Environmental concerns grow as space tourism lifts off

The nascent space tourism industry has found itself facing tough questions about its environmental impact.

After years of waiting, Richard Branson's journey to space this month on a Virgin Galactic vessel was supposed to be a triumphant homecoming. Instead, the jaunt attracted significant criticism -- about its carbon footprint. With Jeff Bezos set to launch on a Blue Origin rocket on July 20, and Elon Musk's SpaceX planning an all-civilian orbital mission in September, the nascent space tourism industry finds itself facing tough questions about its environmental impact.