Rockets!

If polywell fusion is developed, in what ways will the world change for better or worse? Discuss.

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ANTIcarrot
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Postby ANTIcarrot » Fri Aug 17, 2007 11:08 pm

Zixinus wrote:You know what pisses me off? Emotional appeal. If you say "think of the children" then you are appealing to emotion, not reason.


Wash your mouth out with soap and water. And your keyboard too while you're at it.

And you know what annoys me? Idiots who can't recognize a logical argument when they see one. It doesn't matter what you or I think. Without significant political changes no nuclear engine will never be allowed to fly in western airspace. That's blunt reality I'm afraid.

We can design RTGs to survive re-entry and hard fall. We can design a fusion core to not release any radioactive material.


Try looking up the history of aircraft accidents before saying things like this. Or do the math for the blunt body reentry system you're proposing, and the mechanical considerations of it flying sideways at hypersonic speeds. That's what destroyed Challenger. As a guess, weight would be prohibitive.

We are talking about involounterly transmutated material, reactor components, that most likely will fairly quickly transmutate into stable materials.


That does not tally with what I've read elsewhere. Do you have evidence for this statement?

Furthermore, the ramjet idea does work,


But not as advertised. :roll:

Dude, HE'S A frick NUCLEAR ENGINEER AND PHYSICIST, not an artist.


One) Please don't use words like 'dude' in a technical discussion
Two) Don't shout
Three) Pick up a dictionary and look up the concept 'joke'. If you feel up to it, afterwards you can look up the concept 'education'. You may find the latter useful.

And for all practical purposes, there will be no neutrons.


Right. Because everyone knows a 10MW neutron flux never hurt anyone.

The paper, it discusses sample missions, which contain allowances for everything but shielding. Though if you want to show how you can shoehorn shield and useful payload into the 70MT he allows, I'd be interested.
Some light reading material: Half Way To Anywhere, The Rocket Company, Space Technology, The High Fronter, Of Wolves And Men, Light On Shattered Water, The Ultimate Weapon, any Janes Guide, GURPS Bio-Tech, ALIENS Technical Manual, The God Delusion.

MSimon
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Shielding

Postby MSimon » Fri Aug 17, 2007 11:17 pm

If you use water as the reaction mass it will provide more than adequate neutron shielding.

Nanos
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Postby Nanos » Sat Aug 18, 2007 11:30 am

> Without significant political changes no nuclear engine will
> never be allowed to fly in western airspace

Then fly it elsewhere.

ANTIcarrot
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Re: Shielding

Postby ANTIcarrot » Sat Aug 18, 2007 2:56 pm

MSimon wrote:If you use water as the reaction mass it will provide more than adequate neutron shielding.


And the people on the ground as it flys low for take off or landing? This is one of those 'non technical' problems with HTOL SSTO I mentioned earlier. 747 runways have very large noise footprints. You're looking at a vehicle that could produce a larger noise footprint and a comparable irradiation footprint. You've also mentioned a ten day cooling down period for steel 404. How will this affect ground operations? After flight inspections for example?

Will it be a case of land it, run away fast, then wait a month before going near it again? That's beginning to sound like the US space shuttle. ;)
Some light reading material: Half Way To Anywhere, The Rocket Company, Space Technology, The High Fronter, Of Wolves And Men, Light On Shattered Water, The Ultimate Weapon, any Janes Guide, GURPS Bio-Tech, ALIENS Technical Manual, The God Delusion.

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Re: Shielding

Postby MSimon » Sat Aug 18, 2007 3:18 pm

ANTIcarrot wrote:
MSimon wrote:If you use water as the reaction mass it will provide more than adequate neutron shielding.


And the people on the ground as it flys low for take off or landing? This is one of those 'non technical' problems with HTOL SSTO I mentioned earlier. 747 runways have very large noise footprints. You're looking at a vehicle that could produce a larger noise footprint and a comparable irradiation footprint. You've also mentioned a ten day cooling down period for steel 404. How will this affect ground operations? After flight inspections for example?

Will it be a case of land it, run away fast, then wait a month before going near it again? That's beginning to sound like the US space shuttle. ;)


I see your point.

If you are within a hundred feet of the rocket when it takes off the radiation could kill you.

Probably best to stand further away.

BTW the 10 day cool down is the requirement after months of continuous operation at high power. The cool down from a 10 minute trip to orbit will not be as long.

