[stavros]

That's amazing, I'm having trouble believing that a mobile phone's antenna can talk to space, 500km away. Do you know what sort of bandwidth these will have?

[ianburrell]

The bandwidth will be small. I saw 2-5 Mbps for the whole cell covering a city. Devices will be limited to messages, small amounts of data, and voice.

[stavros]

That's still the difference between lost in the mountains and "my coordinates are X, Y".

[comboy]

But it's still a mobile phone transmission power (1W?) and then r^2. Distinguishing that from noise seems mind-boggling.

[dzhiurgis]

Really just makes one think what sort of capability military has.

[JaimeThompson]

Check out the Orion series of Sigint birds[1]

" The satellites have estimated mass close to 5,200 kg and very large (estimated 100 m diameter) radio reflecting dishes."

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

[RoddaWallPro]

But just to clarify, because I'm also having a hard time imagining this, an LTE antenna in a cell phone can beam data to a satellite and have it picked up? Even at whatever low kbps? That is insane to me!

[wmf]

Yes. It's been demonstrated a few times.

[lxgr]

There are IoT devices that can talk to geostationary satellites, and these are roughly 100 times further up (36000 km vs. 300-1000 for LEO)!

I have one that’s significantly smaller and lighter than a smartphone, antenna and all.

These satellites partially make up for the distance by deploying huge antennas, sometimes augmented by large reflector meshes that can only unfold in space.

[stavros]

Yeah, that's pretty crazy, I guess that's what GPS receivers do, in the end (though at pretty low bandwidths).