by Alex Nakahara
For many, balloons are an anachronism. In days where jets carry us across the country in hours and rockets carry people into orbit, balloons appear useless. I can sit at my desk and look at the Philadelphia Zoo Balloon, a mere amusement park ride for visitors, going slowly up and down all day, never going anywhere. At least their lighter-than-air fellows, the blimps, get to float above sporting events every weekend. Balloons are stuck as tourist attractions or the playthings of devoted hobbyists. However, balloons are enjoying a minor renaissance in an unexpected area: space.
Several groups of students and others have realized that, while it takes millions upon millions of dollars to build a rocket capable of reaching space, relatively cheap weather balloons filled with helium can fly as high as 20 miles above the Earth, allowing a look at space for anyone willing to make the effort. These MIT students built such a system for only $148! I myself just submitted my senior design project proposal to develop a lab for an engineering course where students would build their own space balloon and try to predict its flight path, the deformation of the balloon, and several other aspects, and then compare their predictions to the actual flight.
Such space balloons are not just the province of low-budget students. The BLAST project (Balloon-borne Large-Aperture Sub-millimeter Telescope, whose head, Mark Devlin, is a professor here at Penn), attached a large telescope to an even larger balloon in order to get better pictures of space. The lower atmosphere of the Earth blocks and distorts incoming light and energy waves due to pollution, weather, and just the amount of air. By floating the telescope into the upper atmosphere, the researchers in effect created their own version of the Hubble telescope, at a fraction of the cost.
Obviously balloons will never be as widely used as aircraft, rockets, or even blimps. However, they show the potential for old technologies to be turned towards new uses. They are perfectly suited for this small niche, showing that the best options aren’t always the newest or most expensive.