Calculating Environmental Damage From Space Tourism Rockets 83
MithrandirAgain writes "A new study from several scientists at the Aerospace Corporation claims spaceships that rely on rubber-based fuel could help cause climate change. The fuel apparently expels a black carbon soot into the stratosphere when burned with nitrous oxide, which could be contributing to global climate changes, like shrinking the icecaps. However, the authors are careful about their work being an end-all study and are 'inviting others to take a look.' Virgin Galactic, whose SpaceShipTwo just made its first solo flight (and uses the type of fuel discussed in the study), is listening to the scientists' concerns. CEO George Whitesides said, 'I think we and others in the industry welcome the opportunity to talk about all of these issues.' SpaceShipTwo does use a hybrid engine 'because of its significantly lower environmental impact than other designs,' and Whitesides stresses, 'I think as we look at this more, we'll find the impact will be far smaller than that set out in the paper. In any case, I welcome the conversation.'"
Nice attitude, but the real reaon for the motor... (Score:5, Informative)
The reason they went with this motor design was simplicity of construction, low chance of explosions and other nasty failure modes, reliability and price. Yet another is that this motor type can be shut off before the burn is complete (unlike the SpaceShuttle side boosters which use a thermite-like mixture (with a rubber-like binder) which provides its own oxidizer.
The Rutan design uses nitrous oxide as an oxidizer to be able to better control the burn.
I don't recall environmental factors being discussed when Rutan and co. were publicizing the motor design.
The engineering reasons are perfectly good, though, and research into figuring out a blend which spews out less soot would probably be good from all standpoints (possibly even upping the specific energy content of the motor/fuel)
The reporting bugs me (Score:4, Informative)
Re:Why warming and not cooling? (Score:3, Informative)
Re:Why warming and not cooling? (Score:5, Informative)
To oversimplify:
Volcanoes generally release sulfate aerosols -- tiny clear droplets of sulfuric acid -- and pale grey ash particles. These are lighter in color than the ground below them, so adding them to the atmosphere makes the planet as a whole lighter in color, so it reflects more sunlight, causing cooling.
Black soot is black: adding it to the atmosphere *darkens* the planet overall, causing it to heat up.
Re:How about the impact of plain tourism first? (Score:4, Informative)
A very important distinction: planes, ships, and buses are designed to run clean, with little or no soot output. They also operate in the troposphere, where rainfall "washes" the atmosphere and cleans out the soot and other particles regularly. This is a very different thing than NO+rubber rockets (which are literally as clean-burning as a burning tire) in the stratosphere, where small particles tend to linger for years.