Is going to space really going to be a pipe dream and for scfi due to this?

[Mr Skeptic]

The reactor in the "nuclear lightbulb" is a gas reactor. It won't melt down because it is a gas. If it overproduces energy, it will simply expand, reducing the density and so slowing the reaction. It needs to have a separate storage container, full of control rods and impact-resistant, where the uranium hexafluoride can be put to either turn it off or in case of problems.

 

Many rockets use highly toxic materials for fuel or oxidizer. The nuclear lightbulb uses hydrogen.

[InigoMontoya]

Possibly you missed the link I provided?

 

Just read it.

 

Umm... Where to begin?

 

The author really is into spin and half truths.

 

He mentions ground testing of NTR and quotes performance numbers that other sites list as "max theory" and such and are NOT actually measured performance. But he says the numbers he quotes are demonstrated. Mind you, in the actual numbers this one is almost a nitpick as the original design was quite good, but it speaks to his intellectual integrity.

 

He talks of the GCNR as if it's something that has been tested on the ground 50 years ago. His is the only site I can find that indicates a GCNR is anything other than theory.

 

He says that only something like 40 people died in Chernobyl and uses this as evidence that nukes are cool. Of course, he never mentions that the number 40 is HIGHLY debated and many estimates are in the thousands. Nor does he mention the large swaths of land that are deemed unsafe to inhabit as a result of the incident.

 

He talks about the GCNR running at insanely high temperatures and how such heat can be transmitted to the reaction mass (hydrogen is NOT fuel, despite him calling it that; it's reaction mass!) via radiation, but there's never any mention of conduction effects on containment or nozzle design.

 

Basically, he talks of cutting edge technologies and unproven ideas as if they're old hat and no big deal. "This will be easy!" seems to be his conclusion. Suffice to say that I think 150 years ago he'd have been wearing a top hat and driving a horse-drawn cart selling an elixur to cure what ails ya.

 

Is it possible? Maybe. My profession is chemical propulsion, not nuclear. However, based on a quick read and a cross referencing of key terms (ie, getting a second opinion on the state of the mentioned technologies and programs) my conclusion is that the author is a snake oil salesmen. Perhaps there are some better sites discussing the concept written by a more measured/balanced/honest author?

[Moontanman]

It's no more implausible than nuclear detonations or hydrogen fusion. As for a flying Chernobyl you really should read the article and it's take on risk mitigation. Having made my living at one time at Du Pont and being part of a very successful "risk mitigation" team you should know there is a big difference between the unexpected accident and the expected accident. As is quoted in the article one hydrogen bomb detonation released many times the radioactive debris of Chernobyl and no one died, Chernobyl is not a reasonable example of risk mitigation by any sense of the word and using it as such is nothing more than fear mongering.

[InigoMontoya]

My point isn't whether nuclear propulsion is plausible or not. My point is that the author makes claims that appear to be inaccurate (performance numbers for NTR) or complete fabrications (presenting GCNR as "already tested on the ground" when all other sources found in a quick google indicate that it is strictly a theory). This is not the hallmark of a trustworthy source.

 

My point isn't whether or not the consequences of Chernobyl were 5 people with broken fingernails or 100,000 people dead. My point is that the author cherry picked some data and conveniently ommitted other data. This is not the hallmark of a trustworthy source.

 

My point is that the author of that site is stretching the truth and spinning things at every opportunity. Maybe the author is correct in his conclusions. Maybe he's not. My point is that after cross referencing the presented data and ideas I'm left having no more faith in that site for scientific insight than I do Wyle E Coyote. His grossly biased presentation style leaves me questioning the veracity of everything he says. And so I ask again if you have any other sites that discuss the same topics in a more honest/balanced manner.

