On Thursday, June 5, 2014 11:32:53 PM UTC+12, Jeff Findley wrote:
In article ,

says...



Because NASA isn't getting enough money!



Bull$****! NASA is being forced to spend money in stupid ways due to

politics.

Agreed - that wasn't the point of my discussion, but its a valid point nevertheless.

It is the nature of political institutions to be political. As Milton Friedman once said, expecting a political institution to be free of politics and the attendant waste that implies is like expecting a cat to bark or a dog to meow.

Bottom line, NASA isn't getting enough money, is a mantra cuts to the chase of what NASA needs to do something. Its not the low cost solution however.. Its only a symptom of NASA being a government agency.

The ONLY way a government agency can do wonderful amazing things is when there is a massive RATE OF INCREASE in spending. Then, they'll spend generations memorializing their wonderful achievement if you let them, as they suck ever more money out the taxpayers. This will continue across the board until the Republic fails, as already happened in the former Soviet Union, is happening in Europe and Japan, and will happen in the USA and China.


SLS/Orion are the poster child for wasteful government
spending designed to spread spending throughout as many key districts as
possible.

Agreed.


Bigger and bigger launch vehicles aren't the answer to everything.

Agreed. Space travel is a complex business. You have to do many things well. Even so, we can look at the highlights needed today.

Highly reusable vehicles, ones that have 20 year working lives, cost less than 0.1% or less their purchase price in maintenance to reuse, and are usable 2,000x or more without compromising safety or reliability - is a critical technical achievement.

However, in concise conversation, bigger and hotter launch vehicles lower the cost of space access more rapidly than anything else, if choices must be made about what to talk about in a 4 minute elevator conversation.

In
particular, developing technologies like inflatable reentry shields is
one of many enabling technologies that helps to eliminate the "need" for
very large launch vehicles for a manned Mars mission.

Inflatable technologies are near and dear to me. I've been a proponent of inflatable technologies for low-cost re-entry and entry into Mars' atmosphere for many years.

Saying we have to ignore one good idea to do another good idea is the fallacy of 'false choice' - there is nothing in inflatable thermal protection gear that makes us not choose to build adequately sized vehicles with high exhaust velocities. (bigger & hotter)

Cryogenic storage
of LH2, LOX, and other cryogenic propellants is another.

Agreed - interestingly that's the 'hotter' side of the equation I mentioned - as far as chemical rockets go - since LOX/LH2 gives a hotter exhaust (and higher exhaust velocities) than LOX/RP1 or N2O4/A-50.

In space
refueling of cryogenics is yet another.

Absolutely correct. If I can refuel my BMW Hydrogen 7 at the pump, there's no reason I shouldn't be able to refuel a hydrogen vehicle in space.

In situ fuel production...

Yes, I've written extensively on that in these posts recently, as well, giving peer reviewed papers on the subject as reference.



The list is seemingly endless,
but each piece, if taken as a small R&D
program, wouldn't be terribly expensive compared to the seemingly
"obvious" alternative of the uber expensive SLS.

Absolutely correct. A natural path toward continuous improvement must be followed. There are a variety of ways this may be done. The scale of the problem is known.

If you take a graduate degree in Aerospace engineering as I have done, you will find there are about 3,000 things you must do well to do space travel. Failure to do ALL of them well, ends up in failure. Alternatively, it gives you about 2,999,000 ways to do a two-way combination of factors to improve things. The ways to organize ALL those factors optimally is very large, not infinite, but larger than the number of subatomic particles in the visible universe.

The only approach that provides sustained progress is an emergent one, which you have outlined one way that can occur. There are others. In fact, the present epoch may not only be replete with failure of the international regime as we have known it, but also known for the rise of emergence as a method of governance.


..




Jeff

--

"the perennial claim that hypersonic airbreathing propulsion would

magically make space launch cheaper is nonsense -- LOX is much cheaper

than advanced airbreathing engines, and so are the tanks to put it in

and the extra thrust to carry it." - Henry Spencer