RSS iconTwitter iconFacebook icon

The Trek BBS title image

The Trek BBS statistics

Threads: 138,364
Posts: 5,356,000
Members: 24,625
Currently online: 616
Newest member: 3d gird

TrekToday headlines

Borg Cube Fridge
By: T'Bonz on Jul 29

Free Enterprise Kickstarter
By: T'Bonz on Jul 29

Siddig To Join Game Of Thrones
By: T'Bonz on Jul 29

Sci-Fried To Release New Album
By: T'Bonz on Jul 28

Star Trek/Planet of the Apes Crossover
By: T'Bonz on Jul 28

Star Trek into Darkness Soundtrack
By: T'Bonz on Jul 28

Horse 1, Shatner 0
By: T'Bonz on Jul 28

Drexler TV Alert
By: T'Bonz on Jul 26

Retro Review: His Way
By: Michelle on Jul 26

MicroWarriors Releases Next Week
By: T'Bonz on Jul 25


Welcome! The Trek BBS is the number one place to chat about Star Trek with like-minded fans. Please login to see our full range of forums as well as the ability to send and receive private messages, track your favourite topics and of course join in the discussions.

If you are a new visitor, join us for free. If you are an existing member please login below. Note: for members who joined under our old messageboard system, please login with your display name not your login name.


Go Back   The Trek BBS > Entertainment & Interests > Science and Technology

Science and Technology "Somewhere, something incredible is waiting to be known." - Carl Sagan.

Reply
 
Thread Tools
Old October 9 2012, 01:01 AM   #211
sojourner
Vice Admiral
 
sojourner's Avatar
 
Location: I'm at WKRP
Re: Envisioning the world of 2100

publiusr wrote: View Post
sojourner wrote: View Post

When NASA is involved in telling how to build and run a system all you get is cost over runs and power point spaceships.
The contractor isn't supposed to tell the buyer what he needs.
Pleas tell me where I said they should?. The contractor is there to provide a service. NASA shouldn't be telling them how to build and run that service.
__________________
Baby, you and me were never meant to be, just maybe think of me once in a while...
sojourner is online now   Reply With Quote
Old October 9 2012, 02:08 AM   #212
gturner
Admiral
 
Location: Kentucky
Re: Envisioning the world of 2100

publiusr wrote: View Post
They still have ULA to worry about--and in the same way they went after Ares Constellation--they are going after Musk. The October 1 2012 issue of Aviation week has a cover story on Dream Chaser with loads of private spaceflight coverage. Sadly, there was a nasty little op-ed piece on page 10 called "FALCON 9 CALLED INTO QUESTION." I believe this was the same guy who also called RS-68 inefficient. He called Falcon aerodynamically unstable--which I don't buy--then fusses about thousands of pounds of unused kerosene due to the engines 2.2 mixture ration when 3.45 would be better. The fuel rich mixture allows for cheap engines.
Um, that's idiocy nested several levels deep. For one, the design mixture ratio doesn't have any effect on residual fuel because you don't load more than you need, and you design the tanks to hold what you'll load.

The F-1 and RS-27 on the Delta and Atlas used the same mixture ratio as the Merlin, about 2.2:1, which gives close to the optimal specific impulse for most pressure ratios but with a much lower nozzle exit tempertaure (for 1000 psi sea-level, 1900K at 2.2:1 vs. 2300K at 2.5:1 vs. 2500K at 2.7:1) and a lower chamber temperature (3550K at 2.2:1 vs 3700K at 2.7:1). I don't know that anyone has ever even tried running at a 3.45:1 mixture ratio because the specific impulse would be significantly lower (280 vs 300, for example) as would the exhaust velocity. Those are guestimates because I've never seen an RP-1 mixture chart that went past a mixture ratio of 3:1.

