In the rocket business, most of what goes up eventually comes back down. And either direction can be a problem for our planet’s atmosphere.

Studies have shown that rocket exhaust can increase temperatures in the upper atmosphere. That could influence hurricane formation, monsoons, and surface temperatures. It also creates chemical reactions that deplete the protective ozone layer.

And a recent study suggests that spacecraft reentering the atmosphere could cause problems, too.

Much of a spacecraft is made of aluminum. As it burns up in the atmosphere, the aluminum either vaporizes or disintegrates into small particles. The larger particles drop to the surface within hours. But the smaller ones can stay in the upper atmosphere for thousands of years. There, both the particles and the vapor can create chemical reactions that damage the ozone layer or form greenhouse gases, which contribute to global warming.

The number of launches is going way up. There were more than 180 launches last year, carrying about 2,000 satellites — both records. And the year before, more than 300 tons of satellites fell back to Earth. And all of those numbers are expected to keep going up in the years ahead. The new study says if those projections are right, then reentering satellites could add more than 550 tons of aluminum to the upper atmosphere every year. And that could be bad news for our changing environment.
 

Script by Damond Benningfield

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