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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-01 03:46pm
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To be fair to HMS, the US maintains a rocket industry and makes satellite launch vehicles. If we really wanted to replace the Saturn V, we could probably do it now in roughly the same amount of time it took us to do it in the 1960s, and we'd probably get a better rocket out of the program.

What I was getting at isn't so much the lack of resources, either physical resources or human resources. We have those in the US. What is missing is the intangibles. The US today suffers from feckless, bickering leadership, a strong tendency by both the political class and much of the electorate to be penny-wise and pound-foolish, and a lack of commitment on the part of the ruling class to build things, to create permanent, long-lasting achievements.

We saw what happened when Bush decided he wanted a Saturn V equivalent rocket: it toodled along for a few years, and just as it was gathering momentum, Obama canceled it in the wake of a recession that was brought about in large part by the financialized, Wall Street-dominated model of capitalism that's taken control of the US in the past quarter century at the expense of the older model.

A person, or a country, that has the physical strength but not the willpower to accomplish something isn't necessarily "able" to do it- or at least, I doubt Stas would say that he is able.

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-01 04:17pm
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Yeah, I know it does not apply to the US, which still has the relevant industrial base. However, his argument (GDP big = WIN) was simply too stupid not to shoot some holes in. If we really wanted, we could have spaceships running to Pluto and back in seven months or so (I read about that in a study). Fact is, we don't.

HMS argument about aircraft carriers is, in fact, a nice illustration of the point. We're not making dozens spaceships to take us to Pluto. But we're making dozens of 100 000 ton ship monstrosities to murder each other in a technologically advanced fashion. The US doesn't want to put a permanent base on the Moon, but it keeps a dozen aircraft carriers operational.

"Technological sophistication" is not all there is; there's also the matter of goals and priorities, as you said. If your priorities have created a certain type of construction, e.g. naval construction has priority over the exploration of space, then the result is going to be lackluster even if you're having the best space tech people.



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-02 04:22am
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Stas Bush wrote:
I understand the danger (hell, it forms a major plot point :lol: ). I'm just curious as to the numbers. You can't beat nuclear pulse with liquid or solid fuels, so what sort of a propulsion system will the "space train" use? Any calculations? I couldn't find this shit in "Atomic Rockets", sadly, since they're focusing too much on Grand Sci-Fi and not just Solar system colonization.
You read my whole post right? I thought I said what was the proposal.

The only way to fuck rocketry (i.e. making a craft with a decent performance that isn't burning immortal souls) is not carrying your own fuel.

now as for calcs, that's relatively easy. It's stuff coming at you at speed X and crashing on your pusher plate, so the Ve of the engine is the speed of the impactors. Given that hard-ish Orion's Ve is kinda crappy at 40-ish km/s, this should have similar performance in routes served by the impactor swarms. You just need to book the flight a year or so in advance so that the impactors have time to be diverted from the parking orbit and come at you.

say we want to give 50 km/s of delta-v to a craft weighting 1000 tons, using impactors coming at 50 km/s,:

F= TotalMass * acceleration
F= mDot*Ve

so (TotalMass * acceleration)/Ve=mDot

Given that here I just want a general overview, I'll assume an instantaneous 10 km/s acceleration, so that the mDot (mass flow) will tell me how much mass of impactors I need.
In reality you would of course spread that mass over a bit longer time to avoid nuking the craft.

(1'000'000 kg* 50'000 m/ss)/50'000 m/s = 1'000'000 kg

So, with 1000 tons worth of cheap mass-produced impactors at 50 km/s you gave 50 km/s of delta-V to a craft weighting 1000 tons.

A comparable Orion-ish drive would require a slightly smaller mass of tiny nukes.



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-02 10:40am
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Stas Bush wrote:
HMS Conqueror wrote:
Even if your economy is currently geared to produce bras and movies, it means you have enough money to retool if you want to.

Retooling isn't a question of money. If you have zero nuclear engineers, you can't build a nuclear reactor; someone will have to do it for you. Humans are the most valuable commodity which cannot be "retooled" at your whim. It takes more than 20 years to create a skilled spacecraft engineer capable of solving necessary tasks. You need hundreds of them and dozens of very smart guys, and probably a pair of real visionaries, to complete a revolutionary spacecraft.

A human retooling factory is called a university. There is also a steady supply of newly produced humans who can be tooled as required.

The total age of NASA prior to the first Saturn V being built is less than 20 years, and that is when Saturn V was actually something new and difficult. Most of the hard work is done already.

Quote:
HMS Conqueror wrote:
An aircraft carrier is much larger and more complex than a rocket.

The engineering challenges are very different. One is a weapon; the other a tool of exploration. One is a ship which goes through water, and the likes of which have been built since the early XX century. Another is a craft which moves through air and vacuum with rocket propulsion. You just can't take a shipbuilder and "reassign" him to build rockets, the world isn't a fucking Civilization game.

Ford is more advanced than Saturn V, requiring more scientific knowledge and skill. Most of this is in designing the radars. In the same sense that we have been building ships for hundreds of years, rockets were used at the Battle of Leipzig and by Indian Sultans in the 18th century. It's just bigger, right?

