Because the satellites are lower, they travel faster. Thus, Starlink must provide a constellation of satellites whizzing around the planet. When one satellite moves away from one of its customers, another one must come into view in order to provide a continuous internet connection.

Mark Juncosa, vice president for vehicle engineering at SpaceX, said that with 12 additional launches, SpaceX could provide good coverage over the United States; 24 launches would put enough satellites to cover most populated areas; and 30 would cover the entire world.

If Starlink is successful, more satellites would be added to send and receive greater volumes of data.

Are other companies also looking to launch constellations of internet satellites?

Starlink’s competitors include OneWeb, Telesat, Iridium and Amazon.

Why is SpaceX, a rocket company, going into the internet business?

For Mr. Musk’s dream of sending people to Mars, he is developing a giant spacecraft called Starship. He noted that SpaceX’s rocket launching business might grow to about $3 billion a year. By contrast, internet revenue could bring in $30 billion a year for the company, Mr. Musk said.

“We see this as a way for SpaceX to generate revenue that can be used to develop more and more advanced rockets and spaceships,” Mr. Musk said. “We think this is a key steppingstone on the way to establishing a self-sustaining city on Mars and a base on the moon.”

Mr. Musk acknowledged that history is full of companies dragged into financial ruin by attempting to build ambitious constellations of communications satellites.