<text><span class="style10">pace Exploration (1 of 5)</span><span class="style7">The development of space technology has been remarkably rapid. Less than 10 years after Yuri Gagarin became the first person in space, Neil Armstrong set foot upon the Moon. During the 21st century, space travel is likely to become routine. Permanent space stations will operate in Earth orbit, bases will be built on the Moon and man will begin to explore the planet Mars.The theory of rocketry was developed at the beginning of the 20th century by the Russian physicist Konstantin Tsiolkovsky (1857-1935). He produced designs for multistage liquid-fueled rockets decades before such vehicles were actually built. Tsiolkovsky also wrote about space suits, satellites and colonizing the Solar system. The inscription on his tombstone reads `Mankind will not remain tied to Earth forever.'</span><span class="style10">The pioneers of rocketry</span><span class="style7">The first successful liquid-propellant rocket was launched by the American physicist Robert Goddard (1882-1945) in 1926. By the mid-1930s, Goddard had perfected rockets that could travel to an altitude of several kilometers.Born in Germany, Wernher von Braun (1912-77) helped to develop the V-2 rocket during World War II. He surrendered to the Americans in 1945 and led the team that launched </span><span class="style26">Explorer 1</span><span class="style7"> in 1958, the first American artificial satellite. He then turned his attention to the Apollo program, which landed a man on the Moon in 1969.</span><span class="style10">The first artificial satellites</span><span class="style7">The first object successfully launched into space was the Soviet </span><span class="style26">Sputnik 1</span><span class="style7">, which lifted off on 4 October 1957. The satellite measured temperatures and electron densities, before burning up as it re-entered the atmosphere on 4 January 1958.The dog Laika became the first living creature in space following her launch aboard </span><span class="style26">Sputnik 2</span><span class="style7"> on 3 November 1957. Laika spent 10 days in orbit, but died when her oxygen supply was exhausted.</span></text>
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<text><span class="style10">he Lunar Roving Vehicle</span><span class="style7"> or `moon buggy' in action among the foot hills of the Lunar Apennines. The LRV was taken to the Moon by Apollo 15 in 1971</span></text>
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<text>ΓÇó THE INNER PLANETSΓÇó THE OUTER PLANETSΓÇó NUCLEAR ARMAMENT AND DISARMAMENTΓÇó ENGINESΓÇó SEEING THE INVISIBLEΓÇó AIRCRAFT</text>