The RD-180 uses a mixture ratio of 2.7:1, but it makes the pre-burner difficult to make because it has to run in a high temperature oxidizing environment.
gturner is offline   Reply With Quote
Old October 9 2012, 05:31 AM   #213
Crazy Eddie
Rear Admiral
 
Crazy Eddie's Avatar
 
Location: I'm in your ___, ___ing your ___
Re: Envisioning the world of 2100

publiusr wrote: View Post
sojourner wrote: View Post

When NASA is involved in telling how to build and run a system all you get is cost over runs and power point spaceships.
The contractor isn't supposed to tell the buyer what he needs.
Sometimes he is. When you hire a guy to fix your air conditioning, you are implicitly trusting him to diagnose and solve problems using expertise that he possesses and you do not. When you hire a guy to fix your car, you do so on the assumption that he has a greater capability to perform those repairs than you do.

The whole point of hiring a contractor is because you don't have the capability to do the work on your own. In this case, NASA is a bit like a stubborn do-it-yourselfer with a blown headgasket who has taken it upon himself to disassemble and repair the engine himself. Everyone watching this knows it's going to end badly; the last time he overhauled that engine it cost him four thousand dollars worth of extra parts and took him a month longer than it should have.

Of course, he's not going to listen to everyone, because he keeps telling himself "No problem, I used to do this in the 60s all the time."

newtype_alpha wrote: View Post
That's the biggest argument against Heavy Lift I've ever seen. After all, any given HLV with specs like the SLS is going to be hemorrhaging money.
That is true with any space endeavor at first.
Nobody claimed otherwise. The problem with SLS is that it will REMAIN true pretty much indefinitely, for the simple fact that by the time SLS develops a flight rate high enough or an operating cost low enough to be feasible for commercial operators, the industry will have already adapted and standardized around cheaper alternatives.

And that's assuming the SLS will ever reduce its costs or increase its flight rate; that is an assumption NO ONE is making, in fact the broader consensus is that NASA's projections on the SLS' future readiness are a best case scenario.

You yourself have stated again and again that the aerospace industry is not very good at coordinating long-term plans... so what makes you think anyone in the aerospace industry is going to start planning space missions that depend on the SLS?

Musk operated at a loss
Hell, my mother operated at a loss when she started her first business. That's what usually happens with startup companies until their business case matures.

Again, the point is that the SLS will operate at a loss FOREVER. It will never be profitable because it isn't designed to be profitable; it isn't the kind of thing that any serious businessman would try to build.

You doubted me when I said Griffin wrote AIAA textbooks
No I didn't. I questioned whether or not it was relevant to this discussion. Which it isn't.

The AIAA doesn't have fools write textbooks.
Then why did they have Griffin write one?

Well to say that nobody wants SLS is just not true. ULA knows that NASA didn't want the EELV albatross on their neck, so they put all this anti-HLV nonsense out.
The anti-HLV "nonsense" isn't coming from ULA. It's coming from people who -- unlike you, apparently -- are capable of looking at the history of spaceflight, of air travel, of industry and government, seeing the relevant patterns, and thinking for themselves. The proponents of EELVs just happen to be on the right side of this pattern, but EELVs aren't the ONLY alternative, nor are they even the BEST alternative.

More to the point: the kinds of people who want the SLS program are the kinds of people who have proven an inability to set coherent priorities for spaceflight (Griffin) people who want it for purely political reasons (Sen Hutchinson/Nelson) and people who simply can't conceive of any other way of doing things (Armstrong and Aldrin).

Meanwhile, NASA has failed to preserve -- in ANY PART -- the functionality provided by the space shuttle; private industry has already stepped in to take up the slack. What, then, prevents private industry from eventually displacing the SLS?

The whole depot libration point deal that folks are carping on now...
Was originally NASA's idea from the 1990s. For someone who quotes so many AV-week articles, I'm amazed you didn't realize that.

Life cycle costs on F-35 are going to be over a trillion dollars. That's where I would focus on cuts.
Which ignores the fact that the United States does not need the mission capability provided by the F-35; a fighter aircraft half as expensive with a third of its capabilities would more than suffice if deployed in sufficient numbers, which even the super-advanced F-35 never will be.

