Aerodynamics and Impact Simulation of an Air-Dropped Ice Penetrator

Abstract

In order to investigate movement of the Ross Ice Shelf in Antarctica, an air-dropped ice penetrator will be employed. Dropping a seismic probe from a helicopter offers several advantages over sending out a conventional crewed mission, such as reduced transit time and access to hard-to-reach locations. However, a new set of problems to be solved arises. The penetrator must fall fast enough to guarantee rigid coupling to the ice shelf, but slow enough to avoid damaging internal components. Aerodynamic analysis is used to select a penetrator geometry, and to suggest a drop altitude of at least 5000 ft (1524 m). Detailed simulations of the impact reveal shock loads up to 566 G from a drop velocity of 42.5 m/s. Finally, the effects of steady wind are analyzed, and point to a maximum recommended wind speed of 7.5 m/s for drop operations.