Quote:
HMS Conqueror wrote:
In fact rockets and other 1950s tech have fallen so far down the ladder that they're being built by aforementioned third world countries.

This is because we're speaking about simple, non-revolutionary designs, the principles for which are widely disseminated and knowledge is spreading to the more ambitious Third World nations.

Could a Third World nation go and complete a project like Space Shuttle or Energia in, say, 5 years? No. Because the knowledge's just not there, the necessary humans are just not there and maybe, worse yet, the necessary materials aren't there either (Chinese metallurgy reaching the "make spacecraft" level only at the break of the century is a prime example).

It is stupid to pretend that you could "reassign" people to make A not B in an instant

Their designs are equally as complex as the US designs, which is not terribly, at least by current standards. "It's not rocket science" is just a phrase; rocket science isn't rocket science. The Soviets already rushed out a knock-off shuttle just in time to collapse in 1990; no one else will do it now because history has shown the shuttle was basically a bad idea, but that's a different issue. If we wanted to go to Mars or blast a man around Pluto or whatever to show that society hasnt regressed in his ability to conduct pointless vanity projects, it would use conventional rockets to get off earth.

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-02 11:55am
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HMS Conqueror wrote:
The total age of NASA prior to the first Saturn V being built is less than 20 years

Wow, talk about dishonesty. People working for military rocketry projects and already studying rocket science in universities in aerospace programs back before NASA was created doesn't count? You're really dumb.
HMS Conqueror wrote:
pointless vanity projects

Sure, because humanity's OOC problem survivability while staying on Earth is so grand. I mean, it's not as if the entirety of mankind could be thrown back to feudalism by a mere asteroid impact strong enough to cause a protracted global cooling, no sir.
HMS Conqueror wrote:
Their designs are equally as complex as the US designs

And these Third World nations are probably China and India, both of which have have a reasonably massive bulk industrial production base (absolutely huge in case of China) and long-running space programs? Maybe you could include Brazil, yup.
HMS Conqueror wrote:
A human retooling factory is called a university. There is also a steady supply of newly produced humans who can be tooled as required.

If your universities put out zero nuclear scientists, you can't just go from zero to "thousands" in a matter of one year. It also probably signifies deeper problems about your country, but in any case, it takes decades to build up a base of specialists in hard sciences, engineering et cetera. The USSR didn't jump into space without preparing dozens of thousands of engineers in the 1930s, 40s and 50s. Neither did the USA.

You're just being dishonest, aren't you?

Hey, let's talk about how money can do anything in the blink of an eye. Can Qatar (with a thrice higher GDP per capita than Taiwan) put out several dozen million units of high-quality electronics next year? If no, why?



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-02 12:07pm
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Stas Bush wrote:
HMS Conqueror wrote:
The total age of NASA prior to the first Saturn V being built is less than 20 years

Wow, talk about dishonesty. People working for military rocketry projects and already studying rocket science in universities in aerospace programs back before NASA was created doesn't count? You're really dumb.

By the same token it should take thousands of years to redevelop any lost technology, but in reality it doesn't take the total development time of all world shipbuilding history up to 400BC in order to build a trireme (this has been done).

Nb: rocketry is not even a lost industry. US has had continuous rocket production since before foundation of NASA. Pre-NASA scale rocketry research is below the level of routine industrial production of eg. military missiles and rockets, now regarded as just disposable ammunition.

Quote:
HMS Conqueror wrote:
pointless vanity projects

Sure, because humanity's OOC problem survivability while staying on Earth is so grand. I mean, it's not as if the entirety of mankind could be thrown back to feudalism by a mere asteroid impact strong enough to cause a protracted global cooling, no sir.

No I don't think so.

But consider the implications fully: value of this has to be weighted against the cost of creating a self-sustaining off-world colony (something that is, I think, well beyond our current economic capacity, unlike moon/mars/pluto landing or hurling a man into the interstellar medium) and the probability of a cataclysmic natural disaster (very low).

Quote:
HMS Conqueror wrote:
Their designs are equally as complex as the US designs

And these Third World nations are probably China and India, both of which have have a reasonably massive bulk industrial production base (absolutely huge in case of China) and long-running space programs? Maybe you could include Brazil, yup.

They just have large populations, giving large GDP despite generally low levels of technology and economic development. This allows them to fund small groups of high tech workers and facilities. Something you seem to think is not possible...

Quote:
HMS Conqueror wrote:
A human retooling factory is called a university. There is also a steady supply of newly produced humans who can be tooled as required.

If your universities put out zero nuclear scientists, you can't just go from zero to "thousands" in a matter of one year. It also probably signifies deeper problems about your country, but in any case, it takes decades to build up a base of specialists in hard sciences, engineering et cetera. The USSR didn't jump into space without preparing dozens of thousands of engineers in the 1930s, 40s and 50s. Neither did the USA.

You're just being dishonest, aren't you?

