Optical effects of running spacecraft engines in the lower thermosphere

This paper provides a brief overview on optical effects during operation of spacecraft (SC) onboard engines in the lower thermosphere according to observational data from the ISTP SB RAS Geophyisical Observatory. We present the results of detected disturb-ances in the night airglow during operation of SC verni-er engines in the F2-region of the ionosphere in the "Radar-Progress" space experiment. With weights of combustion products of & LE;10 kg injected by SC vernier engines, the atmospheric emission of [OI] 630.0 nm atomic oxygen is enhanced. We also show optical ef-fects from the launches and passages of heavy launch vehicles "Energiya" from the Skif-DM spacecraft on May 15, 1987 and "Proton-M" from the Yamal-601 spacecraft on May 30, 2019 from Baikonur in the zone far from the launch site. We explore the possibility of enhanced [OI] 557.7 nm atmospheric emission due to chemical modification of the ionosphere in the E-region during the flight of the Energiya space system.