 

 

 

As for risk mitigation... I'm well versed in it. As I said, I am employed in the chemical propulsion industry. I deal with "What if this thing explodes?" on a daily basis and in fact have been witness to possibly hundreds of explosions (I'm guessing, it's not like I keep score) but zero injuries. That said... While it's true that separation distance is the cheapest and easiest risk mitigation strategy I think it's unfair to indirectly accuse the Ruskies of neglecting risk mitigation. Do you honestly think they would have built a plant with zero safety features? To say that it is an example of inadequate risk mitigation is fair. To say that their system (both engineering and personnel) failed is fair. To imply that there was zero risk mitigation on their part is ridiculous.

Edited March 21, 2010 by InigoMontoya

[nec209]

Moontanman no I do not believe any technology we have now or any thing cutting edge technology that may come out will allow 1000 tons payload into space.That is crack pot idea .

 

The payload is problem.No I do not believe any technology will allow more than 10 people to go up in space on a rocket.

 

No propulsion we have or know of will work.I was hopping that plasma propulsion,antimatter propulsion ,laser propulsion, explosion propulsion, fusion propulsion , ion propulsion or fission propulsion may fix this problem we have but no it will not.

 

 

The laws of physics does not allow more than 8 people to go up in space.

 

That put simple .

 

 

real world.

 

You need this

http://scienceblogs.com/startswithabang/upload/2009/12/the_perils_of_planet-hopping/A15SaturnV.jpg

 

to have this .

http://www.fly.co.uk/blog/wp-content/uploads/orion.jpg

 

 

And you want mass immigrants to go to moon or mars to live??? A under- water city or dome city to live and work on earth is more real than this.

 

 

Even if space plane on rocket like this could take 10 or 15 people up to the space station or craft in space and take that to the moon or mars would not work do to cost and not taking up enough people.

 

http://www.spacetoday.org/images/SpcShtls/SpacePlane/OrbitalSpacePlaneLaunch600x450.jpg

 

It have to be $2,000 per person and craft that can take up 50 or 100 people and it not going happen now or any thing on the drawing board we have now .The laws of physics just seem to not work this way.

 

After doing some more reading that put it simple space is for probes and going to the moon or mars to visit not to stay and by astronauts that cost $$$$$ only the state can pay!!!That is all !!

 

No propulsion we have or know of on the drawing board like plasma propulsion,antimatter propulsion ,laser propulsion, explosion propulsion, fusion propulsion , ion propulsion or fission propulsion will fix this problem .

Edited March 21, 2010 by nec209

[Mr Skeptic]

My point isn't whether nuclear propulsion is plausible or not. My point is that the author makes claims that appear to be inaccurate (performance numbers for NTR) or complete fabrications (presenting GCNR as "already tested on the ground" when all other sources found in a quick google indicate that it is strictly a theory). This is not the hallmark of a trustworthy source.

 

Do you mean this:?

As I mentioned above, way back in the 60's NERVA and ROVER made nuclear powered rockets. These rockets were thoroughly tested and were able to generate as much as 250,000 pounds of thrust, with an Isp of 900 seconds or better. The best chemical fuels in use today are liquid hydrogen and liquid oxygen, the stuff burned by the three Main Engines on the Space Shuttle (SSME's). The SSME's produce a maximum of about 450 Isp.

 

These were real projects testing nuclear propulsion. It was not gas core, but it was nuclear.

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Moontanman no I do not believe any technology we have now or any thing cutting edge technology that may come out will allow 1000 tons payload into space.That is crack pot idea .

 

How so? Just make a bigger rocket. Or a better rocket (nuclear). Or even without a rocket (space elevator or launch loop).

 

And you want mass immigrants to go to moon or mars to live??? A under- water city or dome city to live and work on earth is more real than this.

 

Easier, sure, but also more boring. Also it's more expensive than living elsewhere on earth, but in space there is no really cheap place to live so there is no comparison -- it's either on earth, or expensive.

[InigoMontoya]

Do you mean this:?