Letting politicians define the capabilities of a new system... it's like handing a credit card to a teenage girl and saying "Go buy yourself a car."

Space X's Falcon Heavy isn't needed for just comsats but for BEO use--and is an entry level HLV--and in house--so it isn't just about profits with him.
Not JUST about profits, no. But Musk isn't doing it for free either.

They still have ULA to worry about
Not unless they figure out a way to double the performance of the Delta-IV Heavy. Otherwise, ULA has its government satellite contracts and SpaceX has an obscenely long launch manifest of its own. It's a booming industry, and it's likely to get bigger once the rockets really start flying.

The October 1 2012 issue of Aviation week
Is thoroughly irrelevant.
__________________
The Complete Illustrated Guide to Starfleet - Online Now!
Crazy Eddie is offline   Reply With Quote
Old October 11 2012, 02:34 PM   #214
RAMA
Vice Admiral
 
RAMA's Avatar
 
Location: NJ, USA
Re: Envisioning the world of 2100

Ghostavo Fring wrote: View Post
I can't speak for STR, but I expect energy and resource crises to put the brakes on this "exponential growth" idea. What we are doing is simply not sustainable, and any notion that we will reach the Singularity in time to avoid the effects of such shortages is little more than fantasy.

Actually I've posted on this before, there are no energy shortages, never will be, resources abound in this solar system...dire prediction never take variables of future development into account and are therefore generally useless, other than to spur motivated, active individuals to work on it, and plenty of organizations are doing what gov'ts are slow to.

RAMA
__________________
It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring. Carl Sagan
RAMA is online now   Reply With Quote
Old October 11 2012, 02:46 PM   #215
Robert Maxwell
Respect the Beef
 
Robert Maxwell's Avatar
 
Location: Right behind you!
View Robert Maxwell's Twitter Profile Send a message via ICQ to Robert Maxwell Send a message via AIM to Robert Maxwell Send a message via Windows Live Messenger to Robert Maxwell Send a message via Yahoo to Robert Maxwell
Re: Envisioning the world of 2100

RAMA wrote: View Post
Ghostavo Fring wrote: View Post
I can't speak for STR, but I expect energy and resource crises to put the brakes on this "exponential growth" idea. What we are doing is simply not sustainable, and any notion that we will reach the Singularity in time to avoid the effects of such shortages is little more than fantasy.

Actually I've posted on this before, there are no energy shortages, never will be, resources abound in this solar system...dire prediction never take variables of future development into account and are therefore generally useless, other than to spur motivated, active individuals to work on it, and plenty of organizations are doing what gov'ts are slow to.

RAMA
That is a fantasy.

It is not economically viable to harvest resources from beyond Earth. Not now, and probably not for a long while. We still have a lot of resources to exploit here on Earth. But I notice you said resources, not energy. Those are not the same thing. The fact is, fossil fuels are a limited energy resource, and we are using them up. The alternatives we have aren't that great. They are getting better, but it's clear that the energy advantages we got from fossil fuels are going to vanish once those are used up. And there are some that we may not fully use up because to do so would be environmentally destructive. There are already emerging problems with hydraulic fracturing, and while the US has tremendous amounts of coal, coal mining is still a very dirty and dangerous business--not to mention the fact that we blow up mountains to get at it.

Your attitude is really the whole problem. "Don't worry, somebody will find a solution in time." Unless they don't.
__________________
"Holy shit! It's Beef Supreme!"
The Journeyman - Buy it now! Maybe?
My world simulation project!
My blog
Robert Maxwell is online now   Reply With Quote
Old October 11 2012, 03:10 PM   #216
RAMA
Vice Admiral
 
RAMA's Avatar
 
Location: NJ, USA
Re: Envisioning the world of 2100

Ghostavo Fring wrote: View Post
RAMA wrote: View Post
Ghostavo Fring wrote: View Post
I can't speak for STR, but I expect energy and resource crises to put the brakes on this "exponential growth" idea. What we are doing is simply not sustainable, and any notion that we will reach the Singularity in time to avoid the effects of such shortages is little more than fantasy.

