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Comment by syx | Hacker News Reader

> The prevailing wisdom is that hacking this kit would be prohibitively expensive due to the high cost of ground stations that communicate with the orbital birds, and that such hardware benefited from security by obscurity

I can really relate to this a lot. I've recently purchased a Flipper Zero and oh my god, so much tech is exposed based on NFC and Sub-GHz protocols. Many devices simply were not developed with security in mind because no one ever came up with such a tool to mess with. I wouldn't want people to mess with something floating on top of my house.

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> I wouldn't want people to mess with something floating on top of my house.

I understand the sentiment but it sounds like you may have a misunderstanding of how orbits work here. Even if a geosync satellite were positioned exactly above your house, nothing could ever make it "fall down" onto you. Anything that brought it closer to Earth would make it not a geosync satellite anymore, and I strongly doubt any geosync satellites have enough fuel left to de-orbit entirely (geosync is far away!)

For low-orbit satellites, sure, they can (and are designed to, eventually) de-orbit, but nobody can hit you with it. The debris breaks up in atmosphere and tiny pieces (with a few larger, actually dangerous ones) are scattered randomly over hundreds of square miles of what is most likely the Pacific Ocean.

while they don't have the fuel to deorbit themselves, they will eventually deorbit due to orbital decay.

Still, as you said, they won't fall straight down, and would probably burn up in the atmosphere regardless.

In the case of satellites in GEO that "eventually" is on the order of millions of years. For LEO it's a lot shorter obviously.

that's actually a good point, I didn't know orbital decay was so slow

Stupid question that I've always been curious about, driving around.

Can an old C-band (large) satellite dish be used for transmitting as well as receiving?

If so, would there be any benefit to doing so, versus smaller/K* dish dimensions?

Know this is a basic question, but RF isn't my field.

yes.

no advantage over the smaller more modern dishes, as the more modern dishes are made with better shape tolerances, so they can be smaller and still get the same amount of signal to the satellite.

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