As I mentioned above, way back in the 60's NERVA and ROVER made nuclear powered rockets. These rockets were thoroughly tested and were able to generate as much as 250,000 pounds of thrust, with an Isp of 900 seconds or better. The best chemical fuels in use today are liquid hydrogen and liquid oxygen, the stuff burned by the three Main Engines on the Space Shuttle (SSME's). The SSME's produce a maximum of about 450 Isp.

 

These were real projects testing nuclear propulsion. It was not gas core, but it was nuclear.

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No, however, that is the portion wherein I am criticizing the over statement of the performance of NTRs. He states an Isp of 900+, and yet over on wikipedia's NERVA page I find 825 s (vacuum).

 

Aside: Wiki also indicates an Isp of 380 s for sea-level. That's really pretty interesting. The engine must be running at very low pressure and it also might not be nearly as useful for getting to LEO as the vacuum impulse would imply.

 

But what I was talking about when I say the author of that page makes claims concerning rockets that - near as I can tell - have never existed beyond his claims are the following two quotes...

 

They built test models of the GCNR many years ago, and discovered a little problem.

Even though it seems impossible, the smart fellows back in the 70's actually built test models of this type of system and made it work.

 

 

 

 

PS: And in the event folks think I'm just a nuclear power hater, I am interested enough that I've actually been to both the NERVA test facility at White Sands (or what's left of it) as well as stood on the rim of Sedan Crater (still need to make it to Trinity for the trifecta but alas my kid decided to be born right before my only opportunity to date and I had to cancel.).

[nec209]

How so? Just make a bigger rocket. Or a better rocket (nuclear). Or even without a rocket (space elevator or launch loop).

 

 

Sure it may be possible to have bigger rocket or space capsule to take 10 or 15 people to the moon or mars but at what cost.

 

The space shuttle was nice idea but slap in NASA face with cost .The X-33 that was to replace the space shuttle was nice idea but again cost .The space plane on rocket sound like a good idea but cost.

 

 

NASA is even scaling back the apollo program to use one rocket for payload and one for people and smaller rocket!!! The mood that going on at NASA is built smaller ,simple and cheaper ways to go in space than bigger ,more conplex ways .

 

Cost is big factor .If money came from the sky every country could have a space shuttle and X-33 not say space station.

 

We may be able to built bigger rockets and bigger space capsule but the cost is factor.

 

It cheaper to bult smaller ,simple rockets and smaller capsule than big capsule .

 

 

I know there are many research going into space planes where it takes off like plane to x number of altitude and the rocket kicks in.Others are space planes on rocket .Some are looking at attaching a space plane to airplane and use airplane to take the space planes up to number of altitude than the space planes un-hooks and shoots of.

 

Other people are looking at SSTO like the DC-X and some looking at Kliper a partly reusable manned spacecraft.

 

But other than research I do not think any country will go this way but old way of going up. On less there is other cold war I do not think you will see any country going this way .

 

Why the old way? It simpler ,cheaper to built ,test and use .The other way need research and cost more and more conplex to built and use .

 

 

So space planes ,DC-X ,x-33 ,Kliper ,rocket combo planes and space shuttle sound nice but too costly:eek:

 

Other than research I do not think any country will go this path to do cost but take the old path like before.In fact even the old way that is simpler ,less conplex ,cost less :eek: Is too costly !!!

[JohnB]

My 2 cents.

 

Moontanman, I thought the page was a bit "simplistic" in presentation of his ideas. But the ideas certainly seemed basically plausible.

 

Inigo (and no, I don't have 6 fingers on my right hand) while Chernobyl was brought up as risk management, I think he was getting at a deeper point.

 

For many people "nuclear" is a very scary word. There is a tremendous lack of education in the area. People will go an anti-nuclear rally because they are scared of "radiation" and then go home and cook dinner in the microwave.

 

To make such a vehicle politically acceptable, the public needs to understand the difference between the engine gas which is radioactive and the exhaust, which is not.