There were thousands of 'nuclear scientists' just among people who were at university before 'nuclear science' was a field. I am not sure it would take more than one year to train a lot of rocket scientists if you really wanted to (take people who already have physics/engineering degrees; 1 year is about the length of a masters'), but 1 year is way under the development time of a big new industrial project anyway.

Now if you want to discuss how long it would take to rebuild US tech capacity if everyone with a hard science education was suddenly killed, that might be interesting, and it could possibly take longer than the historical Saturn programme (though I am not sure of this), but it would be way off the actual situation.

Quote:
Hey, let's talk about how money can do anything in the blink of an eye. Can Qatar (with a thrice higher GDP per capita than Taiwan) put out several dozen million units of high-quality electronics next year? If no, why?

Sure, it can buy a fab plant from Taiwan, disassemble it and re-assemble it in Qatar. What's with the one year thing, though? Saturn program took about a decade.

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-02 02:19pm
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HMS Conqueror wrote:
By the same token it should take thousands of years to redevelop any lost technology, but in reality it doesn't take the total development time of all world shipbuilding history up to 400BC in order to build a trireme (this has been done).

Because for a technology to become lost, it has to be a primitive technology. Primitive technologies imply an ease of copying, since they do not require sophisticated concepts that we know now.
HMS Conqueror wrote:
Nb: rocketry is not even a lost industry. US has had continuous rocket production since before foundation of NASA. Pre-NASA scale rocketry research is below the level of routine industrial production of eg. military missiles and rockets, now regarded as just disposable ammunition.

Rocketry being 'lost' has never been my point. Strawman.
HMS Conqueror wrote:
No I don't think so.

You do, since you seem to think that having the minute comfort of the Earth is more valuable than eliminating existential risks to long-term survivability one by one.
HMS Conqueror wrote:
But consider the implications fully: value of this has to be weighted against the cost of creating a self-sustaining off-world colony (something that is, I think, well beyond our current economic capacity, unlike moon/mars/pluto landing or hurling a man into the interstellar medium) and the probability of a cataclysmic natural disaster (very low).

Mars space elevator: feasible with current materials. LEO rockets with extreme capacity: feasible with 1960s materials. Caves of Mars gives us a few nice examples of where you could put a self-sustained colony underground. Yes, population control techniques will have to be rather advanced, but if you start with an enclosed self-sustained biosphere underground, you should be able to work from there.
HMS Conqueror wrote:
They just have large populations, giving large GDP despite generally low levels of technology and economic development. This allows them to fund small groups of high tech workers and facilities. Something you seem to think is not possible...

Nay, they have long-term space programs and their industry, especially in case of China, is reasonably well-developed.
HMS Conqueror wrote:
There were thousands of 'nuclear scientists' just among people who were at university before 'nuclear science' was a field.

There were many physics specialists, but few nuclear scientists. The entire history of the Manhattan project demonstrated that you need dozens of leading scientists and thousands of ordinary executors, e.g. construction workers, to do something like that. While the workers do not pose a problem once they reach a certain level of knowledge, the scientists certainly do. The pathetic flop of the Axis in the creation of nuclear weapons proves it once again. Leading scientists left the Axis for the USA due to racist policies, which left them bereft of specialists of a high enough class to actually complete the project.
HMS Conqueror wrote:
I am not sure it would take more than one year to train a lot of rocket scientists if you really wanted to (take people who already have physics/engineering degrees; 1 year is about the length of a masters'), but 1 year is way under the development time of a big new industrial project anyway.

Nowadays with the compression of education you could technically take people with a physics degree (which itself takes years to get) and educate them in rocket science, except if those are your only assets, they are going to be inexperienced. If there is no leading cadre and those are the first rocket scientists you have, your projects will have to experience a string of flops until you get a core cadre of people who are experienced with rocket construction and went through several programs already. Those will then train your freshmen and lead projects. So from zero to hero there's a lot of (a) education (b) practice.
HMS Conqueror wrote:
Now if you want to discuss how long it would take to rebuild US tech capacity if everyone with a hard science education was suddenly killed, that might be interesting, and it could possibly take longer than the historical Saturn programme (though I am not sure of this), but it would be way off the actual situation.

I'm simply saying that the effects of degradation in a given field (be it the number of hard science degrees, experience or leading minds) are non-linear and their exact consequences cannot be predicted. The Axis lost Einstein and Fermi and a couple of other guys, but the consequences were quite severe, if not directly understood at the time.
HMS Conqueror wrote:
Sure, it can buy a fab plant from Taiwan, disassemble it and re-assemble it in Qatar. What's with the one year thing, though? Saturn program took about a decade.

"Buy a fab plant in Taiwan"? So why hasn't it done so already? Everyone knows that oil is finite and advanced technology is a good product to sell, right? *laughs* Besides, it will have to buy the fab plant with a set of Chinese slaves, or import workforce.

Which once again brings me to the initial point: from zero to hero takes time, else you'd be forced to buy things from someone.

Buying a plant is a cop out. You don't have a full tech chain to recreate it. What if machine tools wear out? The Qataris won't be able to rebuild them, since they lack a machine tool industry.

