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up, Up and Away - NASA Article<br /><font color="orange">Scientists hope to learn more about climate changes here on Earth by studying Venus. A prototype balloon could eventually study the planet's surface and examine its atmosphere and the bizarre winds and chemistry within it. A team of JPL, ILC Dover and NASA Wallops Flight Facility engineers designed, fabricated and tested the balloon.<br /><br />Slightly smaller than Earth, Venus is often regarded as Earth's sister planet. Both have similar densities, chemical compositions and gravities. However, its atmosphere is nearly 100 times thicker than Earth's, which causes blazing temperatures at the surface. By flying in the cool skies above Venus, the balloons would avoid that environment.<br /><br />"The surface is hot enough to melt lead, which is why we can't study it for long from a lander," said Kevin Baines, JPL principal investigator for a proposed mission to Venus. "Without extreme and costly refrigeration methods, a lander would cook at those temperatures in just a few hours, but a balloon can stay in a benign environment, studying the planet for days, weeks or even months."<br /><br />The spherical balloon, 18 feet in diameter, is about the size of an inflatable children's jumper. Its aluminum coating reflects sunlight to protect the balloon from becoming too hot as it flies in Venus' upper atmosphere. Its outer transparent layer of the balloon is made of polytetrafluorethylene, also known as Teflon, the non-stick material found in cookware and on clothing. The material is highly resistant to the sulfuric acid found in clouds surrounding Venus. "The sun shines through the Teflon and reflects off the aluminum, and that keeps the balloon from overheating," said Jeff Hall, JPL's lead balloon engineer.<br /><br />The balloon's second layer has a mylar film similar to those shiny helium balloons found in a grocery store. The myl</font> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>