Experimental demonstration of the feasibility of laser communication with reentry spacecraft at 1.55  μm.

It has been demonstrated experimentally for the first time, to the best of our knowledge, that reliable laser communication at 1.55 μm can be established with reentry spacecraft across the entire atmospheric descent trajectory as a way to avoid radio blackout. A plasma sheath with parameters similar to those around the spacecraft is reproduced at the Lomonosov Moscow State University Mechanics Institute Shock Tube Facility.

Si3N4-TiN nanocomposite by nitration of TiSi2 and consolidation by hot pressing and spark plasma sintering.

Homogeneous nanostructured Si3N4-TiN composite powder was obtained by nitration of a TiSi2 powder precursor in a nitrogen flow. Mechanoactivation of titanium disilicide increases the nitration rate and reduces the temperature of formation of the Si3N4 and TiN. The properties of hot pressing (HP) and spark plasma sintering (SPS) of the nanostructured Si3N4-TiN composite with Y2O3 and Al2O3 additives have been studied.