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point-to-point passenger flight

Posted by: Ekkehard Augustin - Thu Dec 30, 2004 2:36 pm
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point-to-point passenger flight 
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Post    Posted on: Mon Feb 14, 2005 11:51 pm
I'm going to reply to the poll and say "It won't happen in any way that will be economically important". Let's face it, folks: a rocket is really good at going straight up. You can't get a propellor or turbine engine to do that, because your atmospheric pressure eventually drops too low and you just fall back down. A rocket, on the other hand, does not need any atmospheric pressure: it will chug along just as happily in hard vacuum as it will in the ocean (which is why submarines can launch nuclear missiles).

So rockets can go places conventional engines can't. However, rockets "run rough". Meaning you have to replace the engines a lot more often than you do conventional propellor or turbine engines. Granted that there's practically no moving parts to break, but the temperatures and pressures experienced in a rocket engine take their toll very quickly. Also, you are dealing with exceptionally dangerous fuels. Any one of you: go find some rubbing alcohol (the old 90% stuff that they don't make anymore works best, but the newer, weaker stuff will still do the trick) and pour just a little bit in the bottom of a shallow glass dish. Not too much, just enough to cover the bottom. Place the dish in the bottom of your sink. Stand back a bit (make sure there's nothing flammable nearby), strike a match, and toss it in. Observe. Keep this in mind: this is usually chosen as a prime rocket fuel because it is among the SAFEST and LEAST VOLATILE available. Think about that for a second. Then imagine what would happen if a truckload of that stuff went off in the middle of a busy airport. Aviation gasoline (jet fuel) burns. Big fireball, small shockwave. This stuff blows up. Huge fireball, shockwave to take a wall or two down.

So rocket fuel isn't good stuff, and the engines wear out quickly. So rockets (at least the kind needed to get stuff up out of Earth's gravity well) have a higher operating cost than airplanes. Rockets also make passengers very very uncomfortable for periods of their flight: some people won't go on today's jetliner flights, when you're barely aware of being airborne. Very few will want to experience 4 Gs and the subsequent weightlessness (and then 4 Gs again). Very few indeed -- unless they're trying to get somewhere off-world. On top of that, rockets enter the atmosphere at a very high speed, but then slow down very rapidly. SSO takes 2 hours (I'm pretty sure that's right) to get back to Mojave after it's re-entered the atmosphere. So a suborbital flight, despite the initial high acceleration, is much slower than a conventional flight.

So they're more expensive to run, they scare passengers away, and they take longer. Point-to-point suborbital flight simply isn't all that economically viable.

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Post    Posted on: Tue Feb 15, 2005 2:52 pm
From http://www.sierrafoot.org/x-15/adventur ... tures.html
Pilot Milt Thompson commented that this (X-15) was the only aircraft he'd flown that made him glad when the engine quit. :lol:


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Post    Posted on: Tue Feb 15, 2005 3:16 pm
I am sorry that I don't find time your post, Spacecowboy. You are writing very interesting, carefully, objective and the right way. I will read it later and answer if than if there are reasons.

Sorry for the delay.

Peter,

what you wrote doesn't mean that I am misunderstanding Rutan. I know all that - but what you are describing is called a substitution by economists. The suborbital vehicle under development for Virgin Galactic will be able to go up to 135 km if launched vertically. In this case it would not go a very large distance over surface. If a larger distance over surface is desired it mustn't be launched vertically but less than vertically - and then it wouldn't reach the maximum altitude it is able to. Mor diatnce - less altitude: That's substitution distance for altitude. Not to be launched vertically doesn't mean to be launched less than 45°.

And point-to-point flight doesn't mean transatlantic necessaryly. And perception doesn't require transatlantic nor does it require to be economical - we are not talking about demand or actual demand...



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Tue Feb 15, 2005 7:54 pm
Ekkehard Augustin wrote:
Branson/Rutan will offer such flights for fun - but from this and the experiences made by it perhaps the idea might come to their minds or to one of their rich passengers and tourists to provide services this way that are provided by airlines as Thomas Cook, Lufthansa, British Airways, Lauda Air etc. today.

This sure sounds like you are talking about commercial transport primarily for getting somewhere and not just for the thrill of going suborbital.
Ekkehard Augustin wrote:
we are not talking about demand or actual demand

Then what are we talking about?


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Post    Posted on: Wed Feb 16, 2005 12:05 pm
We are talking about perception and perception is very different from demand.

For example - as I explained earlier - I perceive airplane flights from Hamburg to Frankfurt at the Main but I don't demand them - I never bought a ticket and I am not going to do that. The reasons are similar to Andy Hill's business men-argument.

Another example are nuclear reactors for generation of electricity - I perceive them but I don't demand them: they are demanded by the electricity producing industry. And the majority of the general public in Germany long before the elections for our federal parlament "Deutscher Bundestag" ceased to perceive nuclear energy but the electricity indsutry continued to demand the nuclear reactors. This example shows that even the perceiving persons may be quite other persons than the demanding persons..

We are talking about perception and the example show that perception is very different from demand.

Concerning what you are writing initially: Yes, I'm NOT talking about the thrill or the thrill-seekers. I am talking about something that may evolve out of that what Rutan say is possible by the vehicles for Virgin Galactic. And these vehicles may cause the perception for that what may evolve because they can be used for point-to-point flights.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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