This Is Elon Musk's Plan To Build A Space Internet

Illustration for article titled This Is Elon Musk's Plan To Build A Space Internet

Elon Musk doesn't dream small. That much is pretty clear from the hovering space rockets and the vacuum-tube mass transit system. But his latest brainwave, which involves covering both the Earth and Mars in a blanket of sweet, sweet internet, is downright ballsy.


Rumors of Elon Musk using SpaceX to put a constellation of internet-providing satellites into orbit aren't new — he's even confirmed it's something he's thinking about. But a Businessweek report has the full details. Some are expected, some a little less so.

First, the stuff we already knew, or thought we knew: Musk will be using a constellation of 'several hundred' (around 700) small satellites to give the planet global internet coverage. By using smaller satellites located close to the Earth, Musk thinks he can get the system into orbit cheaply, and also provide a faster satellite internet speed than what's currently available.

In fact, according to the Businessweek report, Musk isn't just hoping to connect the third world (a la Facebook and Google) with this project: the satellite system will rival existing fiber networks for speed.

Musk is thinking big in another way: Mars. He has made his ambition to establish a Martian colony pretty clear before, and, of course, you can't have a human colony without Netflix. More usefully, any new colony would need some kind of communications network, and the space entrepeneur thinks lots of satellites is the easiest way to do this.

Although there's no immediate timeline for when Elon is going to save you from Comcast, '50-60' employees will apparently start working on the project from the company's Seattle office, with that workforce growing dramatically over the next few years. [Businessweek]




Ok - so here's the skinny. Most geosynchronous communication satellite orbits are about 35785 km (give or take) above the earths surface. This is to maximize angles of transmission/reception and to maintain a static spot above the earths. Purely calculating off the speed of light, if the sending and receiving dish were EXACTLY under the satellite (which it never would be...but just a hypothetical best case scenario), your latency is 238ms (round trip signal time). Realistically, its more like 300-600ms. So - lets visit Elon's plan. Clearly he's planning for a LEO (low earth orbit) constellation of satellites. You're talking 200-500km above the earths surface (usually). Anything less than 300km is impractical due to atmospheric drag. Lets say he's going for 500km as that would minimize atmospheric drag but still keep it below the Van Allen radiation belt which means you don't have to harden the satellites quite as much (i.e. cheaper and easier to make...especially when you're making 700 of them...). Round trip time (best case scenario) is now 3.3ms...realsitically, more like 6-9ms. Even so, 6-9ms is perfectly reasonable for internet latency for just about anything. That being said, with LEO satellites, they won't be geostationary (they'll be traveling much faster around the planet to maintain orbit) - the real trick will be hopping the signal from one to another without dropping massive amounts of packets inbetween - that will be the real secret sauce.