Actually I've posted on this before, there are no energy shortages, never will be, resources abound in this solar system...dire prediction never take variables of future development into account and are therefore generally useless, other than to spur motivated, active individuals to work on it, and plenty of organizations are doing what gov'ts are slow to.

RAMA
That is a fantasy.

It is not economically viable to harvest resources from beyond Earth. Not now, and probably not for a long while. We still have a lot of resources to exploit here on Earth. But I notice you said resources, not energy. Those are not the same thing. The fact is, fossil fuels are a limited energy resource, and we are using them up. The alternatives we have aren't that great. They are getting better, but it's clear that the energy advantages we got from fossil fuels are going to vanish once those are used up. And there are some that we may not fully use up because to do so would be environmentally destructive. There are already emerging problems with hydraulic fracturing, and while the US has tremendous amounts of coal, coal mining is still a very dirty and dangerous business--not to mention the fact that we blow up mountains to get at it.

Your attitude is really the whole problem. "Don't worry, somebody will find a solution in time." Unless they don't.

AH you are mistaken, energy sources AND resources. Resources will not be economically feasible till there are actually efforts to gather it, hence current projects the may be able to tap into asteroid mining, when it becomes more common, prices go down, simple.

As for energy sources, even without lifting another finger we have the greatest energy source we can imagine 93 million miles away, if we absorb only a fraction of it's energy radiated to our planet we can power the whole Earth easily, nano-materials, and energy storage technologies are booming....now if we really want to work at it, fusion and generation IV nuclear fission technologies can also supply tremendous power, and before the scare tactic energy shortage dates predicted by the scaremongers. No one can even agree when "peak oil" is.

It's not pie in the sky, it's happening, nations are turning to solar (even the plodding gov't all over the world now have subsidies for solar, and all sorts of perks for adopting it), the technology and materials industries are booming, ITER and it's follow up are funded and planned. You can refer to the other threads in the technology forum where I have discussed these at length before earlier in the year, if anything the march of progress in all these areas has exploded since then.

RAMA
__________________
It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring. Carl Sagan
RAMA is online now   Reply With Quote
Old October 11 2012, 03:23 PM   #217
Robert Maxwell
Respect the Beef
 
Robert Maxwell's Avatar
 
Location: Right behind you!
View Robert Maxwell's Twitter Profile Send a message via ICQ to Robert Maxwell Send a message via AIM to Robert Maxwell Send a message via Windows Live Messenger to Robert Maxwell Send a message via Yahoo to Robert Maxwell
Re: Envisioning the world of 2100

And yet investment in fossil fuel development continues to go up, not down. That undercuts your entire premise.

As for peak oil--US oil production peaked about 30 years ago. It's ticking up now, but global production is nearly flat. We're looking at more of a "plateau oil" scenario.
__________________
"Holy shit! It's Beef Supreme!"
The Journeyman - Buy it now! Maybe?
My world simulation project!
My blog
Robert Maxwell is online now   Reply With Quote
Old October 11 2012, 04:47 PM   #218
gturner
Admiral
 
Location: Kentucky
Re: Envisioning the world of 2100

Ghostavo Fring wrote: View Post
There are already emerging problems with hydraulic fracturing, and while the US has tremendous amounts of coal, coal mining is still a very dirty and dangerous business--not to mention the fact that we blow up mountains to get at it.
What problems have arisen with fracking? So far where it's used it's produced tremendous gains in production, such as the Texas Eagle field and the Bakken Shale, not to mention all the natural gas fields. With it, Poland can probably replace Russia as the new source of European natural gas.
gturner is offline   Reply With Quote
Old October 12 2012, 08:16 PM   #219
Crazy Eddie
Rear Admiral
 
Crazy Eddie's Avatar
 
Location: I'm in your ___, ___ing your ___
Re: Envisioning the world of 2100

And now the OTHER Sci-Tech poster shows up to push his pet philosophy.

