Design and development of prototype universal extruding subterrene penetrators

The design features and development tests of electrically heated rock-melting universal extruding SUBTERRENE prototype penetrators are described. Engineering drawings of the successful 58-mm-(2.3-in.)-diam refractory metal penetrator system are presented. These prototype penetrators have melted holes in laboratory samples of basalt, granite, and low-density tuff. The rock-melt debris, or cuttings, can be extruded in a variety of forms including glass rods, glass pellets, and rock wool. These cuttings are removed by the coolant through the annular stem in a manner similar to that used in rotary drilling technology. /AUTHOR/