Which once again demonstrates that by ignoring the tech chain you end up with a stupid statement "BUT THEY CAN ALWAYS BUY A PART OF THE CHAIN!", well sure they can, Captain Obvious. They can also buy the end product. Why launch rockets at all if you can buy them, e.g. from Russia for example? Right? ;) They can buy the plant but they'll still be dependent on Taiwan for everything else. Not just raw materials, but the maintenance and refurbishment of the plant as well. This is not them doing it, that's the Taiwanese doing it for them.

Likewise, you can put a factory assembly line for cars and import all components from elsewhere. That's not you making cars. That's you assembling cars. You don't have the entire chain of production? You're not able to do it on your own, end of story.



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-02 07:52pm
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PeZook wrote:
Skgoa wrote:
Funny how you moved the goalposts from "there was no soviet moon program in 1968" to "the soviet moon program in the early 70ies wasn't a REAL program because they didn't spend as much money on it as the US did." :lol: Also, congrats on working in how much better 'Murricans are. But really, what I find most astonishing is that the cognitive dissonance, that you get from stating both that there was no development program AND that this development had many failures AT THE SAME TIME, just has to hurt.


Funny how Simon never said "there was no soviet moon program",and in fact claimed this from the start:

Simon_Jester wrote:
1) The Soviets had designs for 'moon shot' hardware, but none of it was ever close to a manned flight. They might have gambled on a Zond flight in 1968-70, but based on the performance of the unmanned Zond capsule tests, it would have been hellaciously risky. To actually put a man on the moon, as opposed to just circling around it and coming back a la Zond, they would have had to build and develop a lot of stuff that historically, they never got the budget for. It's not that the Soviets couldn't have gone to the Moon, it's that the Soviet government never committed the huge scale of funds and resources it would take to make it happen, so most of the hardware never got beyond the prototype/blueprints phase and the missions were never planned beyond the 'rough sketch' level.


Simon merely said the Soviets had little hope of landing on the Moon before Americans, not that they didn't have a moon program at all. NOBODY ELSE said there was no Soviet moon program, either. I contested your claim that the Soviets could've landed before Americans did if Apollo 11 failed, because in 1969 their program was incredibly, hopelessly behind and lacking several pieces of critical hardware - and thus could only have succeeded in beating the US if the Americans abandoned Apollo entirely.

And, as I keep pointing out, that's still all besides the point. The point still being that I said there was a soviet moon program. (Go check, it's on the first page I believe.) Every post made in answer to that is a) about there being a soviet moon program or b) besides the point.
Also, as a minor nitpick: that quote is factually wrong but that's still beside the point.

And indeed, those three point are what I have been reiterating: there was a soviet moon program, talking about however differently you think it should have been done is besides the point and Simon has written a couple of things that reality disagrees with. How many more times do we need to go over this?



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-02 08:12pm
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ghetto edit:

Actually, I was wrong. This is what started it:
Simon_Jester wrote:
Seriously, while the Russians had plans for lunar missions, there was never a serious, systemic effort by the USSR to put a man on, or even near, the moon.

This is, as I have pointed out again and again, wrong. I don't fucking care how likely anyone feels it would have been for the soviets to win the space race. (Pretty unlikely IMHO.) But they tried their best and got beaten fair and square. This is important when viewin that sentence in context, because that post was a claim that the US would not have gone to the moon if the moon landing had not been the one driving factor. But in reality the soviets, who hadn't collectively been challenged by Kennedy to achieve this within a decade, were still on the path to a moon landing within two decades at most. (And they only really got into their heads that Kennedy had meant what he said a few years before Apollo 11. WHo knows what could have happened if they had seen this as a race as soon as the early 60ies.)



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This is pre-WWII. You can sort of tell from the sketch style, from thee way it refers to Japan (Japan in the 1950s was still rebuilding from WWII), the spelling of Tokyo, lots of details. Nothing obvious... except that the upper right hand corner of the page reads "November 1931." --- Simon_Jester

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-03 07:17am
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someone_else wrote:
Stas Bush wrote:
I understand the danger (hell, it forms a major plot point :lol: ). I'm just curious as to the numbers. You can't beat nuclear pulse with liquid or solid fuels, so what sort of a propulsion system will the "space train" use? Any calculations? I couldn't find this shit in "Atomic Rockets", sadly, since they're focusing too much on Grand Sci-Fi and not just Solar system colonization.
You read my whole post right? I thought I said what was the proposal.

The only way to fuck rocketry (i.e. making a craft with a decent performance that isn't burning immortal souls) is not carrying your own fuel.

now as for calcs, that's relatively easy. It's stuff coming at you at speed X and crashing on your pusher plate, so the Ve of the engine is the speed of the impactors. Given that hard-ish Orion's Ve is kinda crappy at 40-ish km/s, this should have similar performance in routes served by the impactor swarms. You just need to book the flight a year or so in advance so that the impactors have time to be diverted from the parking orbit and come at you.

say we want to give 50 km/s of delta-v to a craft weighting 1000 tons, using impactors coming at 50 km/s,:

F= TotalMass * acceleration
F= mDot*Ve

so (TotalMass * acceleration)/Ve=mDot

Given that here I just want a general overview, I'll assume an instantaneous 10 km/s acceleration, so that the mDot (mass flow) will tell me how much mass of impactors I need.
In reality you would of course spread that mass over a bit longer time to avoid nuking the craft.