ANTIcarrot
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Re: Shielding

Postby ANTIcarrot » Sat Aug 18, 2007 4:35 pm

MSimon wrote:I see your point. If you are within a hundred feet of the rocket when it takes off the radiation could kill you.


I was also thinking of people standing a mile or more below the flight path and being exposed four or five times a day for thirty years. Only without the sarcasm.
Last edited by ANTIcarrot on Sat Aug 18, 2007 7:24 pm, edited 1 time in total.
Some light reading material: Half Way To Anywhere, The Rocket Company, Space Technology, The High Fronter, Of Wolves And Men, Light On Shattered Water, The Ultimate Weapon, any Janes Guide, GURPS Bio-Tech, ALIENS Technical Manual, The God Delusion.

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Re: Shielding

Postby MSimon » Sat Aug 18, 2007 6:21 pm

ANTIcarrot wrote:
MSimon wrote:
ANTIcarrot wrote:
MSimon wrote:I see your point. If you are within a hundred feet of the rocket when it takes off the radiation could kill you.


I was also thinking of standing a mile or more below the flight path and being exposed four or five times a day for thirty years. Only without the sarcasm.


You know I believe that is why most rockets are situated to fly over water for the early part of their flights.

ANTIcarrot
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Re: Shielding

Postby ANTIcarrot » Sun Aug 19, 2007 6:29 pm

MSimon wrote:You know I believe that is why most rockets are situated to fly over water for the early part of their flights.


You know I believe you haven't actually seen Mr Bussard's proposals for SSTO, have you?

The need for coastal launch/recovery facilities is another one of those minor engineering problems you seem blissfully ignorant of. In fact it's also one of the major engineering problems that could prevent launch costs from coming down anywhere near as far as he claims. And if you know anything about the history of the kennedy space center, or the history of launch vehicle development, you'd understand that.

If don't understand the problem involved in bring down launch costs, you're welcome to say so. You're also welcome to go away and do research until you don. But I'd ask you to stop going 'LOL!' every time a problem comes up that you don't have the education to recognise.
Some light reading material: Half Way To Anywhere, The Rocket Company, Space Technology, The High Fronter, Of Wolves And Men, Light On Shattered Water, The Ultimate Weapon, any Janes Guide, GURPS Bio-Tech, ALIENS Technical Manual, The God Delusion.

Zixinus
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Postby Zixinus » Sun Aug 19, 2007 8:08 pm

The need for coastal launch/recovery facilities is another one of those minor engineering problems you seem blissfully ignorant of.


And it is a problem of aerospace engineering, not of nuclear nor anything regarding the Polywell. I do not see how having a launch facility makes a Polywell-based rocket impossible.

Oh, wait, you are expecting Bussard to build the rocket?

EDIT:

And the response for your previous post:

Wash your mouth out with soap and water. And your keyboard too while you're at it.


My mouth (and keyboard for that matter) is as dirty as I like.

And you know what annoys me? Idiots who can't recognize a logical argument when they see one.


You had a logical argument? No, you had an appeal to emotion. That's not logical, that's a logical fallacy.
"Think of the children" when not actually talking about the issue of children and their care, is one of those political memes of politicians that want me to strangle them. It's pure nonsense, meant to throw you off balance in a debate. It's almost as bad as "How much plutonium do you recommend for a pregnant women?".

It doesn't matter what you or I think. Without significant political changes no nuclear engine will never be allowed to fly in western airspace. That's blunt reality I'm afraid.


And? We are not talking about the political reality of firing up a nuclear rocket. We are talking about the possibility.

Try looking up the history of aircraft accidents before saying things like this.


And look up the history of RTG's. One of them landed in the ocean, it survived re-entry, landed in the ocean, no radioactive leakage has been measured.
All American RTG's were designed and made to survive such an ordeal. What the rushed and lead by sheer incompetent Soviets made is altogether a different story.

I believe that a good-enough shielding ceramic can be made that is very difficult to crack, thus disallow leakage until cool-down time.

That does not tally with what I've read elsewhere. Do you have evidence for this statement?


You need evidence for common frick sense?

