The Guardian reports that Virgin Galactic’s Will Whitehorn was “hopping mad” over a recent study indicating that SpaceShipTwo might not be as clean as the company claims:
“The research was fundamentally wrong,” he says. “If you had a Virgin Galactic program running for ten years, if you assumed that we weren’t using biobutinol (which we will) we’re talking about less environmental impact over ten years than 1.5 shuttle launches.”
According to this British Petroleum fact sheet, biobutinol is an ethanol-type biofuel that:
- Can be blended into standard grade gasoline or gasoline containing ethanol, is compatible with existing vehicle technology and has the potential to be incorporated into the existing fuel supply infrastructure.
- Can utilize a variety of conventional feedstocks such as sugar cane, sugar beet, corn, wheat, cassava and sorghum, supporting global implementation.
- Will have processes compatible with future biofuel feedstocks such as lignocellulosics from fast-growing energy crops (e.g. grasses) or agricultural byproducts (e.g. corn stalks).
Whitehorn blames the research team lead by Martin Ross of The Aerospace Corporation for putting together a study with bad data:
So why the discrepancy between Aerospace Corporation and Whitehorn’s own environmental assessment? “They never contacted us, and never spoke about the fuel that we were using,” Whitehorn complains. “We are not allowed to discuss because of ITAR rules [International Traffic in Arms Regulations] exactly what the rocket motor was. But we’re not using rubber. We’re using a form of recycled nylon.”
However, The Guardian indicates that Virgin Galactic hasn’t always been clear on what it’s doing:
Virgin Galactic’s own website says that its hybrid engine is using a “rubber compound”, with a nitrous oxide oxidiser, but Whitehorn was quoted as saying that the firm was looking into nylon fuels at the spaceport opening ceremony.
Ross contends that the research team contacted Virgin, and spoke to Whitehorn directly. “We talked to them to get their help and make ground measurements,” he says, adding that the researchers wanted to put instruments on Virgin’s aircraft, and perhaps use video documentation of the launches to observe emissions. “There are a lot of ways that they could help us out and we talked to them, and that communication just ended and so we pressed on,” Ross shrugs. In the absence of mission-specific data, Ross’s team ended up using a generic model for the predictions used in the study…
Ross’s study was complete before the Oct. 22 runway dedication where Whitehorn, in response to a media question, stated that SpaceShipTwo would be using recycled nylon for the first time. This begs the question of what impacts recycled nylon and biobutinol will have on the atmosphere and climate.
The interesting aspect about Ross’s study is that it focused less on greenhouse gas emissions — which have formed the basis of Virgin Galactic’s claims to the environmentally benign nature of SpaceShipTwo — but rather on the particles that will be put into the upper atmosphere, where they could stay for 5-10 years.
But the main point is that these particles have a bigger effect than we imagined, he warns. “Everyone needs to shift their view â€“ and this is one of the main results of the paper â€“ away from gas emissions and towards particle emissions,” he said.
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