use of reconnaissance satellites raised a sensitive question under
international law: was space free to all, like the open seas, or
was it like airspace, part of a nation's sovereign territory?
Eisenhower and his advisors sought to ensure international acceptance
of the freedom of space. They planned to use the 1957 International
Geophysical Year, a world-wide cooperative scientific study of the
Earth, to set this precedent.
decided that a science satellite--already part of the IGY plan and
less controversial than a spy satellite--would make the United States'
first foray into space. Launches of the U.S.S.R.'s Sputnik in late
1957 and the U.S. Explorer 1, a science satellite, in January 1958
were the first steps toward freedom of space.
National Academy of Sciences