Does HackRF require soldering an RF shield to it? Apparently it comes without it by default.
No, but you can add it if you want a lower noise floor.
Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
21–30 of 114 posts
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#22How likely is the possibility of sdr freeing us from wifi chips or cell modems that need proprietary firmware?
The latter already exists, at least for LTE.
Well, SDR-based clients that you could package in a smartphone form factor. They're fairly power-hungry, though.
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#23Earlier quoted context omitted.
Amateur astronomers are very good at spotting national security payloads after launch. https://www.theatlantic.com/technology/archive/2016/06/mappi...
Yup. Easy to do for most adversary nation-states as well, but the NRO still doesn't allow the SpaceX livestream to follow stage 2.
Maybe it's possible to detect radio echoes off the rocket exhaust trail (passively) like it is possible to do with meteors [0][1] and roughly tell where the second stage is (just for the sake of doing it this way).
[0] https://www.electronics-notes.com/articles/antennas-propagat...
[1] https://en.wikipedia.org/wiki/Meteor_burst_communications
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#24Earlier quoted context omitted.
Amateur astronomers are very good at spotting national security payloads after launch. https://www.theatlantic.com/technology/archive/2016/06/mappi...
Yup. Easy to do for most adversary nation-states as well, but the NRO still doesn't allow the SpaceX livestream to follow stage 2.
Yeah, over-classification is definitely a thing. I suspect they don't want close-up video imagery of the payloads out there, either.
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#25I feel that this data is trade secret - why it is not encrypted?
I imagine it adds latency, which at the very least means more data is lost in case of accident, which can make it harder to know what went wrong. It also adds an additional failure point, as a single bit error during encryption can scramble an entire data packet or worse, rather than just invalidating a single sensor reading.
You can do this with FPGAs in real-time.
https://www.google.com/search?q=fpga+encryption+serial+data+...
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#26Earlier quoted context omitted.
> This doesn't strike me as particularly sensitive. I'm no rocket scientist but I would have thought you'd want to encrypt and sign everything... by default. Otherwise how do you stop spoofing as well?
Encryption takes time, and energy. I suspect they are trying to avoid adding latency to anything that’s not super sensitive.
Those final gasps of data while a vehicle is breaking up could be critical for understanding what went wrong with it. I can definitely see how missing out on the final milliseconds of telemetry because some encryption buffer wasn't full enough to trigger a frame or something would be unacceptable.
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#27This is something I’ve always thought about doing, but lack the in-depth RF/demodulation knowledge to undertake. Glad to see the SDR community is already on top of it!
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#28How likely is the possibility of sdr freeing us from wifi chips or cell modems that need proprietary firmware?
It would be cool but I don't see it happening any time soon. Plenty of demos have been created, but the ASICs that the SDR would be competing with are much more efficient at doing their particular job, and they're very cheap.
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#29Earlier quoted context omitted.
Amateur astronomers are very good at spotting national security payloads after launch. https://www.theatlantic.com/technology/archive/2016/06/mappi...
And if amateur astronomers can do it, a well-funded national space agency can do it even better. I'm 100% sure that any launch is picked up via radar and sattelites and the like when they happen, and various properties extracted and extrapolated to determine their target orbit. That said, I wouldn't be surprised if some known launches also contained some unknown payloads. Stealth technology on a satellite would proba…
> Stealth technology on a satellite would probably thwart detection in space well enough.
Stealth is great for radar, but even the B-2 can be spotted pretty easily via the Mk 1 eyeball. Satellites also have to have radiators, which limits what you can manage.
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#30Some sleuths repaired/decoded a corrupted video file from (the first?) splashdown of a Falcon 9 in the ocean a few years ago [0], so maybe someone is able to tease out some information from the recorded binary data as well? They only searched for obvious string data so far. It's a different beast of course, as the structure and meaning of the data is basically unknown in contrast to the known format of a video file.…
I'm kinda hoping they'll publish some specs about at least part of their transmission data, I mean given that it's not encrypted either means it's not critical, or encryption is too costly. I can imagine that commands the other way do have some kind of encryption.
I'd assume so. It's standard practice with space hardware to keep the downlink unencrypted, and secure just the command channel. Saves on complexity and power use (the latter matters a lot for satellites).