On a list of the sources of climate change, a handful of activities matter most: for American consumers, the biggest causes are energy use in the home, driving, and plane travel. Now, something new might join the group of worst offenders. Yesterday, Virgin Galactic tested its new commercial rocket for the first time. As space tourism takes off, it could soon affect global climate as much as the world’s entire fleet of subsonic airplanes.
Space tourism officially began in 2001, when businessman Dennis Tito paid a reported $20 million to take a ride to the International Space Station on a Russian Soyuz spacecraft. By 2004, SpaceShipOne, the world’s first privately funded and operated space vehicle, had been successfully tested. Space Adventures, Inc., has been taking reservations for space flights since 1998. But it’s only now that space tourism—also known as "personal spaceflight," or "citizen space exploration"—is taking off on a larger scale.
In New Mexico, Virgin’s new launch base, Spaceport America, is getting ready for its first commercial flights next year. Virgin Galactic has hundreds of reservations for the flights, which will take customers more than 60 miles above the surface of the Earth, where the planet’s atmosphere ends and space begins. When customers reach space, they’ll have six or seven minutes to float weightlessly in the cabin and view Earth below; then the spaceplane will begin to return to Earth.
Virgin's not alone. XCOR, with a spacecraft that seats only one customer, also has hundreds of reservations for its first flights. A handful of other companies also have flights planned. In total, the industry estimates that 13,000 people will have been space tourists by 2021. That pales in comparison to the number of passengers on ordinary airplanes—in the United States alone, there will be over 700 million air passengers in 2012, and by 2024, there will be one billion per year. But the impacts from one rocket flight are so much worse that planes and spaceplanes may be roughly equal contributors to climate change in a decade.
Though spaceplanes create carbon dioxide, the biggest impact will come from black carbon, or, as it’s more commonly known, soot. While commercial rockets run on kerosene and liquid oxygen, companies like Virgin Galactic plan to use "hybrid" rocket engines. Not to be confused with hybrid cars, these engines have nothing to do with electricity—they run on synthetic hydrocarbon and nitrous oxide. The engine makes the spaceplanes cheaper to run than typical rockets, but the new spacecraft also emit substantially more black carbon.
A 2010 study, funded in part by NASA, showed exactly how serious that black carbon could be, with computer models showing the potential for as much as a degree of warming over the poles. The study's authors say it's not exact, since the only way to get hard data will be to fly the rockets—but it indicates the potential of the problem. Virgin has acted as an environmental leader in many other ways, like helping design extra-lightweight planes and spacecraft to save energy, and even building a LEED-certified spaceport. They plan to use their rockets for environmental research. But the challenge of black carbon still hasn't been solved, and flights are moving ahead.
Is six minutes in space, for a handful of very wealthy individuals, worth the potential risk to our atmosphere?
Images courtesy of Virgin Galactic.