On 17/04/2008, at 12:26 PM, Dan M wrote: > >> >> So-called supercruise. The biggest problem with going over Mach 1 is >> political and legal, not technological - had Concorde not been killed >> by politics. > > Well, Concord was a political animal from the very beginning wasn't > it? It > was a tax subsidized showcase for Britain and France from the > start. IIRC, > it never really was a profit center.
All aircraft mfrs are subsidised. Yes, it was supposed to be a technology > > >> its successor would have been an "efficient" supersonic plane. > > I don't doubt that a successor would have been better, but you putting > "efficient" in quotes seems to indicate that you aren't arguing > against the > fundamental increase in cost per passenger mile when a plane goes at > Mach > 1.05 compared to Mach 0.95. "Fundamental"? No. Substantial, yes. > That's not political. The decision to use tax > money to subsidize the travel of the richest businessmen is, of > course, > political. The politics came in when a swathe of countries banned the Concorde from overflying. That's what killed it. Didn't take long before the only route for Concorde was the transatlantic shuttle, and even then, only the very rich could afford it. That's a scale issue. When only a handful are ever built, the R&D isn't every going to be repaid. You seem to think the subsidies were aimed towards Concorde's final fate. They weren't, they were aimed at getting the time of long-haul flights down. Even today, it takes a day to get from London to Sydney. Concorde was supposed to halve that. > > >>>> Can you be specific about what you mean here? >>> >>> Sure, to be effective, power would have to be transmitted down in a >>> fairly >>> dense fashion. One needs mechanisms that provide feedback to turn >>> the power >>> off should the aim stray. >> >> Current designs seem to show a wide collection with a diffuse beam, >> so >> that it's relatively safe to be under the beam. > > OK, then there would be the cost of a wider array, It's chicken wire on poles, Dan. Strung over land that can still be used for other stuff. The rectennas are by far the smallest costs in the whole thing... > >> Point on this part is that there is huge inertia when there's huge >> capital expenditure - if you've spent a few tens of millions on a >> plane in 1970 or 1980 you're going to keep using it as long as you >> can, 'cause a similar plane costs a few hundred million in 2008. > > I understand that, but there was a huge inertia ...? > > >> All that said, I'd like to see you, Dan, try to put together a cost- >> analysis on a powersat project. > Nothing works 100% of the time, but lets assume a 95% efficiency, or > running > 8322 hours/year. The cost is, then, about $39 per kWh. Right. So, how do you improve that. OK, say we can get the launch cost halved by mass producing rockets and stuff. That's still $20/kwh. Coal's a few cents a kwh. Even with carbon sequestration doubling or tripling that, it's still a big gap. Roof-mounted solar, I can get a 1kW system (grid connected) for AUD5200, with 20 year warranty. So say it's doing that 1kw 6 hours a day (paper napkin calculation here), that's 43,800 kw across the life of the system, that's about AUD8/kwh ($7.50/kwh). So still a lot better than a powersat, and that's not factoring in the launch pollution. So... how to bridge the gap? Charlie. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
