Abstract: A system for retrieving at a given station, either on the ground or in the ir, data from a site on the earth's surface from which ground-based communication would be impracticable, either because of configuration of terrain or of the existence of intervening natural or man-made obstacles, wherein an assembly comprising a rocket module and a surface module connected together by an umbilical connector is emplaced directly or by air drop at the site and wherein the data is acquired at the site by sensors located within the surface module and recorded by a recorder located within the rocket module.