LoRa to the Moon and back: Messages bounced off lunar surface using off-the-shelf hardware

... and a damn big radio telescope


A team of scientists has managed to bounce a LoRa message off the Moon, setting an impressive record of 730,360km for the furthest distance such a data message has travelled.

While much of the technology was off-the-shelf (Semtech's LR1110 RF transceiver chip was used) the signal was amplified to 350w using the 25-metre dish of the Dwingeloo Radio Observatory in the Netherlands. The same dish and chip was used to receive the signal on its return from the Moon, just under two and a half seconds later.

The team consisted of Thomas Telkamp, CTO of Lacuna Space and Frank Zeppenfeldt, a 20-year ESA veteran working in the field of IoT and Smallsats. For CAMRAS (CA Muller Radio Astronomy Station), the foundation behind the telescope, were Jan van Muijlwijk and Tammo Jan Dijkema.

The Register spoke to Telkamp, who told us the project "was a thing that was on my to do list for a long time."

"We figured out 'We should be able to do this'," he added, "and then it was a matter of finding all the equipment and people to execute it".

"And, ultimately, we needed a big telescope."

Although bouncing signals off the Moon is hardly a new thing (and reflectors left on the lunar surface by the Apollo and Lunokhod programs have enabled scientists to use laser ranging to get a precise measurement of the distance between the Earth and Moon) doing it with LoRa and off-the-shelf components: "was really the challenge," said Telkamp.

"And because we only had one telescope available it needed to be a very short message," he told us, "because we needed to receive our own message.

"So we transmit, immediately switch to the receive mode and receive our own message back. And that is for me the most hilarious part of it... this whole message for a short term of time is actually in space as a whole. At some point you have transmitted the message, you're going to receive it so you're waiting for your own message to be bounced back to you."

As well as the technology demonstration of actually bouncing a message off the Moon, some bonus science was accomplished during the experiment. "Because the radio signals were slightly shifted," Telkamp explained, "and we could compare them to the theoretical position of the Moon."

The Moon, of course, moved during the transmission of the message.

"And with that," he added, "we basically could make a radar image of the Moon, which was completely not the purpose of the whole experiment but just as a side effect.

"We could actually see the sphere of the Moon simply by looking at the message that was echoed back to us."

The experiment is undoubtedly neat. (Nicolas Sornin, co-inventor of LoRa, gave it a thumbs-up, declaring himself impressed with the quality of the data, and said: "This is a fantastic experiment. I had never dreamed that one day a LoRa message would travel all the way to the Moon and back.") The practical applications, meanwhile, are of interest to space agencies.

"This is not 5G, high bandwidth stuff," Telkamp told us, "this is low bandwidth stuff, but also low power, low cost and very very small."

So think more messaging from an astronaut or telemetry from a probe than full-on high definition video.

As for next steps, getting an additional radio telescope would save having to quickly reconfigure a single dish from transmit to receive. And perhaps farther afield? "It would be nice to do this with Venus," Telkamp mused, before laughing: "But that's a few orders of magnitude more difficult." ®

Similar topics

Broader topics


Other stories you might like

  • India reveals home-grown server that won't worry the leading edge

    And a National Blockchain Strategy that calls for gov to host BaaS

    India's government has revealed a home-grown server design that is unlikely to threaten the pacesetters of high tech, but (it hopes) will attract domestic buyers and manufacturers and help to kickstart the nation's hardware industry.

    The "Rudra" design is a two-socket server that can run Intel's Cascade Lake Xeons. The machines are offered in 1U or 2U form factors, each at half-width. A pair of GPUs can be equipped, as can DDR4 RAM.

    Cascade Lake emerged in 2019 and has since been superseded by the Ice Lake architecture launched in April 2021. Indian authorities know Rudra is off the pace, and said a new design capable of supporting four GPUs is already in the works with a reveal planned for June 2022.

    Continue reading
  • Prisons transcribe private phone calls with inmates using speech-to-text AI

    Plus: A drug designed by machine learning algorithms to treat liver disease reaches human clinical trials and more

    In brief Prisons around the US are installing AI speech-to-text models to automatically transcribe conversations with inmates during their phone calls.

    A series of contracts and emails from eight different states revealed how Verus, an AI application developed by LEO Technologies and based on a speech-to-text system offered by Amazon, was used to eavesdrop on prisoners’ phone calls.

    In a sales pitch, LEO’s CEO James Sexton told officials working for a jail in Cook County, Illinois, that one of its customers in Calhoun County, Alabama, uses the software to protect prisons from getting sued, according to an investigation by the Thomson Reuters Foundation.

    Continue reading
  • Battlefield 2042: Please don't be the death knell of the franchise, please don't be the death knell of the franchise

    Another terrible launch, but DICE is already working on improvements

    The RPG Greetings, traveller, and welcome back to The Register Plays Games, our monthly gaming column. Since the last edition on New World, we hit level cap and the "endgame". Around this time, item duping exploits became rife and every attempt Amazon Games made to fix it just broke something else. The post-level 60 "watermark" system for gear drops is also infuriating and tedious, but not something we were able to address in the column. So bear these things in mind if you were ever tempted. On that note, it's time to look at another newly released shit show – Battlefield 2042.

    I wanted to love Battlefield 2042, I really did. After the bum note of the first-person shooter (FPS) franchise's return to Second World War theatres with Battlefield V (2018), I stupidly assumed the next entry from EA-owned Swedish developer DICE would be a return to form. I was wrong.

    The multiplayer military FPS market is dominated by two forces: Activision's Call of Duty (COD) series and EA's Battlefield. Fans of each franchise are loyal to the point of zealotry with little crossover between player bases. Here's where I stand: COD jumped the shark with Modern Warfare 2 in 2009. It's flip-flopped from WW2 to present-day combat and back again, tried sci-fi, and even the Battle Royale trend with the free-to-play Call of Duty: Warzone (2020), which has been thoroughly ruined by hackers and developer inaction.

    Continue reading

Biting the hand that feeds IT © 1998–2021