China’s Chang’e-4 lander as viewed by Yutu-2 rover.

International experiments carried onboard China’s Chang’e-4 farside mission are gathering good data, report their principal investigators.

Germany’s scientific payload is a Lunar Lander Neutron and Dosimetry instrument, developed by Kiel University. Credit: Kiel project manager, Jia Yu

The Lunar Lander Neutrons & Dosimetry experiment (LND) is part of the Chang’e-4 lander payload.

The LND instrument has two major science objectives: 1) dosimetry for human exploration of the Moon and 2) contribute to heliospheric science as an additional measuring point

“LND is working fine,” reports Robert Wimmer-Schweingruber of the Institut fuer Experimentelle und Angewandte Physik, University of Kiel in Germany. “We were turned on for the third lunar day last Friday and have now received our data or the previous two lunar days,” he told Inside Outer Space. “We see some variations in the dose rate with time which we need to understand before we start publishing the data.”

The LND device is designed to gauge radiation on the Moon, mainly for future human missions. It will also measure the water content underneath the lander.

Advanced Small Analyzer for Neutrals (ASAN) device.
Credit: Swedish Institute of Space Physics


Working flawlessly

Meanwhile, Sweden’s Advanced Small Analyzer for Neutrals (ASAN) carried by the Yutu-2 rover is also gathering data.

“Yes, we are doing fine! ASAN is operated typically twice per lunar day,” reports Martin Wieser of the Swedish Institute of Space Physics in Kiruna, Sweden.



“ASAN works flawlessly and the data is good. People are working on the first papers,” Wieser told Inside Outer Space.

Energetic sensor

ASAN was built in collaboration with the Chinese National Space Science Center (NSSC). It is the first time an energetic neutral atom sensor is deployed on the lunar surface. From a vantage point of only a few decimeters above the regolith surface, ASAN is geared to measure energy spectra of energetic neutral atoms originating from reflected solar wind ions under different solar wind illumination conditions.

Image of China’s Yutu-2 lunar rover taken by Chang’e-4 lander.

ASAN is mounted on the Yutu-2 rover making it possible to perform measurements at different locations. The measurements could shed light on the processes responsible for the formation of water on the Moon.

Chang’e-4 landed within the South Pole-Aitken (SPA) Basin, the largest and deepest basin in the solar system. The January 3 touchdown was in Von Kármán crater, a 110 miles (186-kilometers) wide region.

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