A review of penetrator designs for contact studies of space objects

The paper provides a review of advanced equipment for contact studies of space objects - penetrators. A penetrator is a tool for acquisition of raw scientific data about physical and chemical composition of the soil during penetration into a planet down to the depth of several meters, and in some versions, subsequent transfer of the obtained material to Earth. The history of space penetrator evolution spans more than 30 years, and such penetrator designs are being developed by various space agencies in many countries, but at the moment there is still no precedent completed flight experiment. The designs considered in this review are in various stages of development ranging from concept proposals to full-scale experiments. This paper shows a great variety in the characteristics of such tools for studies of space bodies. The paper provides an analysis and classification of such designs, which may be useful for the development of both new-generation penetrator designs, and space missions involving their use.