スプートニク・ショック
One of the first known references of the study of interplanetary communication comes in 1954 with the development of the Sputnik 1 satellite by the Soviet Union when Mikhail Tikhonravov emphasized that an artificial satellite is an inevitable stage in the development of rocket equipment, after which interplanetary communication would become possible. With the successful launch of Sputnik 1 in 1957, the United States entered into the [[Sputnik crisis]] and, more generally, the [[Space Race]] with the Soviet Union.