The race is on to build a new kind of internet. A host of companies and billions of dollars are in play, with the ultimate goal of ringing the planet with satellites that will allow anyone, anywhere, to get online at broadband speeds.
Presently, satellite internet relies on spacecraft that are in geosynchronous orbit, travelling at the same speed as Earth rotates. But while this ensures the satellites are always in the same spot above Earth, it means there is a large time lag in the service, as radio waves take a quarter of a second to make the round trip up to a geosynchronous satellite and back. Added to the time for the other trips your data must take across the rest of the internet, the lag becomes unworkable for real-time applications like video or voice chat (see diagram).
To speed up the service, firms are looking at using satellites closer to Earth. This month, Virgin Galactic and chip-maker Qualcomm announced their backing of a venture called OneWeb. This plans to put 648 satellites in orbit about 1200 kilometres above Earth's surface, where the round trip time for radio waves is just a few thousands of a second, fine for any online application. SpaceX immediately announced its own plan to do the same, building and launching 4000 satellites to a similar altitude. That would more than double the number of satellites in orbit.
To read more, click here.