Page 24 - Curriculum Visions Dynamic Book

This space mission not only discovered many things about how living things survive in space, but also about solar radiation and other radiation in space. For instance, it was learned that there was a radiation belt around the Earth.
The American challenge
Sputniks 1 and 2 represented one of human beings’ greatest achievements: sending something out to beyond the Earth’s atmosphere. Their effect was to electrify the world and to galvanize many countries into ever greater action—the main competitor for the Soviet Union being the United States.
Although the Soviet Union was the first to put something in space, the United States had also been developing space vehicles for decades. Less than 4 months after Sputnik the U.S. tried to launch Explorer, a mission speeded up by political pressure. The satellite to be carried was tiny: just 1.4 kg, no bigger than a grapefruit. But the small rocket pressed into use for this attempt could not even lift itself from the launch pad by more than a few metres.
It was clearly necessary to use a bigger launch vehicle, and that was provided by the military rocket named Jupiter.
Explorer and Vanguard
It was not until January 31, 1958, that the first successful launch of an American satellite occurred. The satellite weighed just over a kilogram and looked like a cylinder. It was called Explorer 1.
The Explorer series was the first successful step
in the American challenge. Each satellite in the
series was designed to find out more about the outer atmosphere where manned spacecraft would be flying. Explorer 1 carried geiger tubes that detected radiation. The experiments were conducted by Dr. James Van Allen. The radiation belt around the Earth detected by these tubes would be called the Van Allen belt.
 The explosion of an early Navy Vanguard rocket. On December 6, 1957, carrying a satellite payload, it failed to develop enough ThrusT and toppled over on the launch pad. So soon after the successful launch into orbit of Sputnik, Vanguard was nicknamed “kaputnik.” It simply showed how difficult space launches are.
array A regular group or arrangement.
atmosphere The envelope of gases that surrounds the Earth and other bodies in the universe.
geiger tube A device to detect radioactive materials.
radiation The transfer of energy in the form of waves (such as light and heat) or particles (such as from radioactive decay of a material).
solar cell A photoelectric device that converts the energy from the Sun (solar radiation) into electrical energy.
solar radiation The light and heat energy sent into space from the Sun.
thrust A very strong and continued pressure.
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