Richard Branson has been touting the arrival of Space tourism- a 15 minutes ride to the edge of space for an estimated price of $200,000. As exciting as the offer is for many millionaires and billionaires (and of course the obnoxious, super rich Real Housewives of Beverly Hills, California & New York), many don’t realize how environmentally damaging this form of entertainment(!) could be to the Earth’s atmosphere.
This Time.com article has put a great emphasis on the impacts of this budding form of tourism. Given the rate of evolution of our propulsion technologies of today, it might be a while before we find a way to get to space without sullying the atmosphere. Of course, this is apart from Space debris, asteroids, and all other issues threating to wipe the Humanity off the earth.
Launching rockets can be either a very, very dirty business or a pretty clean one, depending on the kind of fuel you use. The shuttle’s solid boosters are filled with a rubbery mix made up of ammonium perchlorate, aluminum, iron oxide, epoxy and a polymer bonding agent. If you think setting all that on fire would produce some nasty exhaust, you’re right. The Saturn V moon rockets used a mix of kerosene and liquid oxygen in their first stages, which produced it’s own air-fouling smoke. The second and third stages, however, were fueled with liquid oxygen and liquid hydrogen, releasing mostly flame and steam. The rockets that would be used for launching tourists on suborbital missions would be filled with some kind of hydrocarbon fuel which, like the kerosene in the Saturn V, would act as a pollutant.
To conduct its calculations on the atmospheric impact of recreational rocketry, the AGU proceeded on the assumption that the space tourism industry is correct when it projects that it will be launching about 1,000 vacation rockets per year by 2020. That’s not an entirely unreasonable prediction since Branson is by no means the only entrepreneur in the game. If that ambitious goal is met, the first and biggest concern would be the amount of soot the engines would produce. One thousand commercial launches would produce 10 times the soot emitted by government and private rockets today—and that presents serious problems.
Since particles of soot are black, they absorb rather than reflect away heat and light. Soot from rockets poses a special danger since it is emitted far higher in the atmosphere than 0ther sources of air pollution. “Rockets are the only direct source of human-produced compounds above 14 miles [22.5 km],” said the paper’s chief author Martin Ross in a statement.
In the case of vacation rockets, this would mean a layer of accumulated soot in the stratosphere about 25 miles (40 km) high, or three times the altitude at which commercial airlines fly. The AGU’s computer models showed that by blocking sunlight, the soot could actually cool much of the surface of the planet by 1.2ºF (.7ºC), which seems like a good thing in the face of global warming. However, it would warm Antarctica by 1.5ºF (.7ºC), which is exactly what the rapidly melting southern ice does not need. Worse, soot that’s been deposited 25 miles high can hang around in the atmosphere for years, unlike soot from factories, coal-fired power plants and airliners, which precipitates out in as little as a few days or as much as a few weeks, depending on quantities and circulation patterns.