LO-94 Amateur Radio in Lunar Orbit

Longjiang-2 / LO-94 in Lunar Orbit

Longjiang-2 / LO-94 in Lunar Orbit

Nature carries an article about the spacecraft Longjiang-2 / Lunar-OSCAR 94 (LO-94), built by students at the Harbin Institute of Technology, that carried the first Amateur Radio communication system to operate in lunar orbit.

As a part of China’s Chang’e-4 lunar far side mission, two lunar microsatellites for low frequency radio astronomy, amateur radio and education, Longjiang-1 and Longjiang-2, were launched as secondary payloads on 20 May 2018 together with the Queqiao L2 relay satellite.

On 25 May, 2018, Longjiang-2 successfully inserted itself into a lunar elliptical orbit of 357 km × 13,704 km, and became the smallest spacecraft which entered lunar orbit with its own propulsion system. The satellite carried the first amateur radio communication system operating in lunar orbit, which is a VHF/UHF software defined radio (SDR) designed for operation with small ground stations.

This article describes and evaluates the design of the VHF/UHF radio and the waveforms used. Flight results of the VHF/UHF radio are also presented, including operation of the radio, performance analysis of downlink signals and the first lunar orbit UHF very-long-baseline interferometry (VLBI) experiment.

Read the article at https://www.nature.com/articles/s41467-020-17272-8

Cartoon movie – Longjiang-2 / LO-94: Journey to the Moon
https://amsat-uk.org/2020/06/06/longjiang-2-lo-94-journey-to-the-moon/

Longjiang-2 / LO-94: Journey to the Moon

Longjiang-2 / LO-94 in Lunar Orbit

Longjiang-2 / LO-94 in Lunar Orbit

A cartoon movie has been made that tells the story of the student-built spacecraft Longjiang-2 / Lunar-OSCAR-94 which went into lunar orbit and transmitted SSDV images back to radio amateurs on Earth.

SSDV image of Moon and Earth taken by LO-94 (Longjiang-2) - Credit Cees Bassa

SSDV image of Moon and Earth taken by LO-94 (Longjiang-2) – Credit Cees Bassa

Longjiang-2 / LO-94, developed by students and researchers at the Harbin Institute of Technology, is the world’s smallest spacecraft to enter lunar orbit independently. It was launched on May 20, 2018 and radio amateurs tracked its progress as it traveled towards the Moon and successfully entered lunar orbit.

The spacecraft transmitted signals back to Earth on 435.400 and 436.400 MHz. The amateur radio mode SSDV (Slow Scan Digital Video) was used to send back pictures of the Moon and WSJT JT4G was used for messages.

Two VHF/UHF SDR transceivers onboard were used to provide the beacon, telemetry, telecommand, digital image downlink and a GMSK-JT4 repeater, transmitting power was about 2 watts.

Watch Longjiang-2: Journey to the Moon

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