Alternatively, is there a wavelength of light to which water is completely transparent? Can we shoot lasers of that frequency through open water instead of through cables?
Maybe something that could be mounted on blue whales?
Normally in imaging, you first need to get the satellite over the location you want to image, at the right time - then let it orbit over a downlink location.
There are companies making a lot of money by having downlink capability in useful places (eg: near the poles) - combined with a fat pipe to the Internet.
With Starshield, the satellites talk to each other over laser - so the satellite doesn't have to wait to travel to a downlink location - just relay to of that is already there.
So for certain special cases it can help - but I think you'll find a cable stuffed with multimodal fiber had vastly more bandwidth.
Space lasers probably don't do multiple wavelengths, and aiming a lot of laser transceivers is going to be challenging.
> Alternatively, is there a wavelength of light to which water is completely transparent? Can we shoot lasers of that frequency through open water instead of through cables?
Even if you could, that's only going to work for short hops, long distance fiber includes repeaters every so often (50-100 km) to deal with loss, it would be tricky to build those under the sea ... and you need to power them, which means a cable, might as well include fiber with your power cable.
The cables can go the entire distance between the data centers. The satellites probably connect to their closest neighbors, and any long distance transmission would have to make multiple hops, and share the bandwidth with everything else in the system going through the same nodes.
Since there are hundreds of undersea cables, with a dozen fiber pairs or so each, the cable system has several orders of magnitude greater throughput compared to the current constellation of satellites.
Of course, it depends on the altitude of the satellite but speed of light in a fiber optic is only ~2/3rds of speed of light in a vacuum so you can afford some detour
That made me wonder: Why can't we use vacuum cables?
(the sort of questions I should probably be bothering an LLM with.. someone should make a LMGPTTFY)
Hollow-core fiber is basically this!
> LMGPTTFY
"let me go prompt that for you" or "let me GPT that for you"?
yes
But otherwise chains of microwave links does get much closer to c in applications where you want absolute lowest latency (or much more commonly, when digging a fiber line is too expensive)
(Irritiating, but not as bad as those who insist on having milli-bit speeds I grant you).
bandwidth would indeed be worse
The high capacity in submarine fiber is achieved through DWDM and coherent modulation 100Gbps+ transceivers, not massive parallelism in fiber use.
I'd be astonished if it runs into capacity problems with an ultimate upgrade capacity of being able to run at least 20 different 200 or 400 Gbps circuits per fiber pair if appropriately costly DWDM terminals are installed at each end of dark fiber. Not even if all the tiny towns and cities that it hits were to magically quadruple in population.