Researchers at the Open University have begun a test campaign to extract and detect volatiles embedded in frozen lunar regolith simulants.
This is in support of the Volatiles Analyser, a miniature ion trap mass spectrometer that is currently in development.
Two series of experiments are being performed for this study.
The first, completed at the end of 2017, examined the extent to which volatiles, in this case water, embedded in the regolith simulant NU-LHT-2M are lost when brought to conditions simulating the lunar environment.
The regolith samples, doped with water contents of around 1, 5 and 10% by mass, were cooled to -150℃ in a dry nitrogen atmosphere in a vacuum chamber, which was then evacuated to a pressure of roughly 2 x 10-5mbar.
These tests were successful, with very little (<0.6%) water being lost when the sample is at held at -150C.
The second series, currently underway, will extract the water using a custom-made thermal probe, shown below, which can reach temperatures of over 160℃.
This can be manually lowered into the regolith, mimicking the action of the Volatiles Sampler’s heating rod.
The extracted water will be measured using a mass spectrometer.
The next step will be to use this system for characterising the breadboard Volatiles Analyser, prior to its integration with the Volatiles Sampler.