Over 80-90 % of a nuclear waste in a traditional fission reactor is leftovers of fuels that are decaying into lower-z radioactive materials that decay into even lower-z radioactive materials. Since we are not using high-z materials, whatever is activated by neutrons, will fairly quickly go back into stable state.
Low-z materails often have a much lower half-life and radioactivity then high-z materials.

But not as advertised. Rolling Eyes


By whom? The doctor or science fiction writers?

One) Please don't use words like 'dude' in a technical discussion


Why not?

Two) Don't shout


Who's shouting? I'm "bolding" my letters.

Three) Pick up a dictionary and look up the concept 'joke'. If you feel up to it, afterwards you can look up the concept 'education'. You may find the latter useful.


Pick up a dictionary yourself and try to find the meaning of the word "unfunny".

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Re: Shielding

Postby MSimon » Sun Aug 19, 2007 8:32 pm

ANTIcarrot wrote:
MSimon wrote:You know I believe that is why most rockets are situated to fly over water for the early part of their flights.


You know I believe you haven't actually seen Mr Bussard's proposals for SSTO, have you?

The need for coastal launch/recovery facilities is another one of those minor engineering problems you seem blissfully ignorant of. In fact it's also one of the major engineering problems that could prevent launch costs from coming down anywhere near as far as he claims. And if you know anything about the history of the kennedy space center, or the history of launch vehicle development, you'd understand that.

If don't understand the problem involved in bring down launch costs, you're welcome to say so. You're also welcome to go away and do research until you don. But I'd ask you to stop going 'LOL!' every time a problem comes up that you don't have the education to recognise.


LOL

I guess you have never heard of the Kennedy Space Center.

Or ocean launches.

For a guy with such a wild imagination on WMDs your mind seems incapable of imagining anything besides a launch from Omaha.

LOL

BTW for no education you better hope I did my job right as an aerospace engineer. You might be flying on an aircraft that depends on my code or hardware.

LOL

Well there will always be idiots like you. Better to deal with them sooner than later.

Y'all come back again ya'hear?

LOL

ANTIcarrot
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Postby ANTIcarrot » Sun Aug 26, 2007 11:17 pm

Zixinus wrote:And it is a problem of aerospace engineering, not of nuclear nor anything regarding the Polywell.


The whole 'implications' sign you might have missed on the way in. Talking about why certain outcomes are very unlikely is well within the remit of this forum.

Oh, wait, you are expecting Bussard to build the rocket?


What part of 'this is his own personal proposal that he has come up with and promoted in his talks' do you not understand?

My mouth (and keyboard for that matter) is as dirty as I like.


Then sooner or later you'll earn yourself a nice little BANNED notice underneath your name. This is a discussion board; not a playground and not your own personal front room.

You had a logical argument? No, you had an appeal to emotion. That's not logical, that's a logical fallacy.


Believing that things you don't like aren't real and can't hurt you is foolish. This sentiment exists and is popular in the general public of most nations capable of building such machinery. Hence for all intents and purposes it is an engineering requirement that needs to be addressed by any successful design.

And look up the history of RTG's.


Apples and oranges. RTGs are solid devices. Because of that they can be made as strong as bank vaults. Polywells cannot be built that way because they require so much empty space inside them.

You need evidence for common frick sense?


The problem is that it's not common sense. The radiation will not just affect the reactor components but everything else around the aft of the ship.

This is a nuclear reactor of a size that no one has ever built, using a method humankind has about three hours accumulated operational experience with, surrounded by materials which have never been exposed nor designed to deal with any level of neutron flux, generating electricity for rocket concepts that no one has ever tested.

Common sense states that it's very unlikely that it will work as initially advertised. Science states that since you've never exposed a high pressure LH fuel pump (which barely work as it is) to intense neutron flux (which can create material flaws) for repeated flights you cannot categorically state there will be no problems.

Fission reactors provide no case study for these issues.

By whom? The doctor or science fiction writers?


Both. The initial overly optimistic ram-jet designs assumed certain things about interstellar gas which turned out not to be true. Hence even if such a machine could be built and the problems of controlling the magnetic scoop solved, it could never live up to his claims. It was a clever idea, but his claims about engine capability turned out to be inaccurate.
Some light reading material: Half Way To Anywhere, The Rocket Company, Space Technology, The High Fronter, Of Wolves And Men, Light On Shattered Water, The Ultimate Weapon, any Janes Guide, GURPS Bio-Tech, ALIENS Technical Manual, The God Delusion.