RAMA wrote: View Post
As for energy sources, even without lifting another finger we have the greatest energy source we can imagine 93 million miles away, if we absorb only a fraction of it's energy radiated to our planet we can power the whole Earth easily, nano-materials, and energy storage technologies are booming...
Funny you mention that: it turns out the materials that work best for the construction of solar cells are ALSO limited resources. Polysilicon solar cells are hard to make and expensive to work with and pose a discrete environmental hazard if not disposed of properly. More importantly, current commercial solar cells aren't efficient enough to be competitive with fossil fuels; gallium arsenide cells might, but those are even more expensive and gallium is relatively scarce.

Hydrogen fuel cells? Technical gimmicks aside, those will not be economically viable until we can locate a plentiful source of platinum. Platinum, mind you, is one of the rarest substances on the planet; all the platinum ever mined out of the Earth's crust wouldn't fill my son's bedroom.

It's not pie in the sky, it's happening
It's happening experimentally. No one is spending serious money on it yet, and they won't until there's a major paradigm shift in the global power structure. Until then, it's more worth everyone's while to maximize profits in the paradigm that exists now, since -- as even you pointed out -- nobody has any idea when that will change.
__________________
The Complete Illustrated Guide to Starfleet - Online Now!
Crazy Eddie is offline   Reply With Quote
Old October 12 2012, 08:18 PM   #220
Crazy Eddie
Rear Admiral
 
Crazy Eddie's Avatar
 
Location: I'm in your ___, ___ing your ___
Re: Envisioning the world of 2100

gturner wrote: View Post
Ghostavo Fring wrote: View Post
There are already emerging problems with hydraulic fracturing, and while the US has tremendous amounts of coal, coal mining is still a very dirty and dangerous business--not to mention the fact that we blow up mountains to get at it.
What problems have arisen with fracking? So far where it's used it's produced tremendous gains in production, such as the Texas Eagle field and the Bakken Shale, not to mention all the natural gas fields. With it, Poland can probably replace Russia as the new source of European natural gas.
Some pretty severe and potentially catastrophic environmental consequences if it isn't done properly. Which is a shame, because I'm told it is difficult (read "expensive") to do properly.
__________________
The Complete Illustrated Guide to Starfleet - Online Now!
Crazy Eddie is offline   Reply With Quote
Old October 12 2012, 08:58 PM   #221
gturner
Admiral
 
Location: Kentucky
Re: Envisioning the world of 2100

I live in a house full of geologists, and none of them can come up with a minor consequence, much less a major one, because it just consists of pumping water, brine, sand, and other cheap stuff into rock strata that's already filled with water, brine, sand, and toxic sludge (aka oil and gas deposits) to fracture deep rock layers that already frequently fracture due to geologic forces. Most reserves are still found because the oil and gas is already leaking all the way to the surface through existing fractures.

Some worry about natural gas leaking into water wells, but water wells are so full of natural gas that well drillers have always treated them as natural gas hazards and cisterns have always been vented to prevent explosions.
gturner is offline   Reply With Quote
Old October 12 2012, 10:12 PM   #222
publiusr
Commodore
 
Re: Envisioning the world of 2100

Now I seem to remember a mud volcano that might have been triggered by extraction. Earthquakes might actually be eased by lubricating faults to allow less tension to build up leading to greater quakes.

We are going to have fracking at some level.

Right now we get helium from natural gas wells, and we are running out of that.
Personally, I would support lawsuit protection to allow kids birthday balloons to be hydrogen. If a kid blows his face up--well, he can do that with Dad's Everclear just as well.

