Low-density sabot stripper: A feasibility study

Abstract

We replaced the traditional steel-plate sabot stripper used in light-gas gun operations with a relatively thick layer of low-density material (<0.1 g/cm3), such as steel wool, crumpled Al-foil, or batting of glass-fiber thermal insulation. The objective was to decrease the shock stress of the impinging, plastic sabot petals, thus decreasing and possibly eliminating the production of sabot vapor and melt which typically plate out on the nominal target as soot deposits. Such deposits can be an unsightly nuisance to many, but they are intolerable to some, such as those conducting experiments into transparency issues of spacecraft windows and solar cells, or to those investigating impact-induced organic chemistry and its implications for the origins of life. Also, the particulates generated upon traditional sabot impact may be efficiently trapped at depth in these low-density materials, keeping them from impinging on the nominal target. A modest test program, consisting of a total of ten experiments was therefore conducted. All three test-media revealed much less target contamination. None of the targets, however, was totally free of contamination, and more systematic work is necessary to produce contamination-free targets. Notably, all targets were also free of the small-scale particle impacts resulting from sabot impact on steel strippers. Replacing steel strippers with low-density media is thus promising where soot deposits and small particle impacts on the nominal target are either a cosmetic nuisance or a major, possibly intolerable, detriment to an experiment's objectives.