Obitaemyi ostrov [Prisoners of Power]

Maxim Kammerer is a young amateur space explorer from Earth, regarded as a failure by his friends and relatives because this occupation is not considered to be a serious pursuit. The novel starts when he accidentally discovers an unexplored planet Saraksh inhabited by a humanoid race. The atmospheric conditions on Saraksh are such that the inhabitants believe that they live inside a sphere. The level of technological development on the planet is similar to mid-20th century Earth. The planet recently came through big nuclear and conventional war and the predicament of the population is dire. When Maxim lands, the natives mistake his small spaceship for a weapon and destroy it.