The compact car-sized Mars Science Laboratory is due to land on the red planet on Aug. 6, 2012. It is equipped with a suite of instruments to study rocks and soils, and take other measurements. NASA/JPL-Caltech hide caption

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Astrophysicist Saul Perlmutter analyzed the brightness coming from supernovae, like the one pictured above, to measure how fast the universe is expanding. NASA hide caption

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American astronomer Edwin Hubble looks through the eyepiece of the 100-inch telescope at the Mount Wilson Observatory in Los Angeles, 1937. In 1929, Hubble proposed that the more distant a galaxy is, the faster it appears to be receding from us, a concept that has become known as Hubble's law. Margaret Bourke-White/Time & Life Pictures/Getty Images hide caption

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In 1962, President John Kennedy (center) and Vice President Lyndon Johnson visited Dr. Wernher von Braun (left), who designed the Saturn rocket in Huntsville, Ala. AP hide caption

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NASA's next Mars rover, Curiosity, seen in this artist's rendering, will use 8 pounds of plutonium-238 as its power supply. That's a significant portion of the remaining space fuel. NASA and the Department of Energy have offered to split the costs of producing the fuel, but Congress has so far opposed that arrangement. NASA hide caption

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Nicolaus Copernicus made the astounding claim that Earth revolves around the sun, not the other way around. He's seen here circa 1515. Hulton Archive/Getty Images hide caption

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A massive galaxy cluster about 3 billion light years from Earth. Chandra X-ray Observatory/Smithsonian Institution/Flickr hide caption

itoggle caption Chandra X-ray Observatory/Smithsonian Institution/Flickr

Phil Pressel designed cameras for the government's top-secret Hexagon project. He's only recently been able to speak about his life's work.

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