The internet-satellite megaconstellation is called Starlink and was first heard about back in 2015. Proposed plans for the network include 12,000 total satellites.
SpaceX founder Elon Musk has said only 400 would be needed for minor coverage and 800 would provide moderate coverage.
The second launch, set for May 2019, would send 60 satellites into orbit. These satellites would be a test and would lack the ability to communicate with each other. The first two test satellites were put into orbit in February.
Based on the results from the May launch there could be anywhere from 2-6 more launches in 2019. The company plans to have Starlink operational in some capacity by 2020.
