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An open-source 240-antenna array to bounce signals off the Moon

258 points by hillcrestenigma

by jacquesm

3 subcomments

I don't think you should call something 'open source' until you've released the source, but other than that this is an extremely impressive project. HAM's have been doing EME since forever (https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Ear... ), it is a very neat trick.
It almost looks as if the EME bounce capability of this antenna is a fig leaf or an afterthought, my own 'applications' list would be a lot of things, but not that.

by infinitewars

4 subcomments

Wild hardware flex for a garage project. Reverse-engineering the Pi 5's MIPI to push 5.6 Gbps from custom MASH sigma-delta ADCs to a Lattice ECP5 FPGA to the Raspberry Pi is serious engineering. The idea that the RF receiver looks like a "camera" to the Pi while the transmitter is a "display" is super creative. Getting a 1.5 kW, 240-antenna EME array for $2,499 is actually cheap for something like this.
Their standalone 4-antenna tiles (https://moonrf.com/updates/) show off some killer apps, like 30 fps spatial RF visualization and NEON-optimized drone video interception.
I'm rolling my eyes at the "Agentic Transceiver" part, though. It is highly doubtful that an onboard AI casually writes, debugs, and compiles a real-time C app with analog video color sync recovery and decode in ten minutes.

by drmpeg

1 subcomments

Previous post.
https://news.ycombinator.com/item?id=45790672

by lutusp

0 subcomment

For context, the same phased-array transceiver technology is used in Starlink terminals, some of which have 1,280 active elements. Such a terminal can require as much as 150W to function.
It's also why pictures of modern naval vessels show flat panels instead of rotating parabolic antennas as in past decades. The panels contain advanced phased-array radars.

by royskee

3 subcomments

Every time I hear about Earth-Moon-Earth moonbounce comms, I think of this classic reddit comment: https://www.reddit.com/r/amateurradio/comments/8lpk45/commen...

by wolvoleo

1 subcomments

Pretty cool. And expensive. It's pretty amazing how starlink sells basically this for $200. Pretty sure they subsidize it.
Ps you don't really need this. A phased array is great for communicating with or tracking fast moving objects. For something as slow as the moon a simple parabolic dish, either manually aimed or with an az/el motor will be more cost-effective. Motors get expensive too with wind and rain and longevity (moving around 24/7) but hams don't moonbounce constantly.
Starlink sats move really quickly through the night sky and it tracks multiple so you don't have interruptions this is why for that purpose a phased array is great. For incidental ham use to the moon it's very interesting tech but not exactly necessary.

by kmbfjr

0 subcomment

EME has been made a bit more affordable and effective by weak signal modes and DSP.
It used to require very high power, expensive transmission lines, preamps and monstrous arrays of Yagis. Now with JT65x, and SDRs, you can use cheaper coax to get transmit power to the antenna eating that loss with more RF, and put SDRs for RX at the array. People running digital modes are getting away with needing less gain.
5650MHz is the only place to do it with this thing. Might want to break out a calculator before the credit card because path loss has to be more than 285dB. But if you can swing it, might want to buy two so you have someone to talk to. I have not heard anyone using 5650.

by mschuster91

1 subcomments

> The target launch price is probably ~$399 (dependent on the tariff landscape over the next month). For that you get the QuadRF tile, an included Raspberry Pi 5, the custom case, tripod, USB-C power supply, cables, and a pre-loaded SD card with a ton of cool SDR applications.
Meanwhile... the RPi alone will probably make up 299 dollars of that price tag [1].
It is not a good time to design hardware that needs RAM. Arrest and imprison Sam Altman.
[1] https://www.jeffgeerling.com/blog/2026/dram-pricing-is-killi...

by dtj1123

0 subcomment

This is brilliant, but on a less than brilliant internet connection like mine the site images are loading at a snails pace. Maybe use WebP rather than png?

by O5vYtytb

2 subcomments

> Power Supply: 12 V DC (≈1.5 kW peak)
That's a lot of juice for 12VDC

by tamimio

0 subcomment

Looks interesting, I have many great ideas to test them out with this! I wonder if I can use my SDR with it.

by ardline

0 subcomment

Solid work. The edge cases in section 2 are the ones that always bite you.

by manuelmenzella

1 subcomments

It says it’s open source but I can’t find a link to a repository. Am I missing something?

by diimdeep

2 subcomments

Cool, how full array compares to the single antenna placed on Starlink satellite ?

by thomashabets2

3 subcomments

"Country restrictions apply". Which countries?

by ck2

1 subcomments

can amateurs bounce photons off the mirrors left there by Apollo 17 yet
or does it still need industrial grade lasers?