Scientists have bounced a long-range message (LoRa) off the moon’s surface for the first time, indicating progress in the effort to make low-power communication with Earth possible in the future. The team of European scientists and licensed radio amateurs were able to use LoRa technology to fire a radio signal towards the moon through the proven Dwingeloo telescope operated by the CAMRAS foundation in the Netherlands. The feat set a new record of 730,360 km for the furthest distance a LoRa message has ever travelled. It was also the first time a data message was bounced using an off-the-shelf small RF (radio-frequency) chip. For a brief moment in time, the entire message “PI9CAM” (the call sign of the telescope) was in space on its way from Earth to the Moon and back.
This experiment also proved that LoRa technology, which is used for many IoT (Internet of things) applications, can cover such great distances and is possible to send and receive low-powered messages from the Moon. This technology has opened avenues for future lunar communications experimentation. The team consisted of Jan van Muijlwijk (CAMRAS), Tammo Jan Dijkema (CAMRAS), Thomas Telkamp (Lacuna Space) and Frank Zeppenfeldt (ESA).
Nicolas Sornin, co-inventor of LoRa, said: “This is a fantastic experiment. I had never dreamed that one day a LoRa message would travel to the moon and back. I am impressed by the quality of the data captured. This dataset is going to become a classic for radio communications and signal processing students. A big thumbs up to the team and CAMRAS foundation for making this possible.”
Thomas Telkamp, CTO of Lacuna Space, a global connectivity provider for the Internet of Things, said: “Seeing the message coming back from the Moon was exhilarating. From the round-trip time, we were able to calculate the distance to the moon, matching very well the predicted values of NASA's JPL Horizons ephemeris system. We even used the echo to see the shape of the moon, which we didn’t imagine we could.”
The Dwingeloo radio telescope, operated by the CAMRAS foundation, has a history of being used in amateur radio experiments and is now often used for moon bounces. This was the first time a data message was bounced using a small RF chip. This telescope was commissioned in 1956, and played an important role in the early exploration of the structure of the Milky Way using 21 cm hydrogen radiation.
With the help of LR1110 chip from Semtech, scientists also measured the round trip time of the message, and the frequency offset due to Doppler Effect caused by the relative motion of the Earth and the Moon. From the round trip time they calculated the distance to the moon. The distance and frequency offset matched very well with predicted values calculated using NASA’s JPL Horizons ephemeris system.
Scientists have also used an SDR (Software Defined Radio) to capture both the transmitted and received signal for further analysis. These measurements together with analysis notebooks will be published as open data. Given below is the Delay-Doppler plot of the received signal, essentially showing a radar image of the moon, an ultimate example of joint communications & sensing.
An in-depth overview of the entire experiment and results will be presented at The Things Conference on 27 – 28 January, 2022.
Click here to learn more about LoRa technology.
Click here to learn more about LR1110 chip.
Click here to learn more about the conference.