(1'000'000 kg* 50'000 m/ss)/50'000 m/s = 1'000'000 kg

So, with 1000 tons worth of cheap mass-produced impactors at 50 km/s you gave 50 km/s of delta-V to a craft weighting 1000 tons.

A comparable Orion-ish drive would require a slightly smaller mass of tiny nukes.

So this is a system which does not allow any unpredictable maneuvers on part of the ship, even if they are absolutely needed. Thank you, I'll stay with my Orion, at least for passenger flights.



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-03 10:07am
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Stas, Orion would not work. I neither know nor care if these points have been braught up but:
- You would need magical nukes that never materialized.
- The pusher plate would have to be made out of unobtainum or be so massive that it's just not worth it.
- It's a political impossibility to allow someone to throw nukes out the back of their space ship.
- You can't even use it for anything but ultra-long-distance flights, because you simply can't detonate nukes near your other space infrastructure.

So yeah, use it in a story if you like... but Orion has no place in a thread about realistic proposals.



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This is pre-WWII. You can sort of tell from the sketch style, from thee way it refers to Japan (Japan in the 1950s was still rebuilding from WWII), the spelling of Tokyo, lots of details. Nothing obvious... except that the upper right hand corner of the page reads "November 1931." --- Simon_Jester

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-03 10:24am
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Simon_Jester wrote:
We saw what happened when Bush decided he wanted a Saturn V equivalent rocket: it toodled along for a few years, and just as it was gathering momentum, Obama canceled it in the wake of a recession [...]

To be fair to Obama, Bush's grand vision for space only existed in his speeches and never got the funding it would have needed. Doesn't make the rest of your post any less true but I just wanted to point out that Constellation was doomed form the word go. I would even go so far to say that the decissions Bush the Lesser took in his first term were what brought on NASA's current crisis. But then again, I could also trace it all back to Nixon who axed most of NASA's plans and only gave them funding for the Shuttle... but not the missions the Shuttle was supposed to fly. :D



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This is pre-WWII. You can sort of tell from the sketch style, from thee way it refers to Japan (Japan in the 1950s was still rebuilding from WWII), the spelling of Tokyo, lots of details. Nothing obvious... except that the upper right hand corner of the page reads "November 1931." --- Simon_Jester

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-03 10:34am
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People keep pointing out NASA's budget is just as high in real terms as it was in the good ol' glory days of Apollo, but while this is somewhat true, they keep forgetting that NASA today has piles of obligations and highly important projects that it has to pay for, too.

It's like politicians keep expecting NASA to do more with less, in order to get some supeficial cuts to the budget while approving gigantic projects that dwarf the proposed savings literally by orders of magnitude.



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-03 01:14pm
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Skgoa wrote:
Stas, Orion would not work. I neither know nor care if these points have been braught up but:
- You would need magical nukes that never materialized.


?

Quote:
- The pusher plate would have to be made out of unobtainum or be so massive that it's just not worth it.


Source? I've heard otherwise, so I'm curious about this.

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-03 01:47pm
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Pendleton wrote:
Skgoa wrote:
Stas, Orion would not work. I neither know nor care if these points have been braught up but:
- You would need magical nukes that never materialized.


?

The original proposal featured nukes that they thought were just around the corner but that were never achieved. This means Orion would be less effective in reality than they calculated.


Pendleton wrote:
Quote:
- The pusher plate would have to be made out of unobtainum or be so massive that it's just not worth it.


Source? I've heard otherwise, so I'm curious about this.

I would have to look the source up but basicly the shockwave going through the pusher plate could make its material "flake off" and shred the spacecraft.



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-03 02:30pm
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Skgoa wrote:
To be fair to Obama, Bush's grand vision for space only existed in his speeches and never got the funding it would have needed. Doesn't make the rest of your post any less true but I just wanted to point out that Constellation was doomed form the word go. I would even go so far to say that the decissions Bush the Lesser took in his first term were what brought on NASA's current crisis.
Considerable sums of money were spent on Constellation regardless- the money certainly existed to fund it, and had Obama decided to double down we would probably still be working away at it and making considerable progress.

What it comes down to is that if you define "over budget and takes longer than expected" as "doomed," virtually every major project in the history of mankind was 'doomed' at some stage of development. Getting impressive results in a hurry on a shoestring budget isn't something you can demand of engineers on a regular basis.

You get the worst of both worlds by spending money on programs for years at a time, then canceling them and starting over every time it looks like they won't make the optimistic initial budget and schedule projections. Canceling something and starting over from scratch will never, ever get you the result you wanted faster, and it will rarely if ever get you the result cheaper.

Skgoa wrote:
The original proposal featured nukes that they thought were just around the corner but that were never achieved. This means Orion would be less effective in reality than they calculated.
This does not, in and of itself, make the idea a pipe dream.