Helium must be had for cryogenic research, so we are going to have to use that and be able to get more, I hope. My position puts me at odds with Greens and conservatives in that I support drilling and market restrictions. So be it. The worst implement humans ever used against this planet is not the drill bit, but the plow.

gturner wrote: View Post
Most reserves are still found because the oil and gas is already leaking all the way to the surface through existing fractures.
Very true--
http://discovermagazine.com/2008/jul...know-about-oil

Most of Earth's oil has already leaked to the surface. Around the time of Deepwater Horizon, Wood's Hole found this:
http://www.whoi.edu/oilinocean/page....&article=73106


newtype_alpha wrote: View Post
And now the OTHER Sci-Tech poster shows up to push his pet philosophy.
There is no need to get ugly. I respect anyone trying to get industry off world.

newtype_alpha wrote: View Post

You yourself have stated again and again that the aerospace industry is not very good at coordinating long-term plans...
The shuttle derived crowd has always been on the outside looking in--wanting something tried and true. Venture Star should have suffered the ire aimed now at SLS which is far simpler.

newtype_alpha wrote: View Post
SLS...will never be profitable because it isn't designed to be profitable; it isn't the kind of thing that any serious businessman would try to build.
NASA shouldn't be run by businessmen--that was my point all along--or they would have bailed on Webb.

It isn't about profit man--that's your hang up.

HLV proponents are the ones capable of looking at the history of spaceflight, yet you come up with ad hom' arguements like these:

newtype_alpha wrote: View Post
The kinds of people who want the SLS program are the kinds of people who have proven an inability to set coherent priorities for spaceflight (Griffin) people who want it for purely political reasons (Sen Hutchinson/Nelson) and people who simply can't conceive of any other way of doing things (Armstrong and Aldrin).
So I'm supposed to think your word is worth more than theirs? Hardly. Nelsons district will get space money no matter what rocket is used. EELVs--Delta IV anyway--are made in my home state, and I think a lot of Griffins priorities of simplifying spaceflight without as many Rube Goldberg space assembly missions by using larger LVs


newtype_alpha wrote: View Post
Which ignores the fact that the United States does not need the mission capability provided by the F-35
We agree on that at least.

************************************************** **************


gturner wrote: View Post

Um, that's idiocy nested several levels deep...
That wasn't the arguement I was making mind you, that was the letter writers.' From what I understand Falcon can fly depressed trajectory in addition to having engine out capability, so it is number one in my book. My concern is that a lot of negativity that Ares/ Constellation faced (and that SLS faces now) will be turned against Musk. You have to know where the arguement is coming from. But this is how it starts. I recognized the letter writers name because--if you keep up with the trades, you see a lot of the same names: Sietzen, Lyles (Lester and Doug) Sega, etc. I'm worried that Musk may be facing more hit pieces in the near future.

gturner wrote: View Post
The RD-180 uses a mixture ratio of 2.7:1, but it makes the pre-burner difficult to make because it has to run in a high temperature oxidizing environment.
And if there is one thing you want to avoid, its hot oxygen. From what I understand, RD-180 is the two nozzle half-strength version of the Zenit first stage/Energiya strap-on's RD-170 series engine of Glushko. He liked hypergolics but wanted time to perfect kerolox designs and Korolev [sic] pushed him, leading to the falling out--among other things (Kolyma).

Now from what I understand, the hydrogen engine equivalent to SSME was the RD-0120, which never had the burn through trouble that Glushko had with the RD-17X series, yet he didn't like the idea of the Energiya having hydrogen.

To me, that is not a problem in that hydrogen's trouble of having low density and high volume just leads to a wider HLLV shroud and all the advantage that comes with that.

Delta IV to me is the worst rocket. It is unwieldy compared to Atlas or even Falcon, yet not really big enough to use hydrogen effectively as opposed to an Energiya/ET/SLS/Ares V type design.

On the subject of Falcon's recent anomaly:
http://www.youtube.com/watch?feature...&v=y6zsZiVa998

I'm a big believer in engine-out capability--and this proves that a failure in a densely packed aft section need not lead to fratricide. Now I understand that Musk wants to move the engines out around the outer 'rim' of the rocket. I wonder if that might actually make things worse.

