KONSTANTIN TSIOLKOVSKY (1857-1935) Pioneering Russian scientist and rocket designer who laid out the basic principles of modern space flight. Rare A.Ms.S. signed on recto and twice more on verso, 2pp. 4to., [n.p., n.d.], in Russian. Untranslated, but appears to be a simple blueprint, possibly depicting a rocket engine, with much annotation and later additions by Tsiolkovsky in his hand. One marginal chip costs two or three words of text, else very good. With letter of authenticity issued by the International Charitable Foundation for Support of Russian Cosmonauts. $600-800