Ключевые слова: aged, astronauts, collection, communications, cosmos, departure, envelope, exploration, flight, gubarev, historic, history, hobby, illustration, isolated, launch, letter, mailing, mark, message, missile, old, orbit, paper, perforation, philately, pilot, post office, postage, postal, postcards, postmark, progress, research, retro, rocket, russia, salyut 4, science, soviet union, soyuz 17, space suit, spacecraft, stamp, station, symbol, technology, transportation, ussr, weightlessness,