The Chemical and Mineral Composition of Particles Precipitated from a Plasma–Dust Layer on the Porthole of the Descend Space Vehicles during The Passage of the Earth’s Atmosphere

Electron microscopic studies of the surface of the spacecraft descent vehicle (DV) have revealed faceted particles of various shape and size, which are formed when the DV travels through the Earth’s atmosphere at an ultrasonic velocity. The particles are no more than 5 µm in size. An X-ray diffraction analysis of the phase composition of the precipitate on the DVs porthole after their landing showed that the test samples contain the following minerals: сryptohalite—(NH 4 ) 2 [SiF 6 ]), sal ammoniac—NH 4 Cl, mullite—Al 2 SiO 5, and other minerals that rarely occur in nature. The paper presents results of electron microscopic and X-ray studies of samples taken from 4 descent vehicles.