At 12:00 PM 5/1/2008, Dan wrote wrote: (Keith wrote) >At 12:00 PM 4/17/2008, Dan M wrote: > > (Keith wrote) > > >What do you want? The current 747 cost about $300 million and dry > > > > masses out to about 185 mt or $1.6 million a ton. Produced in > > > > similar tonnage, do you see any reason these rockets would cost more > > > > than per ton than a 747? If so, why? > > > > > >For the rocket itself, not counting all the other expenses associated > > with launches, that's not an unreasonable cost. > > > > Agreement! > >Right, but that's for the rocket itself. Not a shuttle, a rocket.
A rocket in the shape of a space capsule using a water cooled heat shield. 39 tons of water. > > > > The .pdf was recommended as a good reference by Hu Davis of Eagle > > > > Engineering. Look him up. > > > > > >What has he built? > > > > The Eagle as in "the Eagle has landed." > >OK, I asked because I've seen so many "experts" who never had to do things. >He does have great experience leading successful space design teams. So, I >looked up the website of the space company he and Buzz Aldrin are leading > >http://www.spaceandtech.com/spacedata/rlvs/starbooster_sum.shtml > > >From my perspective, this shows the difficulties inherent in reusable craft. >He is not discussing a rocket that can hit near orbit, launch a system to >geocentric orbit, and then re-enter the atmosphere. Rather, he is >presenting a far more modest goal: salvaging the first stage of a present >system. > >The cost of doing this His company has nothing to do with the Neptune rocket he pointed me to. snip >As of two years ago, the owner has spent 100M of his own money, and has had >two failed launches. RDTE for this monster, go look it up, was $24 billion. More than two orders of magnitude more. snip >I think a recoverable, reworkable first stage, with a parachute drop and an >ocean retrieval, might be workable....and save some money in the long run. Out of the question. Water landing, yes, but *fresh* water. >But, re-entry is an extremely harsh environment. Dry yes, wet, no. snip >So, the step which I strongly disagree with is assuming that such a vehicle >can be built for the cost of a disposable rocket. It's not my opinion, take it up with the folks who designed it. I was just taking Hu Davis' stamp of approval. snip > > If you were flying them every day instead of ever 100 days could you > > do it with the same number of people? > >They were suppose to fly once a week...with far fewer people than are needed >to fly them once every 100 days. And yet airlines fly planes several times a day with small crews. How do they do it? Can it be translated to space operations? If not, why not? > > Part of the cost is the very low production rate for spare > > parts. Another big chunk is paper pushing. > >NASA is inefficient, I won't argue with that. But, the fundamental problems >remain. If it were easy, don't you think one of 7 non-NASA groups would >have done something by now? > > > > Some years ago I read that the effort to recover and refurbish the > > segments cost more than just letting them sink. > > > 2000 tons per day is an entirely different model. You can't apply > > much of what we know about government space programs to it. > >But, in areas where costs have dropped like a rock (e.g. computers, big >screen flat panel TVs, etc., we've seen a pattern of price drops funded by >the early implementers. Right now, launching commercial satellites is a >multi-billion dollar industry. A simple 30% price drop for the same >reliability would be a big deal. They are all talking about less than 2 tons to GEO every few months. This is 100 times larger and 10 times per day. Different situation entirely. snip > > What gives you the idea space is harsh? Now a wind generator > > standing in salt water, that's harsh. > >I was referring to my own work. Oil platforms have stood in salt water for >generations. Sea water is not very corrosive. I've had to design for far >worse environments. I beg to differ. Turn off the cathodic protection and how long does it take to fall apart? >My own experience has been with MWD (Measurement While Drilling). Our >standard qualification test is temperature to 175C, 20 g RMS random >vibration for 2 hours in each of the three axis, and 1500 g shock. With >that random vibration one does get the 3 sigma 60 g vibration from time to >time. I am not impressed. Back when I was bonding chips we subjected all of them to 10,000 g in -Z to see if we had any marginal bonds. I don't remember a single time we did. snip > > When power sats are not considered (and they usually are not) then > > you get statements like this: > > > > "No combination of renewable energy systems have the potential to > > generate more than a fraction of the power now being generated > > by fossil fuels." > > -- Jay Hanson > >Nuclear power is a green alternative that's already price competitive >(unless PC demands raise the price artificially). Nuclear power is not a renewable. Without heavy breeding we don't have a lot more uranium than we do coal. snip > > Please don't unless you have some idea that's not been talked about > > before. What I would like is a critical discussion leading to a > > model for a pipeline to GEO large enough to build power sats in large > > numbers at low enough prices to deliver power at the ground bus bars > > at a penny a kWh. If we can do that, we can make synthetic gasoline > > for a dollar a gallon. If we can't, several billion people are > > likely to die in the toboggan ride down the back side of peak oil. > >Why do you think mainstream science is wrong on global warming? It doesn't matter if global warming kills people, they will already be dead from energy related causes. >Why do you >think people will willingly die before using nuclear power? The consequences of using a lot of nuclear power is that lots of people may unwillingly die. There is an unrecognized problem with a lot of reactors and the DU the US scattered around. I.e., we may get it back. See the end notes here: http://www.kuro5hin.org/story/2007/10/30/18253/301 Keith _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
