ИСТИНА

Small satellites are very appropriate for the study of different physical phenomena, which can be dangerous for spacecraft technique and biological objects. The transient electromagnetic events, such as Terrestrial Gamma Ray Flashes (TGF), Transient Luminous Events (TLE) and cosmic Gamma Ray Bursts (GRB) as well as magnetosphere electron flux dynamics are very important factors of natural hazards in the near-Earth space. These phenomena were observed during the space experiment with RELEC (Relativistic Electrons) instruments on board Vernov small satellite from July to December, 2014. The solar-synchronous orbit with small eccentricity (640x830 km), inclination about 98o and period ~98 min provides favourable conditions for the magnetosphere electron precipitation (MEP) study as TGF and TLE observations in different areas of the Atmosphere including Equatorial and Polar Regions. As the results of observations on Vernov satellite dozens of TGF candidates and thousands of UV and red flashes most likely associated with TLEs and lightning were detected. The MEPs were also observed regularly in different areas of near Earth space. Some of TGF candidates and UV flashes were observed at high latitudes in the regions far away from thunderstorms, but near the MEP areas that could indicate on possible connection between TGF and TLE, i.e. high altitude discharges and MEP. Such observations were continued on Lomonosov satellite which was launched on April, 28 2016 to the solar-synchronous orbit with 490 km altitude and inclination ~98o. The short-time variations of sub-relativistic and relativistic (0.1 – 3.0 MeV) electron flux variations were detected during Vernov and Lomonosov missions in the different parts of near-Earth space, including Aurora regions. The typical times of such events are in the range from several milliseconds up to dozen of seconds and even minutes. The spatial effects caused by satellite crossing of electron beams or other areas with increased electron density and pure temporal, i.e. burst-like phenomena may be among them. The experience of Vernov and Lomonosov mission for future project of multi small satellites for Monitoring of Natural and Artificial Space Hazards is also discussed.