Constellations, Launch, New Space and more…

It’s Not Easy Being Green….

By Doug Messier
Parabolic Arc
August 15, 2008
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Plenty Magazine has a piece about the race to build a suborbital rocketship that is a green, or at least one that is “environmentally benign” – whatever that means. Eliza Strickland interviews XCor’s Doug Graham and Virgin Galactic’s Stephen Attenborough about their companies’ efforts.

“[Xcor] 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,”  Strickland writes. “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, on the other hand, is promoting how environmentally friendly its tiny spaceship is compared to the massive jumbo jets it flies across the Atlantic daily.

“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.”

This is a bit like comparing apples and peanuts – in terms of vehicle sizes, distances covered, payload weights, number of passengers, and just about every other objective measure imaginable. SpaceShipTwo really doesn’t go anywhere; it takes off and lands at the same airport. It’s not a point-to-point transportation vehicle.

This all strikes me as rather dubious – an effort to justify what many consider to be a frivilous activity based on questionable comparisons.

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