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BARREL researchers get ready to release the top part of the balloon, called the bubble, as it fills with enough helium to support itself. Only the top part of the balloon is inflated before launch since the helium expands as the balloon ascends. Credit: NASA/Goddard/BARREL/Nicky Knox Read more: <a href="http://www.nasa.gov/content/goddard/nasas-barrel-returns-successful-from-antarctica" rel="nofollow">www.nasa.gov/content/goddard/nasas-barrel-returns-success...</a> -- Three months, 20 balloons, and one very successful campaign. The team for NASA's BARREL – short for Balloon Array for Rad…
