Aleksandr Yakovlevich Orlov, astronomer contributed “Astronomic Utopias” in which he discussed the potential living on
Mars and the
Moon and provided a sketch of what he thought an engine for interplanetary travel might look like.
Aron Zalkind (1888–1936), a psychologist. He was accused of "Menshevist-idealistic eclecticism" in 1931. He was later obliged to recant his
Freudian views.