

How do astronauts connect to the Internet in space? - ForHackernews
http://www.theatlantic.com/technology/archive/2015/06/the-internet-in-space-slow-dial-up-lasers-satellites/395618/?single_page=true

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ceejayoz
I'd really like to know if the ISS wifi has a password.

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ttepasse
ESA astronaut Alexander Gertz gave a talk* some month ago. About the wifi he
said that it is good quality in the central spine of the ISS but the outlying
modules have very bad reception. Living in big metal cans seems to have that
effect. Nothing about the password though.

* [https://www.youtube.com/watch?v=l8tTRgTqLn8](https://www.youtube.com/watch?v=l8tTRgTqLn8) (german)

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tgb
So it's exactly as good or bad as ground systems using a geosynchronous
satellite for internet? (Wikipedia [1] says that geostationary satellites are
the norm for satellite internet.)

[1]
[https://en.wikipedia.org/wiki/Satellite_Internet_access](https://en.wikipedia.org/wiki/Satellite_Internet_access)

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lmm
I don't understand. It sounds like they don't have bandwidth problems, only
latency problems. But lasers travel at the speed of light just like radios;
switching to a laser approach isn't going to reduce latency any.

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helicon
I took it to mean the laser would be based on the station and so could
transmit directly to a ground station cutting out the extra 22,000 mile extra
hop to the geosync satellite?

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gus_massa
This image of the satelitte orbits makes the comparison easier:
[https://en.wikipedia.org/wiki/Geostationary_orbit#/media/Fil...](https://en.wikipedia.org/wiki/Geostationary_orbit#/media/File:Comparison_satellite_navigation_orbits.svg)

The geosync satellites are very high, 5.6 Earth radius above the Earth
surface. (The radius of the orbit is 6.6 Earth radius.) And you have to
multiply it by 2 because the signal has to go from the ISS to the satellite
and then to Earth.

The ISS is only 0.06 Earth radius above the Earth surface approximately. So in
this case, most of the latency will come from horizontal travel (and the
latency of the usual congestion in the net).

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tzakrajs
So your critical ISS controls share a network with internet browsing
endpoints. Nice!

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tzakrajs
Talk about one helluva beachhead.

