The Space Race, one of many fronts of the Cold War, began in earnest on July 29, 1955, when President Eisenhower publicly announced Project Vanguard, the first genuine effort to launch a man-made vehicle into orbit as an instrumented scientific experiment for the International Geophysical Year. Bypassing Werner Von Braun’s more proven Army ballistic missile, the launch vehicle chosen was the more scientific Naval Research Lab’s new multistage rocket, in hopes of avoiding Soviet confrontations about overflights.
A week later, on Aug. 8, the Soviet Union secretly decided to create and launch a Soviet satellite, Project D, in advance of Project Vanguard, to be placed in orbit by their new R-7 intercontinental ballistic missile (ICBM), which was designed to deliver and detonate 3 megaton thermonuclear warheads over US population centers.
Project D would be jam-packed with every conceivable scientific instrument.
Over the next 2 years the R-7 missile experienced a number of test failures and delays. The Project D satellite also fell behind schedule when it was discovered that the satellite was simply not large enough to host all of the planned instruments. Fearing that they would not be able to reach orbit before Project Vanguard, the Soviets decided to instead launch a very small, simple satellite, Sputnik I, totally devoid of any scientific instruments and only containing a radio transmitter, which they put into low Earth orbit on Oct. 4, 1957, just 63 days before the first Vanguard launch attempt.
The social impact of Sputnik was enormous. Across the world, people could look up at the nighttime sky and see a new, bright, first-magnitude star rapidly moving across the sky. This was not Sputnik. This was the enormous second stage of the R-7 ICBM, covered with highly reflective panels, trailing behind a barely visible 6th-magnitude speck, Sputnik. In stark contrast, Americans watched the televised failure of the Vanguard rocket as it collapsed onto the launch pad and exploded.
Several months later, after the U.S. also successfully launched Explorer I, Vanguard I was placed into orbit, where it transmitted signals for seven years, and still remains, today, the oldest man-made vehicle in space.
And without it, Sputnik I, Vostok I, Apollo 8, Apollo 11, the space shuttle, Voyager, Hubble, the International Space Station, Spirit and Opportunity, Kepler, etc. quite possibly would never have happened.