China's first lunar probe that soft landed on the surface of the Moon was Chang'e-3. The rover that was part of this mission carried an X-ray spectrometer that was attached to the end of a robotic arm, so that the X-ray spectrometer could be used to measure the mineral content of rocks on the lunar surface. This article describes a laboratory experiment that was carried out in order to calibrate the X-ray spectrometer used in the Chang'e-3 mission so that accurate measurements could be acquired, helping to advance this effort.

http://www.raa-journal.org/raa/index.php/raa/article/view/1946