Travel has long had an environmental cost: gasoline, jet fuel, spandex pants for bicycling. With space tourism soon to become a common occurrence, what will be the environmental price?
Nobody likes thinking about the environmental impact of space travel. The environmental movement is admirable, but it's tied to unstinting realism — you can't have everything. You have to moderate packaging, energy use, living space, and modes of travel. Everything has a cost, and that cost has to be minimized, even though it can't be eliminated. Meanwhile, space travel lends itself to the excesses of the imagination. It's an endless universe full of new worlds and possibilities. One of those possibilities — tourists heading off into space — seems close to coming true.
It's an exceptional experience, but it's no different from any other hit to the environment. Getting a craft and a group of people up into space on a daily basis has to consume energy and leave waste in its place. How bad is it going to be?
Virgin Galactic has made plenty of noises about minimizing the damage. By eschewing a typical launch and having its space craft piggy-backing on a 'mother ship' that takes off from a runway, the company will cut energy costs. (Other potential space craft manufacturers are building super-lightweight space craft or having their craft towed upwards by helium balloons to minimize the need for fuel.) The hangar for the space craft will have solar panels and use passive cooling. The mother ship's engines have the capacity to run on biofuel, although right now they don't. And Virgin is practicing direct monetary expiation, investing $3 billion in green technology.
In the end, though, a flight to space is a flight to space, and it will have an impact. According to the American Geophysical Union, 1000 space flights per year could raise the temperature in Antarctica 0.8°C all on their own. The soot deposited by the space craft in the stratosphere runs the risk of becoming a permanent atmospheric feature. Regular space flights would deposit that soot in the atmosphere, the earth rotates under it, and a band of carbon hangs permanently over that latitude. Not only will it cool that entire section of the globe by as much as 0.7°C, it will alter all the weather patterns around it. These in turn will alter others, and the world will change. All for a few thousand people getting to enjoy a suborbital flight.
This prediction was met with protests that many of the figures used in its estimates were too high, particularly the estimated amount of fuel. However, there is no doubt that commercial space travel will have environmental consequences. Everything costs. A day trip to space could cost more than we might be willing to pay.