Uh-oh, this looks worrying....
http://www.nature.com/news/2010/101022/ ... 0.558.htmlHere is the opening of this quite long article:
Quote:
Climate change caused by black carbon, also known as soot, emitted during a decade of commercial space flight would be comparable to that from current global aviation, researchers estimate.
The findings, reported in a paper in press in Geophysical Research Letters1, suggest that emissions from 1,000 private rocket launches a year would persist high in the stratosphere, potentially altering global atmospheric circulation and distributions of ozone. The simulations show that the changes to Earth's climate could increase polar surface temperatures by 1 °C, and reduce polar sea ice by 5–15%.
Quote:
Private space flight is a rapidly maturing industry. Spaceport America, a launch site in Las Cruces, New Mexico, opened its first runway on 22 October. During the next three years, companies such as Virgin Galactic, headquartered at Spaceport America, expect to make up to two launches per day for space tourists. Meanwhile, the NASA Authorization Act passed by US Congress in September provides US$1.6 billion in private space-flight investments to develop vehicles to take astronauts and cargo into orbit.
“There are fundamental limits to how much material human beings can put into orbit without having a significant impact.”
Commercial rockets burn a mixture of kerosene and liquid oxygen. But several private space-flight companies, such as Virgin Galactic, may soon use a more economical 'hybrid' rocket engine that ignites synthetic hydrocarbon with nitrous oxide, says Ross. These hybrid engines emit more black carbon than a kerosene and oxygen engine, he adds.
"Rain and weather wash out these particles from the atmosphere near Earth's surface, but in the stratosphere there isn't any rain and they can remain for 3 to 10 years," says Michael Mills, an atmospheric chemist at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, and another author of the paper.