Аннотация:THE CORRESPONDANCE BETWEEN K.E. TSIOLKOVSKY AND A.L. CHIZHEVSKY AS A SOURCE OF STUDYING LIFEAND CREATIVE WORK OF THE SCIENTISTSE.V. ArhiptsevaThe Konstantin E. Tsiolkovsky State Museum of the History of Cosmonautics, Kaluga cityThe article is devoted to possibilities of private correspondence sources in the investigation of a creative person phenomenon. Materials containing the long epistolary dialogue between the two outstanding people from the collection of the Konstantin E. Tsiolkovsky State Museum of the History of Cosmonautics are considered. K.E. Tsiolkovsky who achieved the worldwide recognition as the founding father of theoretical cosmonautics owing to his fundamental work “The Exploration of Outer Space by Means of Rocket Devices” published in 1903 is one of them. Another person is A.L. Chizhevsky a famous physicist, the founding father of heliobiology, who published his classical work “The physical factors of the historical process” in 1924 where he analyzed “the life of the Earth and the Sun”. Having studied the relations between the sunspots and the global historical process the scientist established the connection between historical events and protuberances, found out that the world history of humanity depended on the periods of maximum solar activity, that is why he got thenickname “Sun-worshipper”. K.E. Tsiolkovsky and A.L. Chizhevsky wrote each other about scientific work and scientific contacts. Considerable attention was paid to the questions connected with publication. They discussed contents of articles, titles of periodicals, deadlines for publications, illustrations, publications' payment and postal orders, censorship fee. e correspondence is both creative and biographical. e letters include biographical informationabout the correspondents, touches upon their everyday life. e authors complained of financial problems, wrote about their health, and shared their joy and worries. K.E. Tsiolkovsky’sletters were written on small postal cards, or on pieces of paper put inside handmade envelopes. He had small handwriting, a lot of contractions were in his texts. Tsiolkovsky had tosave paper which was difficult to get, and sometimes he did not even have enough money tobuy it. Some letters of Professor A.L. Chizhevsky, the Director of the Central Scientific Research Laboratory of Ionization, were written on a laboratory letterhead. These letters arethe witnesses of the epoch of the first third of the 20th century. At the same time they presentoutdate classical genre of letter-writing.Keywords: the correspondence, the epistolary heritage, the private unique sources,historiographic analysis, biographical researches, the scientific contacts, K.E. Tsiolkovsky,A.L. Chizhevsky.АННОТАЦИЯСтатья посвящена анализу эпистолярного наследия как источника изучения феномена творческой личности учёного. Рассматриваются материалы обширного письменного диалога двух выдающихся деятелей: основоположника теоретической космонавтики К.Э. Циолковского и основоположника гелиобиологииА.Л. Чижевского. Переписка хранится в Государственном музее истории космонавтики имени К.Э. Циолковского и касается темы научного творчества и научных контактов, освещает биографические данные корреспондентов, затрагивает бытовые темы. Представленные документы – свидетели эпохи первой третиХХ века – являют собой ушедший в прошлое классический жанр эпистолярия.Ключевые слова: эпистолярное наследие, источниковедческий анализ, биографические исследования, научные контакты, К.Э. Циолковский, А.Л. Чижевский.