Analysis of information sources in references of the Wikipedia article "Mstislav Keldysh" in English language version.
"In 1954 . . . because they knew a lot of Soviet journalists, they flooded the Soviet media with speculative articles on space flight .. cited a lot in the Washington Post and New York Times. July 1955, the Eisenhower administration announces they're going to launch a satellite in a couple of years, it's going to be a scientific satellite