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Random Ideas

Posted by: Horus - Thu Oct 18, 2007 2:01 am
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Post    Posted on: Wed Nov 14, 2007 4:48 am
I'm fairly new to this forum as well but can't resist throwing in my 2 cents worth. (Well it's a long post. It may only be worth one cent.)

It seems to me that somewhere in the last 20 years we went past the point where space activity passed from being something a few governments did to being an inevitable progression to an inter planetary society (barring total social catastrophy, of course.)

The point is people are now making money out of space.

If you are a broadcast company wanting to provide a satellite service it's totally economic to purchase a satellite, a launcher, and you're in business. Hey, it's expensive, but it's practical. There are no subsidies from governments to keep the companies doing this afloat. It's just business.

So there is a business in space. Russian, Europe and India see this and have commercial launch programs.

Ironically the US launch providers are so grafted onto the government teat they do not see this emerging market as worthwhile and are no longer competative in the market. This is extremely short sighted, because the government can only ever be one customer, and a business that relies on just one customer is in trouble.

Over the next 20 years competition between launchers will begin to drive down prices. SpaceX is the start of this.
Other Space Companies will see niche markets providing bits of infrastructure. Bigelow with orbital faculities. Some other companies with space tugs, Lunar transfer vehicles or what ever else it is that the market wants.

And because of this infrastructure business opportunities will grow. Perhaps space based solar power. Perhaps on orbit construction of bigger communication sats. Perhaps space tourism. And certainly some things we haven't thought of yet.

But all these opportunities will be commercial.

Over the next twenty years we will see the building up of a space infrastructure and with it new business opportunities.

And at some point in the next twenty years space investment will move from being something business will barely consider to the new business boom frontier.

Then all of a sudden we will be looking for some of these new technologies. But not till then.
Fred

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Post    Posted on: Tue Jan 29, 2008 1:10 am
Its a chicken and the egg dilema. To attract business the launch costs must go down and for the laucnh cost to come down there must be business competition, which there ain't cause of the high lauch costs and the goverment monopoly on space lauchers. Personally I think arms race and not business will drive innovation in space for quite some time. I think it is no coincedence that decline of space industry coincided with ratification of comprehensive test ban treaty and outer space treaty. Given the recent trouble and militaristic shift of USA foreign policy and ineventable knock on effects on other nations, I think the future of space industry is bright for the decades to come. Stepping stone toward a reusable space plane is a hypersonic scramjet. Once you build a Mach 15 bomber, it is easy to equip it with a playload single stage rocket that will go to LEO instead of enemy target witt a reasonable mass ratio. Since the scramjet is reusabe the space lauch costs will go down by orders of magnitude.

The trouble with business driving invention that many of the business schemes would become viable only if the lauch costs are about 100$/kg which is roughly two orders of magnitude cheaper than it is today. You need applications that are viable at 1000$/kg as a stepping stone. I believe that space weapon platforms are one of such application. Now the challenge is not to cause preemptive nuke strike before the "Star Wars" constellation is put in orbit.

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Post    Posted on: Tue Jan 29, 2008 8:39 am
Hello, Horus,

please think of SpaceX and their launch prices, of t/Space and of Scaled Composites. SpaceX is actually a strong private competitor driving costs down, t/Space is a potential competitor yet but potential competition has strong impacts for reasons that can be shown up by the Theory of Competition as part of Political Economics. Burt Rutan of Scaled Composites has been quoted to have said that WK2 can launch a manned vehicle carrying one person - this also is potential competition and easier and more quickly turnable into actual competition.

So the chances that launch costs come down are really good.



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


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Post    Posted on: Mon Feb 04, 2008 1:42 am
I was browsing my eng. notebook the other day and stumbled upon ramjet/scramjet Isp performance vs Mach speed. So just to kill time I run a few back of the envelope calc. to check the viability of two_stages_to_orbit atmo breather.
So... lets say the first stage is a 100t loaded hypersonic plane that uses cyclic ramjet/scramjet engine (meaning its' engines can run both in ramjet and scramjet mode) that runs on aircraft fuel. Now it engines need to get to Mach 1 plus to start working, so the obvious solution is to store some LO2/fuel mixture to run the engines in the rocket mode. The weight of LO2/fuel is:
100-((e^0.35/3.5)^-1*100t)=10t
After Mach 1 performance of ramjet/scramjet varies depending on speed but for simplicity I assume that Isp is 1000s up to Mach 12. So to accellerate to Mach 12 you need:
100-((e^3.67/10)^-1*100t)=31t of fuel

Assuming the plane weights 25t plus 10t for rocket stage accelleration plust 31t for fuel and another 4t for manuver fuel we get 30t playload stage.
Now the second stage is an expendable single stage kerosine rocket (Isp=350s), the plane opens its' bay doors and lets second stage to freefall for a time and then the second stage ignites. To get from Mach 12 (4km/s) to LEO you need extra 5km/s Delta V. So the mass ratio using kerosine rocket would be about 4 so our dry weight+playload would be:
30*0.25=7.5
Depending on dry mass ratio this would mean that the playload is anywhere from 4t to 6t.

So it appears that two stage to orbit scheme is viable... at least theoretically.

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