SpaceX plans to launch satellites to beam the Internet to earth.

Elon Musk is ready to put his plan for beaming the Internet from small satellites into motion. His company, Space X was expected to launch two satellites in what the company expects will ultimately be 4,000 sending Internet signals to customers below.

Musk’s plan has already won the endorsement of FCC Chairman Ajit Pai, who praised it as a tool for extending high-speed Internet access to rural areas. But a rival of the company, OneWeb, argues that Musk’s plan is dangerous.

Quartz reports:

Both companies plan to invest billions in an unproven communications architecture: Rather than a dozen large, powerful satellites broadcasting to Earth from tens of thousands of kilometers away, they will utilize thousands of comparatively small satellites, less than 1,500 kilometers above the planet. The swarming satellites will be able to provide constant, low-latency internet connections to users—if their designers can handle the tricky task of managing the satellites and the signals passed between them and with ground stations below.

This idea had been tried in the 1990s, to resounding failure. Now a new generation of space entrepreneurs thinks that increasingly small and powerful electronics, lower launch costs and growing demand for internet access make a better business case.

Greg Wyler, a telecom entrepreneur who founded another successful satellite company called O3b, is the executive behind OneWeb, which owns key spectrum rights and has the backing of such diverse figures as Richard Branson, Masayoshi Son and Airbus. Wyler and Musk once contemplated working together, but their partnership fell apart and they became competitors.

Musk has won this round by launching the first demonstration satellites and will have a significant advantage if he can get a network up and running first.

But there are concerns about any of these proposals that more low-orbit satellites will mean more risk of space collisions.