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 04:32am
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Skgoa wrote:
Stas, Orion would not work. I neither know nor care if these points have been braught up but:
- You would need magical nukes that never materialized.
- The pusher plate would have to be made out of unobtainum or be so massive that it's just not worth it.
- It's a political impossibility to allow someone to throw nukes out the back of their space ship.
- You can't even use it for anything but ultra-long-distance flights, because you simply can't detonate nukes near your other space infrastructure.

So yeah, use it in a story if you like... but Orion has no place in a thread about realistic proposals.

All of it simply not true or irrelevant under my scenario.

1) Nuclear shaped charges were feasible with 1960s technology and they're even more feasible now. Their non-occurence is a matter of little necessity, not theoretical or practical impossibility.
2) Ablation could be dealt with back in the 1970s, and certainly could be dealt with now
3) Only in a world where you have bickering nations with massive militaries fighting for dominance over the Earth
4) Yep, only orbit-to-orbit transit, which is the question for an advanced system-colonizing civilization, not the "transit between Earth and LEO".



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 08:26am
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Stas Bush wrote:
So this is a system which does not allow any unpredictable maneuvers on part of the ship, even if they are absolutely needed. Thank you, I'll stay with my Orion, at least for passenger flights.
Depends from what you mean by "unpredictable maneuvers". The craft will likely have some kind of rocket propulsion for maneuvering and move about when in orbit around planets and do some minor course corrections like modern probes do nowadays, but if you mean "dramatic course change", then I'll have to disappoint you saying that even an Orion if it is a truly commercial vessel (i.e. hopes to turn a profit) is not going to carry enough fuel to do it when it means doubling or even tripling wasted mass (also the cost, that fuel being nukes).

Besides, as Skgoa points out, your Orion vessels will have to employ rockets as well when "close" to anything else they want to dock with (or use plenty of shuttles, which is slightly smarter, albeit much less cool), so the difference will be not be so marked.

For that matter, NERVA-like engines have the same issue.

Skgoa wrote:
- You would need magical nukes that never materialized.
- The pusher plate would have to be made out of unobtainum or be so massive that it's just not worth it.
I believe that this was for the fusion nuke orions, or the interstellar craft proposals where they went totally nuts and started throwing numbers without any logic.
The fission ones were relatively crappy in comparison but were good enough to do what Stas needs, performance-wise.

The cost is very likely to make them completely uneconomic, imho. wikipedia says that estimates were around 300'000 modern dollars per bomb, and all designs needed something like 800 bombs just to reach orbit. 240 million dollars only for the fuel to fucking reach orbit.
And before you start bitching, reaching orbit is easier since:
-you use atmosphere as propellant
-the delta-v needed to get anywhere in a speed worth using Boom-Boom-Orion is 3-4 times that of reaching orbit.

So, what the hell is worth a billion or more in shipping costs?



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 08:38am
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Uh...what sort of payload are we talking about? Because right now it costs a billion bucks to ship 100 tonnes of stuff into LEO ; If you can ship 1000 tonnes to MARS for a similar amount of money, then that's a really major win, costwise.

Of course, I have to wonder about our fissile reserves if we decided to use Orions to set up a Mars colony :D



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 08:44am
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someone_else wrote:
Depends from what you mean by "unpredictable maneuvers". The craft will likely have some kind of rocket propulsion for maneuvering and move about when in orbit around planets and do some minor course corrections like modern probes do nowadays, but if you mean "dramatic course change", then I'll have to disappoint you saying that even an Orion if it is a truly commercial vessel (i.e. hopes to turn a profit) is not going to carry enough fuel to do it when it means doubling or even tripling wasted mass (also the cost, that fuel being nukes).

Orions in my view are not a commercial vessel; they are an exploration vessel and a passenger system ferry, used to cover huge distances quickly (e.g. to Mars orbit in weeks instead of many months). This is critical to avoid massive problems with moving human personnel to and from faraway worlds. Commercial vessels are cargo vessels, and those can be operated on whatever principles one likes.
someone_else wrote:
Besides, as Skgoa points out, your Orion vessels will have to employ rockets as well when "close" to anything else they want to dock with (or use plenty of shuttles, which is slightly smarter, albeit much less cool), so the difference will be not be so marked.

They wouldn't have to deal with atmospheric friction and if we employ space elevators on Mars and Moon (feasible with current materials) and possibly a skyhook thing on Venus (not sure about that), they could use either shuttles or something like that for low-orbit docking. Which is quite cool in my view; a huge ship that never leaves high orbits and smaller ships which bring passengers to/from the main transport is quite efficient.
someone_else wrote:
I believe that this was for the fusion nuke orions, or the interstellar craft proposals where they went totally nuts and started throwing numbers without any logic. The fission ones were relatively crappy in comparison but were good enough to do what Stas needs, performance-wise.

Yeah, that was with the Daedalus ICF project.
someone_else wrote:
The cost is very likely to make them completely uneconomic, imho. wikipedia says that estimates were around 300'000 modern dollars per bomb, and all designs needed something like 800 bombs just to reach orbit. 240 million dollars only for the fuel to fucking reach orbit.

