China's DSLWP-A1/A2 Moon Data Transmission

China is planning to launch the Chang’e 4 lander and rover which is slated to land on the far side of the moon in December. The lander configuration will use a relay satellite for a control and data link with Earth.

Also aboard this flight will be a pair of microsatellites, DSLWP-A1 and DSLWP-A2, which will test low-frequency radio astronomy and space-based interferometry. These two lunar orbiting satellites developed by students at the Harbin Institute of Technology will include educational and amateur radio payloads (but not a transponder).

The Amateur Radio payload on DSLWP-A1 will provide a telecommand uplink and a telemetry and digital image downlink. Radio amateurs will be able to transmit commands that allow them to send commands to take and download an image.

The IARU has coordinated downlinks on 435.425 MHz and 436.425 MHz for A1.
Downlinks have been coordinated for A2 are 435.400 MHz and 436.400 MHz using 10K0F1DCN or 10K0F1DEN (10-kHz wide FM single-channel data) 250 bps GMSK with concatenated codes or JT65B.

A1 and A2 will be deployed into a 200 × 9,000 kilometre lunar orbit. The 50 × 50 × 40 centimeter spacecrafts each weigh about 45 kilograms and are three-axis stabilized. Two linear polarization antennas are mounted along and normal to the flight direction.

The satellites will use the moon to shield them from radio emissions from Earth for the long wavelength space-based interferometry experiments.

The launch is anticipated for May or June on a CZ-4C vehicle, putting the satellites’ deployment about 6 months ahead of the launch of the Chang’e 4 lander and rover.