Space Journalist/Blogger Rob Coppinger wrote an article tonight attempting to debunk “The Fantasy of Propellant Depots“, which he makes out to be some sort of religious mantra in the New Space community. I will admit that depots are finally starting to get a tiny bit of the attention they deserve, but that has only been within the past year or two, so calling it a religious tenet seems like a bit of a stretch.
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If the depot is commercial, and in an inclination where it can buy from the cheapest suppliers, you might be able to do such a mission at a far lower cost than you could launching it on a Delta-IVH. With a propellant depot, even stages as small as the Falcon I upper stage can put sizeable payloads into lunar orbit."
http://selenianboondocks.com/2008/11/the-fantasy-of-propellant-depots/

Linked from http://www.transterrestrial.com/
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"Propellant Depot Dreams
By Rand Simberg on November 20, 2008 6:58 AM
Categories: Space

Rob Coppinger says that they are in fact, a fantasy (though he doesn't explain why they require "unobtainium").

Clark Lindsey ably responds. I think that there are several problems with Rob's thesis, but don't have the time to get into it right now..."