The Lunar Atmosphere and Dust Environment Explorer (LADEE) entered lunar orbit 2013-10-06, and Chang'e 3 landed 69 days later producing dust and gas on 2013-12-14.
These were both quite interesting missions, the Chang'e-3 is the first lunar lander of the 21st century, operated an ultraviolet telescope on the moon, and deployed it's companion Yutu - the first lunar rover of the 21st century as well. LADEE made super-sensitive measurements of trace gas and tiny dust particles above the moon and tested an optical comms link between lunar orbit and Earth.
I remember reading about the timing of the two events - that Chang'e-3 was announced to be landing during LADEE's initial baseline calibration measurements, some of which are summarized in China's 1st Moon Lander May Cause Trouble for NASA Lunar Dust Mission, but I never heard what actually happened.
Wikipedia mentions it here but is inconclusive. So was the baseline calibration disrupted or did the landing provide additional science value? If the latter, please cite some example, thanks!
China's Chang'e 3 spacecraft, which was launched on December 1, 2013, and entered lunar orbit on December 6, (25) was expected to contaminate the tenuous lunar exosphere with both propellant from engine firings and lunar dust from the vehicle's landing. (26) While concern was expressed that this could disrupt LADEE's mission, (26) such as its baseline readings of the Moon's exosphere, it may instead provide additional science value since both the quantity and composition of the spacecraft's propulsion system exhaust are known. (27) Data from LADEE may be used to track the distribution and eventual dissipation of the exhaust and dust in the Moon's exosphere. (27)(28) It may also be possible to observe the migration of water, one component of the exhaust, giving insight on how it is transported and becomes trapped around the lunar poles. (29)