ANTIcarrot
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Re: Shielding

Postby ANTIcarrot » Sun Aug 26, 2007 11:40 pm

MSimon wrote:I guess you have never heard of the Kennedy Space Center.


Have you ever heard of Kings Cross? Famous railway station in London. Featured in the Harry Potter movies. Has the original Victorian engineered roof. Quite a lovely station. Has been in use for well over a hundred years. For most of that time, unlike the KSC or NASA, it was actually good for something and was able to pay its way. And despite all of that, it is still utterly irrelevant to later transport developments, like the car or the plane.

The KSC is similarly entirely not relevant to any kind of SSTO; the whole point of which would be to make such massive installations, and their design philosophies, largely redundant.

BTW for no education you better hope I did my job right as an aerospace engineer. You might be flying on an aircraft that depends on my code or hardware.


Being qualified to design an air-break, or a fuel valve, or mounting bracket, or even components of an autopilot control programme, does not automatically confer a detailed understanding of aircraft-operations, rocket science or economics. It can be a good foundation, but that's all it is.
Some light reading material: Half Way To Anywhere, The Rocket Company, Space Technology, The High Fronter, Of Wolves And Men, Light On Shattered Water, The Ultimate Weapon, any Janes Guide, GURPS Bio-Tech, ALIENS Technical Manual, The God Delusion.

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Re: Shielding

Postby MSimon » Mon Aug 27, 2007 12:37 am

Being qualified to design an air-break, or a fuel valve, or mounting bracket, or even components of an autopilot control programme, does not automatically confer a detailed understanding of aircraft-operations, rocket science or economics. It can be a good foundation, but that's all it is.


Except for one minor detail.

Aircraft operations were part of the spec. Note that a good engineer will question the specs based on understanding of the whole system.

BTW Engineers in for profit companies MUST understand at least micro-economics. Of course that includes a fair bit of macro as well.

In addition even something as simple as a valve can't be WELL designed unless you understand how it fits into the big picture i.e. what are the trade-offs and how do they influence other systems in the aircraft.

Especially today with most of the functions that used to be performed by a flight engineer get handled in software.

===========

Now there you go changing the Kennedy/oceans question from one of location to that of NASA competence.

Stick to the subject:

Relative to launching over the ocean:

1. Have you heard of Kennedy and its location?
2. Have you heard of launching from the ocean?

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Re: Shielding

Postby ANTIcarrot » Mon Aug 27, 2007 12:47 pm

MSimon wrote:Except for one minor detail.


And yet you still believe nuclear power aircraft would ever get built?

Try just for a moment to apply your vaunted education (aircraft operations especially) to space shuttle programme, and try and see what is wrong with that picture. Nothing in real life comes so close to resembling a penrose triangle.

Stick to the subject:


People in glass houses shouldn't throw stones. And people with one strike already should not throw personal insults about.

The KSC today boils down to LC39 and the visitor's center. One is a worthless pile of junk designed to appeal to those who lack any understanding of rocket science, and the exhibits in the other haven't been changed in ten years. LC39 and its associated programmes have warped everything NASA has done for the past 30 years. It's a $10B a year millstone round their necks they can't get rid off; and which they have almost started to worship, like a religious icon.

Sea Launch is vast improvement on that, but still it has stupidly high costs. And it's still dependent on artillery-driven mentality, and it's still located in an intensively corrosive environment, and relies on huge and expensive pieces of equipment, and is optimised for only one kind of rocket, and can barely manage two or three launches a year.

Neither has any relevance to low cost space flight or SSTO.
Some light reading material: Half Way To Anywhere, The Rocket Company, Space Technology, The High Fronter, Of Wolves And Men, Light On Shattered Water, The Ultimate Weapon, any Janes Guide, GURPS Bio-Tech, ALIENS Technical Manual, The God Delusion.

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Postby MSimon » Mon Aug 27, 2007 2:35 pm

Were we discussing nuclear powered aircraft in the thread? I don't seem to be able to find that discussion. Perhaps you can point it out to me.

You are personally insulted by a request to stay on topic? OK. I'll keep that in mind.

My point about the Kennedy Space Center is that it is a place on land that allows you to launch over water so that you can keep humans out of the maximum danger zone. That is not the only such place. I can see I did not explain it clearly enough for you to understand. My apologies.


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