 

We face a similar thing in australia. The green groups want our only reactor at Lucas Heights shut down because nuclear = bad. Lucas Heights produces the short lived isotopes used in medicine and that is all it does. Through poor education and faulty logic, there are people that want the advantages of modern society, but are against the things that produce that society.

 

They want solar power, but don't want sand mining. They want clean Hydro power but are against building dams. They want wind power but are against wind farms. These views and fears are irrational and can only be combatted by education.

 

I think the page author was trying (not too well) to put a few things in perspective and give a bit of education.

 

Whether or not he is correct in his assertions about such a propulsion system is another matter. However, if it could be built and made safe, then it would certainly bear consideration and further research.

 

One of the problems in this area is that both governments and business want relatively quick returns. Neither think in terms of 20-30 years, politicians don't think past the next election.

 

The idea of spending large amounts of money to send AI factories to the asteroids so that in 15 years refined metals will start coming to NEO is unsound to politicians. There would be a lot of lobbyists demanding that the money be spent now on other things. "We can explore when we've fixed the problems here" type of thing. Of course, that sort of thinking a couple of hundred years ago would have precluded the colonisation of both the US and Australia.

 

Psychology plays an important part in politics, and the exploration of space is a political, not scientific funding fight. One good argument for sending men "out there" is that it is hard to cut the funding later. Robots? Who cares, they'll stop eventually and nobody will cry. But even a small manned base has the psychological impetus of "They're heroes. We can't just leave them to die!"

 

Just my 2c.

[Icefire]

Truth.

And the really nice thing about working in space is that pretty soon (relatively) we would have a self-sustaining moonside colony in the case that the UN self-destructed or something else happens that threatens humanity.

not that it will ever happen, and if 2012 is true then we're doomed anyways.

[toastywombel]

An orbital elevator not only requires engineering on a scale that has never even been attempted before, it also requires a massive counterweight at a very high orbit. How are you going to get that counterweight up there?

 

There are no free lunches.

 

Actually the creation of the universe seems to be the biggest free lunch of all.

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Moontanman no I do not believe any technology we have now or any thing cutting edge technology that may come out will allow 1000 tons payload into space.That is crack pot idea .

 

The payload is problem.No I do not believe any technology will allow more than 10 people to go up in space on a rocket.

 

No propulsion we have or know of will work.I was hopping that plasma propulsion,antimatter propulsion ,laser propulsion, explosion propulsion, fusion propulsion , ion propulsion or fission propulsion may fix this problem we have but no it will not.

 

 

The laws of physics does not allow more than 8 people to go up in space.

 

That put simple .

 

 

real world.

 

You need this

http://scienceblogs.com/startswithabang/upload/2009/12/the_perils_of_planet-hopping/A15SaturnV.jpg

 

to have this .

http://www.fly.co.uk/blog/wp-content/uploads/orion.jpg

 

 

And you want mass immigrants to go to moon or mars to live??? A under- water city or dome city to live and work on earth is more real than this.

 

 

Even if space plane on rocket like this could take 10 or 15 people up to the space station or craft in space and take that to the moon or mars would not work do to cost and not taking up enough people.

 

http://www.spacetoday.org/images/SpcShtls/SpacePlane/OrbitalSpacePlaneLaunch600x450.jpg

 

It have to be $2,000 per person and craft that can take up 50 or 100 people and it not going happen now or any thing on the drawing board we have now .The laws of physics just seem to not work this way.

 

After doing some more reading that put it simple space is for probes and going to the moon or mars to visit not to stay and by astronauts that cost $$$$$ only the state can pay!!!That is all !!

 

No propulsion we have or know of on the drawing board like plasma propulsion,antimatter propulsion ,laser propulsion, explosion propulsion, fusion propulsion , ion propulsion or fission propulsion will fix this problem .

 

"Space Shuttle Discovery launches at the start of STS-120. ... A typical payload capacity is about 22700 kilograms (50000 lb), but can be raised depending on ..."

