Compaction by impact of unconsolidated lunar fines

An investigation was conducted concerning the macroscopic irreversible partial compaction of terrestrial or lunar fines. A sample material (70051), assumed to be typical of the fines in the unconsolidated material of the lunar regolith, was used in the experiments. Tests were also carried out with powdered Vacaville basalt. Release adiabate and Hugoniot measurements were conducted. It was found that the dynamic stresses required for irreversible compaction of lunar fines on the moon are significantly lower than the values inferred from the shock recovery experiments conducted by Christie et al. (1973).