The paper considers the description of phenomena in the own outboard atmosphere of spacecraft observed in the space experiment on the creation of the solar eclipse during the joint Soyuz–Apollo mission. It is shown that the transfer of solar radiation via gas-dust environment of own outboard atmosphere detected by the luminosity emanating from the shadow region outboard of the Apollo spacecraft when creating an artificial solar eclipse is an experimental result that confirms the theoretical conclusions on the similar exposure to radiation of the spacecraft with the nuclear power unit placed in the shadow of the radiation safety unit.