Sometimes, scientific research can look like good-old fun. When the word "NASA" gets sprung into a conversation, most of us think of rockets, the moon, Mars and maybe the International Space Station. I certainly don't think of balloons.

Any yet the balloon is one of the most often-forgotten but utterly crucial tools in NASA's kit of atmospheric equipment. Granted, these high-altitude balloons are much more sophisticated than the ones you get at birthday parties, and probably a LOT more expensive, but they are basically built the same.

And just a few weeks ago, NASA tested a balloon which was able to stay in the air for over 42 days — far longer than any of the balloons I've ever kept after a party.

Did you know? The previous record for a high-atmosphere balloon was some 42 days, set in during an experiment to study cosmic rays.

And a lot of research has gone into making these ultra-light weight, helium filled balloons. They are particularly useful because they are much cheaper and easier to make than a rocket, and are potentially much more stable. Also, by getting machines so high in the atmosphere, astronomers can cut out a lot of interference from the earth — getting good photos of stars for study.

Did you know? Telescopes on earth have to deal with a lot of 'atmospheric pollution' — lights from nearby cities, clouds, dust and gasses like smog. These interfere with images of heavenly bodies, making detailed measurements tough.

However, if I was to release a helium balloon from the local store into the atmosphere, it will eventually pop. As the balloon rises, the atmosphere thins — there's less air pressure the higher you go. What that does is expand the balloon, until eventually it will suffer a tear and lose all the helium, dropping to the ground. Also as the balloon climbs, the temperature changes. These temperature fluctuations can really affect the material in the balloon, as well as the pressure of the gases inside, and therefore how high the balloon will eventually reach.

Did you know? High-altitude balloons often reach heights of 18-35 Km above the Earth.

To combat these problems, NASA has developed balloons which are made of a metallic coating, which keeps the helium inside. To prevent the expansion of the balloon, they are protected with a set of ribs, which coat the balloon and prevent it popping when the gas expands.

The latest balloon, by NASA reports, has been a rousing success — having only changed altitude by some 700 metres, and gently riding the atmospheric 'Polar Vortex Winds' circling Antarctica, hopefully coming down just short of a 100 day record-setting voyage.

Polar Vortex Winds: are a set of air movements which go around the poles of the earth. They form as a result of the long polar nights (which go for months during the winter), which leads to a circular column of air which circles the pole. The wind speed in these columns has been measured as high as 100 meters a second (~360 km/hr)!

While this balloon is carrying equipment it wasn't doing any experimentation. However it has set the scene for future experimental balloons to follow, as early as this summer.

Learn more

http://www.nature.com/news/2009/090208/full/news.2009.85.html

http://www.nasaimages.org/luna/servlet/detail/NVA2~14~14~26619~124207:HIGH-ALTITUDE-BALLOON-ARCTIC-OZONE

http://imagine.gsfc.nasa.gov/docs/features/topics/instrument_design/gamma-ray_balloons.html

Martin Lee Ph.D. Writer

Martin is a physical biochemist, who is studying the way embryos control their DNA in the first few days after fertilization. Originally from New Zealand, he’s been living in Canada for the last few years “enjoying” the winter months.

CurioCity writer

Article written by a CurioCity expert.


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