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by weregiraffe 1030 days ago
Huh? Why would the satellites go off? The Starlink satellites know they own location, so they most likely have a list of cells they are allowed to serve. It's a lot harder to hack a satellite in orbit than a terminal you have physical access to.
1 comments

Well… no actually. Many satellites are “bent pipes”, and do no signal authentication. They just transpond and send the data back down. If you can get the uplink to hear you, you can use it. The problem is uplink may not always be listening in your direction.

It’s actually really easy to jam or pirate many satellites for this reason. I’m unsure if spacex has more auth than the industry standard.

Source: I used to geolocate jammers and pirates.

Starlink is unique in being a LEO massive constellation using phased arrays and thus afaik cannot work like that. The terminal and satellites must work in conjunction to steer the beam electronically at a pretty fast rate, they're only ~550km away at a relative velocity of 7-someodd km/s. Cells are quite small, beam spots even smaller, and terminals must both track a given sat and jump between multiple ones.

Yes, all indications are that SpaceX auth is also very modern and very good, but the very nature of the system means they have to have quite precise location information on both sides. The satellites will simply not transmit where it's not permitted by regulators, and can do that with high resolution because they simply physically cannot usefully see very big circles. That's exactly why thousands and thousands of satellites are needed.

In another comment you mentioned "if there's any beam shaping" which seems to indicate you really haven't ever taken any real look at Starlink? It's nothing like an old HEO sat system.

> seems to indicate you really haven't ever taken any real look at Starlink? It's nothing like an old HEO sat system.

I haven’t! I enjoyed being enlightened by your comment though.

Here's a live map of the constellation that also shows ground stations: https://satellitemap.space/

SpaceX has been developing sat to sat links, but in the current system a majority of traffic just goes up and down like a bent pipe. However because of the speed the sats move the system needs to know the location of all endpoints in real time. A given sat is only visible to a base station for something like 90 seconds. So it's very different from traditional GEO services, or even MEO services like Iridium et all for that matter.

It's the ground side, the user endpoints and downlink stations (the latter Starlink can do without in some places due to the laser links) though that need approval to transmit from country regulators.

The sats themselves are regulated by the launching country, the US only.

I'd expect that since Starlink has to be a bit more involved in the communication (particularly for determining need for packet routing over the laser interconnects between satellites), they might not be bent pipes.

Plus, with things like updating the constellation, which likely is a significant security concern, they would probably be relying on some sort of geofencing.