In 2007, a team of British rocket enthusiasts spent 4,000 pounds (roughly 6,000 U.S. dollars) on a homemade rocket. Designed by rocketeer Richard Brown, the rocket stood 12.5 feet (3.8 meters) tall and was dubbed "Corpulent Stump." At the time, it was the largest amateur rocket ever built, but still only ascended to an altitude of roughly 1.1 miles (1.8 kilometers). That's far shy of both the Kármán line and NASA's 50-mile (81-kilometer) border.
Three years earlier, the U.S.-based Civilian Space eXploration Team (CSXT) successfully launched the first amateur rocket into space. That rocket allegedly reached an altitude of roughly 70 miles (113 kilometers) [source: AP]. While CSXT's expenses aren't publicly known, estimations run in the tens of thousands of dollars [source: Graham-Rowe]. Of course, such high costs are the reason the X Prize Foundation and likeminded organizations exist: to provide lucrative cash prizes to those who push the boundaries of independent space research.
So let's forget about building a space rocket in your shed, at least for the moment. What about balloons?
The idea itself is nothing new. NASA successfully launched the first space balloon, Echo 1A, on Aug. 12, 1960, to an altitude of 1,000 miles (1,609 kilometers). Again, if space begins at either the 62-mile (100-kilometer) or the 50-mile (81-kilometer) point, the historic flight more than qualified the balloon as a spacecraft. The 31,416 square-foot (2,918 square-meter) balloon consisted of a reflective aluminum coating over an inflated Mylar plastic sphere [source: Choi]. You can think of it as an absurdly oversized Christmas tree ornament -- one capable of reaching staggering altitudes.
Several amateur "space balloons" have made the headlines in recent years, and with good reason. For instance on Sept. 30, 2010, a father and son team out of Brooklyn, N.Y., attached a camera to a balloon and captured stunning footage of the edge of space. It's an inspiring story, certainly, but it also only reached an altitude of 19 miles (31 kilometers), short of accepted space/atmosphere borders. As such, these ambitious efforts have only reached "near-space."
So for now, space flight would seem to remain the exclusive domain of nations and private companies.
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