They should be assembled in space, ideally, not to worry about aerodynamics and wasting bombs to raise them up. How many bombs would the ship need to get from Earth orbit to Mars orbit?
someone_else wrote:
So, what the hell is worth a billion or more in shipping costs?

Intersystem passenger traffic, of course. Humans don't want to wait for freaking years in transit to the moons of Jupiter. Besides, if you can build an SSTO, that means you can raise enough material and fuel into orbit to make the question of "leaving atmosphere with nukes" moot.

Orions are quite dangerous since high-altitude nuclear exposions also pose wide-area EMP risks, one shouldn't be operating them in the atmosphere.
PeZook wrote:
Of course, I have to wonder about our fissile reserves if we decided to use Orions to set up a Mars colony

Wouldn't combined fission-fusion charges work for NPP, though? This should ease the strain on the uranium.

Also, Earth transited from nuclear to thermonuclear+renewables in my vision of the future (ITER was successful with the claimed 20:1 rates; 100:1 rates and greater were achieved in subsequent commercial plants and a lot of power systems we use now went the way of the dodo). Not sure if that will happen in reality, but that's what imagination's for.



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 10:01am
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Stas Bush wrote:
Orions in my view are not a commercial vessel; they are an exploration vessel and a passenger system ferry, used to cover huge distances quickly
maybe I was not clear. Are they run with a profit or with a loss? By a private company or by the US/USSR government?

Stas Bush wrote:
someone_else wrote:
The cost is very likely to make them completely uneconomic, imho. wikipedia says that estimates were around 300'000 modern dollars per bomb, and all designs needed something like 800 bombs just to reach orbit. 240 million dollars only for the fuel to fucking reach orbit.
They should be assembled in space, ideally, not to worry about aerodynamics and wasting bombs to raise them up. How many bombs would the ship need to get from Earth orbit to Mars orbit?
learn to read, this is the second time you as what I clearly stated. Just below what you quoted I said:
-you use atmosphere as propellant
-the delta-v needed to get anywhere in a speed worth using Boom-Boom-Orion is 3-4 times that of reaching orbit.

Since delta-v to reach orbit is somewhere around 10-11 km/s and 3-4 times that is 30-40 km/s... Which is relatively crappy for a true high-speed transit, but should bring you to Mars in 3 months.

Anyway, you need somewhere like 2400-3200 bombs for a one-way trip to inner system destinations (Mars, venus, mercury, asteroid belt), or say 4800 bombs to go to Jupiter with something like 8 months of coasting. And you cannot do much better than that, my spreadsheet tells me you'd have a payload below 0 kg already.

That is with the relatively realistic Orion designs, before they pull really weird shit out of nowhere.

The kinetic impactors I talked of above can keep accelerating your ass for as long as you want them to (you can pull brachistochrones! Yay!), with a Ve which is a little less than double that of an Orion at optimal conditions, which means they basically beat the crap out of Orion performance-wise for a fraction of the cost (especially if you can make them with ISRU and just ship the electronics from Earth). The only difference is that you have to book the flight a year or so of time ahead of the departure, not even Orions can dramatically change their course.

Also, the swarm of kinetic impactors can have military uses as well, since it can basically sweep away any orbital asset, and any asset on the ground not protected by an atmosphere. Also do a good job at intercepting whatever wants to hit the vessel that is using them as propulsion.

Takes a damn while to get them to the target, but it's something that can be used as space-equivalent of ICBMs for space assets that don't move much faster either.


Quote:
Yeah, that was with the Daedalus ICF project.
No. Daedalus was using pellets ignited by lasers or electron beams or whatever and a magnetic nozzle.

PeZook wrote:
Of course, I have to wonder about our fissile reserves if we decided to use Orions to set up a Mars colony
To solve the radioactives problem I'd either start fucking with thorium (it's relatively abundant in the solar system and on Earth, you can use it to breed U233 which can be used to make nukes or fissioned to produce power in a reactor, not so easy as it sounds but doable) or go to fully-fledged fusion bombs.

Quote:
Also, Earth transited from nuclear to thermonuclear+renewables in my vision of the future (ITER was successful with the claimed 20:1 rates; 100:1 rates and greater were achieved in subsequent commercial plants and a lot of power systems we use now went the way of the dodo). Not sure if that will happen in reality, but that's what imagination's for.
If magnetically-confined fusion (which is a major pain in the ass) is a reality, why not using that to build a fusion torch instead of Orion?

Btw, I thought ITER wasn't supposed to be a real power generator, to achieve that with magnetic confinement it should have been much bigger.



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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 10:05am
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ITER will have the potential to yield energy but won't be hooked up to anyone's electrical grid; it's like some of the early research "atomic piles" of the late 1940s, necessary prototypes of the modern nuclear reactor but not themselves reactors in the modern sense. However, extracting electricity from the reaction is a relatively well understood problem, compared to just getting the reaction to run in the first place. So a success of ITER constitutes a promising sign of success for future fusion reactors, so long as we keep at it.

