SpaceX has laid out further details about a 4,425-satellite communications network that’s expected to provide global broadband internet access, with its Seattle-area office playing a key role in its development.

The plan is explained in an application and supporting documents filed on Tuesday with the Federal Communications Commission.

SpaceX is only one of several ventures aiming to deploy satellite-based internet services over the next few years. The others include OneWeb, a consortium with backing from Airbus, Virgin Galactic and other telecom players; and the Boeing Co., which envisions a low-Earth-orbit constellation with more than 1,000 satellites.

OneWeb is up against a 2019 regulatory deadline for beginning its service, but the time frame is squishier for SpaceX and Boeing.

In the technical information that accompanied its application, SpaceX said it would start commercial broadband service with 800 satellites. That service would cover areas of the globe from 15 degrees north to 60 degrees north, and from 15 degrees south to 60 degrees south. That leaves out some portions of Alaska, which would require a temporary waiver from the FCC.

Eventually, the network would grow to 4,425 satellites, transmitting in the Ku and Ka frequency bands.

“Once fully deployed, the SpaceX system will pass over virtually all parts of the Earth’s surface and therefore, in principle, have the ability to provide ubiquitous global service,” SpaceX said.

The satellites would orbit the planet at altitudes ranging from 714 to 823 miles (1,150 to 1,325 kilometers) – well above the International Space Station, but well below geostationary satellites. SpaceX said it would follow federal guidelines to mitigate orbital debris.

Each satellite would weigh 850 pounds (386 kilograms) and measure 13 by 6 by 4 feet (4 by 1.8 by 1.2 meters), plus solar arrays, SpaceX said. Operating lifetime was estimated at five to seven years per satellite.

SpaceX still has to get approval for network operations from the FCC as well as the International Telecommunication Union. The ITU filings are being made on SpaceX’s behalf by the U.S. government (under the name USASAT NGSO-3) and the Norwegian government (as STEAM).

Last year the California-based company established an office in Redmond, Wash., to focus on the satellite project. When SpaceX CEO Elon Musk announced the project in Seattle, he said as many as 1,000 employees could eventually be working in Redmond.

Back then, Musk estimated that it’d take about five years and $10 billion to get the satellite project off the ground.

SpaceX suffered a setback in September when a Falcon 9 rocket and its satellite payload were destroyed in a launch pad explosion in Florida. This month, Musk indicated that the investigation was closing in on the root cause and that SpaceX could “be back to launching around mid-December.”

Tip o’ the hat to Secure World Foundation’s Brian Weeden and Parabolic Arc’s Doug Messier.