special receiving devices.

"We recognize a customer who likes our service in the car is probably going to want it at home, and we will deploy a number of different options to get the product in the home," Bahr said.

The other guy
Sirius Satellite Radio and competitor XM Radio were granted licenses by the Federal Communications Commission in 1997 for digital satellite radio broadcasting systems.

XM Radio tentatively plans to launch its first satellite aboard a Sea Launch Zenit 3SL rocket around November 18.

"This is a great new category and it is certainly large enough for two companies to be very successful," Bahr said.