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 10:35am
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Stas Bush: I feel like cut'n'rebutt is taking this off into a million unrelated tangents, so instead I will just rephrase my argument in more concise and hopefully more convincing way:

In 1890 no one knew how to build a rocket that would take a man into space. We can say that it was beyond their capability. No amount of time, with their fixed 1890 scientific knowledge and industrial base, would fix this. In 1960, it was done. In 2010, we are in at worst the same position we were when Saturn V program started. In fact we are in a better position, because we have in addition all the technical knowledge and experience from the Saturn V program, and also subsequent scientific, technological and industrial advances. It therefore would take us less time, be cheaper, better, or all of those.

That is what is generally considered to be meant by progress.

Simon_Jester wrote:
ITER will have the potential to yield energy but won't be hooked up to anyone's electrical grid; it's like some of the early research "atomic piles" of the late 1940s, necessary prototypes of the modern nuclear reactor but not themselves reactors in the modern sense. However, extracting electricity from the reaction is a relatively well understood problem, compared to just getting the reaction to run in the first place. So a success of ITER constitutes a promising sign of success for future fusion reactors, so long as we keep at it.

Really?

Well there are a couple of issues. It's not just a matter of hooking it to a turbine. ITER will only run for a few minutes (albeit at 500MW, comparable to a real power plant), which is a lot longer than other fusion experiments, but insufficient for a power reactor. Second, there is the issue of how to sustain neutron bombardment for long periods. Finally, the only way to make enough tritium to fuel the reactor is to breed it from lithium, and while this is based on old physics, the implementation has not been tried before.

Most people now see getting fusion to 'work' as mainly an engineering challenge, although getting it to work 'well' maybe is still a physics one.

---

Im not sure MCF is great for spacecraft. It's quite fiddly and temperamental. All fusion is quite sketchy as a space power source, really. Fission is much more now than sometime in next 2 centuries.

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 01:47pm
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Have we not solved the issue with tritium supplies for sustained fusion commercial output? I have read reports from 2007 and 2009 casting doubts on our capabilities for the foreseeable future, as the tritium breeding technologies to produce ample supply for expanding fusion reactor numbers is still vapour ware.

Incidentally, Bob Hirsch dismisses fusion entirely in favour of fission.

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 Post subject: Re: Why Not Space? [Op-Ed] PostPosted: 2012-04-04 04:46pm
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HMS Conqueror wrote:
Stas Bush: I feel like cut'n'rebutt is taking this off into a million unrelated tangents, so instead I will just rephrase my argument in more concise and hopefully more convincing way:

In 1890 no one knew how to build a rocket that would take a man into space. We can say that it was beyond their capability. No amount of time, with their fixed 1890 scientific knowledge and industrial base, would fix this. In 1960, it was done. In 2010, we are in at worst the same position we were when Saturn V program started. In fact we are in a better position, because we have in addition all the technical knowledge and experience from the Saturn V program, and also subsequent scientific, technological and industrial advances. It therefore would take us less time, be cheaper, better, or all of those.

That is what is generally considered to be meant by progress.
It would be better, probably. It would not be cheaper or quicker because the approach toward engineering has changed- we build more cautiously and allow management more free rein to impose red tape on innovators than we did in the 1960s.

Not all regulatory burdens come from the public sector...

Quote:
Simon_Jester wrote:
ITER will have the potential to yield energy but won't be hooked up to anyone's electrical grid; it's like some of the early research "atomic piles" of the late 1940s, necessary prototypes of the modern nuclear reactor but not themselves reactors in the modern sense. However, extracting electricity from the reaction is a relatively well understood problem, compared to just getting the reaction to run in the first place. So a success of ITER constitutes a promising sign of success for future fusion reactors, so long as we keep at it.
Really?

Well there are a couple of issues. It's not just a matter of hooking it to a turbine.
It kind of is- there's a cooling jacket around ITER that draws heat straight off. Since ITER is a research reactor, they just bleed the heat off into radiators, but you could totally hook a turbine to that.

Quote:
ITER will only run for a few minutes (albeit at 500MW, comparable to a real power plant), which is a lot longer than other fusion experiments, but insufficient for a power reactor.
Since the reaction produces heat, I suspect that if you can make it run in long enough bursts you don't have to run the fusion reaction continuously- just keep hitting it in bursts and keep the reactor temperature topped off.

Quote:
Second, there is the issue of how to sustain neutron bombardment for long periods.
If you mean what I think you mean, I know ways to bathe a target in neutron beams indefinitely for a relatively limited cost of power input. I once saw an interesting poster on using a method like that as a turbocharger-analogue for a molten salt reactor.

Most people now see getting fusion to 'work' as mainly an engineering challenge, although getting it to work 'well' maybe is still a physics one.[/quote]The guys who work in the field are reasonably optimistic now- they have the physics nailed down well enough to make the reactor work, and the engineering is just expensive, now that the computer technology is up to making it all designable.

Quote:
Im not sure MCF is great for spacecraft. It's quite fiddly and temperamental.
It's also very, very large... Nuclear reactors scale down a little better.

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