An open-source 240-antenna array to bounce signals off the Moon
moonrf.com138 points by hillcrestenigma 9 hours ago
138 points by hillcrestenigma 9 hours ago
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.
> Getting a 1.5 kW, 240-antenna EME array
It says 1W TX power per antenna. So the 240 antenna array which draws 1500W has a transmit power of 240W.
EIRP. There's some gain involved.
I think they're claiming the actual transmit power is 240W (23.8 dBW), and the EIRP is 63.1 dBW.
I am sort of skeptical of the claimed gain... even at 6GHz, you need a 2-meter parabolic reflector to get 40dB, the array is 1/10th that diameter. EDIT: Ignore this second paragraph I misread the spec page.
I'm struggling to understand the signal chain or antenna architecture here. If those two MAX chips are 2829s this would be 2x2 mimo per tile but I'm not super familiar with that product line and the PCB layout looks like a 4x4 setup.
And yeah, the agentic stuff is dumb, I've played a ton with doing low level SDR work on Opus 4.6 and it's truly ass.
Also, the "can't radar, plz don't ITAR" is horseshit. Some basic fw tweaks and you could get this to be, at the very least, a sweet FMCW setup.
MAX2850/2851 4x4. Also, large radar stuff is more nuanced than "just some fw tweaks" as you claim. Same as Facebook is not just some PHP scripts...
It says it’s open source but I can’t find a link to a repository. Am I missing something?
Previous post.
looks like there have been updates since then: https://moonrf.com/updates/
"Country restrictions apply". Which countries?
> 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...
Cool, how full array compares to the single antenna placed on Starlink satellite ?
How would that be a useful comparison? Aren't the use-cases too different?
Not only is the moon >100x farther away (even accounting for near-horizon satellite angles), but you're also trying to bounce a signal off it as a passive reflector, which is harder than just transmitting something an active lunar receiver could detect and re-transmit back.