The “Icare” experiment, involving a balloon at a height of about 30 km was described. The gondola was made of polystyrene, the reasoning being that micrometeorites, by virtue of their velocity, would embed themselves in this to a sufficient degree that they would not be lost during the payload’s recovery and subsequent handling.

Electron microscope examination revealed dust particles collected during the flights, and micro-analysis suggests that these are truly of extraterrestrial origin.