Lunar Atmospheric Composition Experiment

[3] The experiment could detect ions of 28 and 64 atomic mass units at the same time, enabling the simultaneous measurement of carbon monoxide and sulphur dioxide.

The entrance aperture was deployed upwards to measure the downward flux of gases at the lunar surface.

[2] At sunrise, it was found that heating of the experiment site and LACE's instruments resulted in high rates of outgassing.

[2] The experiment positively identified that the tenuous lunar atmosphere consisted of helium, neon and argon.

As night transitions into day, this frozen argon becomes mobile and migrates ahead of, and in tandem with, the sunrise terminator.

[4] Since the source of 40Ar was likely radioactive decay of potassium (40K), its presence detected by LACE provided evidence of a true native lunar gas.

[4] This conclusion was reached due to the fact that, unlike argon, the detection of these contaminants rose sharply contemporaneously with the local sunrise, rather than leading it.

[4] During LACE's tenth lunar month of operation, the experiment developed a problem with the instrument's high-voltage section.