When you have engines close together, I would think you would have a venturi effect where any debris would get entrained into the engine exhaust and be hurled downward and away.


I wonder if you widen the area between engines--that you might introduce a stagnant zone that might allow debris to have a more sideways ejection. Any thoughts about that?

Last edited by publiusr; October 12 2012 at 10:52 PM.
publiusr is offline   Reply With Quote
Old October 12 2012, 11:38 PM   #223
sojourner
Vice Admiral
 
sojourner's Avatar
 
Location: I'm at WKRP
Re: Envisioning the world of 2100

Musk is not "moving the engines out to the rim". SpaceX is changing the arrangement from 3x3 to an octagonal arrangement with one in the middle. The new arrangement provides a little more range of movement for the central engine to gimbal while also utilizing a more efficient thrust structure and eliminating the need for the 4 outer fairings.

Technically, they are pulling the 4 outer engines in.
__________________
Baby, you and me were never meant to be, just maybe think of me once in a while...
sojourner is online now   Reply With Quote
Old October 13 2012, 12:29 AM   #224
gturner
Admiral
 
Location: Kentucky
Re: Envisioning the world of 2100

publiusr wrote: View Post
gturner wrote: View Post

Um, that's idiocy nested several levels deep...
That wasn't the arguement I was making mind you, that was the letter writers.' From what I understand Falcon can fly depressed trajectory in addition to having engine out capability, so it is number one in my book. My concern is that a lot of negativity that Ares/ Constellation faced (and that SLS faces now) will be turned against Musk.
It won't matter to him. In "The Avengers" we saw how much Iron Man cared for the opinions and objectives of SHIELD, and as even Robert Downey Jr. admitted, Elon Musk is Tony Stark.

gturner wrote: View Post
The RD-180 uses a mixture ratio of 2.7:1, but it makes the pre-burner difficult to make because it has to run in a high temperature oxidizing environment.
And if there is one thing you want to avoid, its hot oxygen. From what I understand, RD-180 is the two nozzle half-strength version of the Zenit first stage/Energiya strap-on's RD-170 series engine of Glushko. He liked hypergolics but wanted time to perfect kerolox designs and Korolev [sic] pushed him, leading to the falling out--among other things (Kolyma).
Yes, the RD-180 is a half-RD-170. Interestingly, the RD-170's higher specific impulse compared to the F-1 means a Saturn V with 4 RD-170's would outperform one with five F-1's.

To me, that is not a problem in that hydrogen's trouble of having low density and high volume just leads to a wider HLLV shroud and all the advantage that comes with that.
If we had a high power RP-1 engine (like the RD-170 or Musk's 1.8m lbs proposal), they could use the SLS first stage as a second stage, ala Saturn V on steroid. The configuration they have now is a Shuttle-derived version of North American's Saturn II INT-17 proposal, which strapped Titan SRB's to the Saturn S-II stage, with an S-IVB on top, to give them a payload capability in between the Saturn IB and Saturn V.

I'm a big believer in engine-out capability--and this proves that a failure in a densely packed aft section need not lead to fratricide. Now I understand that Musk wants to move the engines out around the outer 'rim' of the rocket. I wonder if that might actually make things worse.
It should improve the mass ratio because the force will be more in line with the load-bearing skin, and it should also increase stability at the expense of slightly more base drag.

I'm not sure the seperation would have much affect on debris, but you shouldn't have birds nesting in there anyway.
gturner is offline   Reply With Quote
Old October 13 2012, 03:38 AM   #225
Crazy Eddie
Rear Admiral
 
Crazy Eddie's Avatar
 
Location: I'm in your ___, ___ing your ___
Re: Envisioning the world of 2100

publiusr wrote: View Post
The shuttle derived crowd has always been on the outside looking in--wanting something tried and true. Venture Star should have suffered the ire aimed now at SLS which is far simpler.
Except that, unlike the SLS, Venture Star was actually a pretty good idea. The only complicated part of the venture star was the composite propellant tanks that NASA couldn't get to hold integrity under full propellant loading.

