Who can make the greenest rocket?
As private space tourism nears launch, some companies are climbing to new heights for less-polluting rockets.
Fri, May 22, 2009 at 09:33 AM
Photo: Mike Massee/XCOR
Space may soon be a tourist destination. A handful of well-funded private companies are jockeying to be the first to blast paying customers to the edge of space, where they’ll experience weightlessness and stare out into the void. These suborbital flights are expected to begin next year. And there’s a surprising twist to this new space race: The companies aren’t just competing to launch first; several are also vying for bragging rights to the greenest rocket. Firing off rockets to give rich tourists a stellar view may sound inherently un-eco, especially given the conventional airline industry’s contributions to global warming. There’s no arguing that the practice will emit greenhouse gases, but space industry leaders Xcor Aerospace and Virgin Galactic tout their programs as “environmentally benign.”
“The motivation wasn’t necessarily that we wanted to join Greenpeace,” says Xcor spokesman Doug Graham. His company sought to build a fuel-efficient vehicle that would keep costs down. Xcor also needed a nontoxic fuel that would be easy to handle. So it built a small, two-seated vehicle powered by kerosene and liquid oxygen, which burns cleanly at about 6,000°F and emits no smoke or particulate matter. Xcor has also helped design a methane-fueled engine; it’s an even greener technology because, unlike the petroleum-based kerosene, methane is a renewable energy source. “Theoretically, we could get the methane from anywhere, even from cow manure,” Graham says.
Virgin Galactic plans to send passengers 62 miles up using an innovative two-vehicle design that may give the company a green edge. The larger mothership takes off from a runway and carries an attached rocket to 50,000 feet, at which point the rocket’s engine ignites, shooting off the smaller craft for the final climb. While Virgin’s rocket fuel is more toxic than Xcor’s, Virgin says its design is environmentally superior because of its “air launch” system.
“To launch something from the ground through the very thick atmosphere and get out to suborbital space, you have to do a huge blast—you have to detonate a bomb, basically,” says Virgin Galactic CEO Stephen Attenborough. The Virgin system uses less fuel because the rocket engine has to fire for only 90 seconds to reach thinner atmosphere. Attenborough says Virgin calculated that each of the rocket’s six passengers will have a carbon footprint totaling 0.8 metric tons of carbon dioxide; in comparison, a passenger on a 747 jet from New York to London is responsible for two metric tons.
Global warming activists haven’t taken much notice of space tourism yet. That’s fine for now, according to Deron Lovaas, who studies transportation and energy for the environmental nonprofit Natural Resources Defense Council. The space companies are already selling tickets for future flights costing between $100,000 and $250,000. At that price, their flights aren’t likely to become a major contributor to global warming, Lovaas says. “These customers will be the same people who don’t hesitate to buy a top-of-line Jaguar. To use that analogy, we don’t even look at the emissions of a Porsche or a Bentley, because they are just dwarfed by the emissions from the big automakers.”
Lovaas thinks that if ticket prices drop, which is the goal, space tourism could become a larger source of pollution. In fact, the business minds behind these schemes hope that eventually, as happened with air travel, suborbital flights will become cheap enough to lure average vacationers. They believe the initial revenues from the high-ticket sales will speed technological advances while decreasing costs overall. If prices drop and space tourism becomes commonplace, environmentalists may one day set their sights on the industry.
However, both Virgin and Xcor say that bringing the masses to space will have surprising benefits. Virgin magnate Richard Branson rhapsodized in a speech about how viewing the Earth from above could transform passengers, a phenomenon called the overview effect. Former astronauts have reported that the sight “helps one to wake up to the fragility of the small portion of the planet’s mass that we inhabit and to the importance of protecting the Earth,” Branson said. Maybe space travel as eco-tourism isn’t such a far out idea.
Story by Eliza Strickland. This article originally appeared in Plenty in August 2008.
Copyright Environ Press 2008.