Liftoff of a Falcon 9 rocket carrying 60 spacecraft is scheduled at 8:37 p.m. EST from Complex 39 at Kennedy Space Center. SpaceX has launched more than 1,000 Starlink satellites, although some of those deorbited and burned up in the atmosphere as they were designed to do.

Ultimately, the company plans to launch up to 12,000 satellites, but with a high replacement rate because each spacecraft's life expectancy is only a few years.

Starlink Internet service is available in northern regions of the United States, Canada and the United Kingdom, but the service area is moving south.

Starlink's website recently sent out an alert saying the service was available to limited numbers of new subscribers in Central Florida, for example.

The service currently provides download speeds of about 100 megabits per second, but that is changing as SpaceX develops the system, according to Musk's posts on Twitter.

The Federal Communication Commission defines 25 megabits per second or higher as "high-speed" Internet service.

"You might see much higher download speeds on Starlink at times. Testing system upgrades," Musk tweeted Wednesday.

SpaceX completed a test firing of the rocket Wednesday, the company said on Twitter.

The weather forecast for the space center Sunday evening calls for partly cloudy skies, with a low around 65. Winds from the south-southeast are expected to be light, according to the National Weather Service.

Source: United Press International