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Space junk more dangerous as C02 accumulates in the atmosphere

space junk will accumulate at a faster rate and we will see more collisions between space objects as a result

CO2 build-up risks increasing space junk Herald Sun, AAP November 12, 2012   A BUILD-UP of carbon dioxide in the upper levels of Earth’s atmosphere risks causing a faster accumulation of man-made space junk and resulting in more collisions, scientists say.

While it causes warming on Earth, CO2 conversely cools down the atmosphere and contracts its outermost layer, the thermosphere, where many satellites, including the International Space Station (ISS), operate, said a study published in the journal Nature Geoscience.

A contracted thermosphere, in turn, reduces atmospheric “drag” on satellites – a similar force to that experienced when holding one’s hand out the window of a moving car.

This “drag” is what causes satellite orbits to change, drawing them closer to Earth, which means that orbiters like the ISS have to boost themselves back on course with on-board engines.

“The observed CO2 increase is expected to gradually result in a
cooler, more contracted upper atmosphere and a consequent reduction in
the atmospheric drag experienced by satellites,” said a statement from
the Naval Research Laboratory, which took part in the study.

Commenting on the paper, space expert Hugh Lewis said a cooler
troposphere will extend the lifetime of space junk – staying farther
out for longer instead of burning up in the lower layers of the
atmosphere, closer to Earth. “Consequently, space junk will accumulate at a faster rate and we will see more collisions between space objects as a result,” he told AFP.

“We will also see many more ‘near-misses’ and these have an important effect on spacecraft operators.”….
http://www.heraldsun.com.au/news/breaking-news/co2-build-up-risks-increasing-space-junk/story-e6frf7k6-1226514823555

November 12, 2012 - Posted by Christina Macpherson | 2 WORLD, climate change