That, ironically, is what Venture Star and SLS have in common: both include features that were inserted for political reasons, and otherwise aren't in any way necessary for the system's development.

NASA shouldn't be run by businessmen--that was my point all along--or they would have bailed on Webb.
You say that like it's a bad thing.

It isn't about profit man
If we ever plan to get serious about expanding humanity's reach into space, it needs to be. We need to sort of grow up and admit to ourselves that the real world isn't like Star Trek, and the people who are going to make the biggest breakthroughs colonizing the final frontier aren't going to do it for free. SOMEBODY has to pay for it. It does not have to be taxpayers (not exclusively, and eventually not at all).

HLV proponents are the ones capable of looking at the history of spaceflight
The ENTIRE history of spaceflight includes less than a dozen flights by HLVs of any kind. One of those HLV flights deployed a space station whose life was cut tragically short by the lack of a mature spaceflight infrastructure in its country of origin.

That history ALSO includes eight space stations whose modules, crews and supplies were launched by much smaller vehicles. It also includes two whose modules were deployed by smaller rockets and were assembled in orbit with the help of orbiting vehicles. It includes four successfully developed cargo vehicles designed to launch on medium-lift rockets, and a fifth soon to fly in the near future. It includes the Mercury and Gemini programs, and more than forty years of consistent service by the Soyuz, and it includes the Shenzhou program and the in-development Tiangong modules.

HLVs have proven useful in one and only one application: the ability to launch an extremely small expedition to the surface of the moon with a very short development schedule. In other words, an HLV is exactly the kind of rocket you need if you want to beat your political rival in a space race.

So do we need to beat China to a near earth asteroid? Is that what's going on here?

So I'm supposed to think your word is worth more than theirs?
I couldn't care less who YOU believe. There is a lot of interesting work being done right now on spaceflight architecture and launch systems that will, over time, evolve into the kind of infrastructure we will need to really expand into space. HLVs will not be part of that infrastructure, and if NASA is forced to spend the entire bank on the SLS, they won't be part of it either.

Nelsons district will get space money no matter what rocket is used.
But not nearly as much, and not a guaranteed supply if private contractors are competing for reduced costs and increased capability.

I think a lot of Griffins priorities of simplifying spaceflight without as many Rube Goldberg space assembly missions by using larger LVs
Which is idiotic, because both NASA and the Russians have been using the "rube goldberg" technical for forty years and it has worked every single time; it has been proven to be cheaper, easier, more efficient and less dangerous. The singular disadvantage is that is SLOWER, which is only a disadvantage if you're in a hurry. And while the Mike Griffins of the world are happily "simplifying" spaceflight by forcing larger vehicles into production, who's going to be carrying crews and supplies to space stations in Earth Orbit? Who's going to be servicing the Hubble or its successors? Who's going to reboost the ISS or its successors when its orbit begins to decay? Who's going to send parts and equipment to repair those stations/satellites/telescopes when something unexpected happens to them?

All I know is, there is an American space craft in orbit right now, and it wasn't launched on an HLV.

SPEAKING of the history of spaceflight, HLVs have a considerably lower success rate, especially in light of the Polyus fiasco and the near-failure of Skylab.

Speaking more of the history of spceflight, I was recently reminded that the original Atlas rockets -- the very systems from which the current expendable launch vehicles evolved -- were instrumental in the Mercury program. Strictly speaking, EELVs have a more important place in that history than HLVs ever will.
__________________
The Complete Illustrated Guide to Starfleet - Online Now!
Crazy Eddie is offline   Reply With Quote
Reply

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT +1. The time now is 03:56 PM.

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
FireFox 2+ or Internet Explorer 7+ highly recommended.