We use data from the Lunar Prospector Neutron Spectrometer to make the second space-based measurement of the free neutron lifetime finding $tau_n=887 pm 14_text{stat}{:^{+7}_{-3:text{syst}}}$ s, which is within 1$sigma$ of the accepted value. This measurement expands the range of planetary bodies where the neutron lifetime has been quantified from space, and by extending the modeling to account for non-uniform elemental composition, we mitigated a significant source of systematic uncertainty on the previous space-based lifetime measurement. This modeling moves space-based neutron lifetime measurement towards the ultimate goal of reducing the magnitude of the systematics on a future space-measurement to the level of those seen in laboratory-based experiments.
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