 

http://en.wikipedia.org/wiki/Space_Shuttle

 

That is 25 tons, so as far a a 1000 ton payload maybe not, but to say that the laws of physics don't allow for more than eight people to go into space is ridiculous. Unless you can show me the Max people allowed to go into space law.

 

Also it is good to note that fusion technology is not that far off. We have already created sustained fusion reactions that are contained by magnetic fields. The problem right now is they aren't efficient (it takes more energy to contain the reaction than you can get out of it).

 

But. . .

 

"On May 30, 2009, the US Lawrence Livermore National Laboratory (LLNL), primarily a weapons lab, announced the creation of a high-energy laser system, the National Ignition Facility, which can heat hydrogen atoms to temperatures only existing in nature in the cores of stars. The new laser is expected to have the ability to produce, for the first time, more energy from controlled, inertially-confined nuclear fusion than was required to initiate the reaction.[21]"

 

http://www.breitbart.com/article.php?id=CNG.12fab6f6c00a65e15e6fb5e305aacbb7.41&show_article=1

[Radical Edward]

An orbital elevator not only requires engineering on a scale that has never even been attempted before, it also requires a massive counterweight at a very high orbit. How are you going to get that counterweight up there?

 

there are already plenty up there. bringing them down would be far easier.

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That is 25 tons, so as far a a 1000 ton payload maybe not, but to say that the laws of physics don't allow for more than eight people to go into space is ridiculous. Unless you can show me the Max people allowed to go into space law.

 

Also it is good to note that fusion technology is not that far off. We have already created sustained fusion reactions that are contained by magnetic fields. The problem right now is they aren't efficient (it takes more energy to contain the reaction than you can get out of it).

 

But. . .

 

"On May 30, 2009, the US Lawrence Livermore National Laboratory (LLNL), primarily a weapons lab, announced the creation of a high-energy laser system, the National Ignition Facility, which can heat hydrogen atoms to temperatures only existing in nature in the cores of stars. The new laser is expected to have the ability to produce, for the first time, more energy from controlled, inertially-confined nuclear fusion than was required to initiate the reaction.[21]"

 

http://www.breitbart.com/article.php?id=CNG.12fab6f6c00a65e15e6fb5e305aacbb7.41&show_article=1

 

it's also the size of a warehouse.

 

You really don't want to be using fusion or fission to get things into orbit. You are far better off with very long linear accelerators, which you then run up the side of a mountain for launch. High repeat rates, you leave all (or most) of your energy grid on the ground and so on.

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And why would that be? Risk mitigation can deal with any risks involved.

 

You know there is a reason that they wanted to stop in-atmosphere nuclear testing? Risk mitigation can't deal with the ridiculous amounts of nuclear fallout that this would cause.

[InigoMontoya]

there are already plenty up there. bringing them down would be far easier.

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You'll excuse my laughter, I hope.

 

TomAto.

 

TomAHto.

 

Whether we're talking about sending 1000 tons into space from the surface or moving a 1000 ton near-Earth asteroid into a geocentric orbit of our choosing makes little difference. Both require propulsion systems so far beyond anything realistically on the horizon of our grandkids as to make the discussion laughable in our lifetimes.

 

 

You know there is a reason that they wanted to stop in-atmosphere nuclear testing? Risk mitigation can't deal with the ridiculous amounts of nuclear fallout that this would cause.

To be fair, a properly operating nuclear rocket does not release radiation whereas a properly functioning in-atmosphere nuclear detonation can not make such claims. For the nuclear rocket, one must only plan for the (hopefully) occassional accident; it's not as if it would be deliberately and repeatedly pumping all sorts of nasties into the environment.

 

That doesn't make it The Answer, mind you. It just means that particular risk should be managable to those who don't simply oppose nuclear power in the broadest sense.

[nec209]

That is 25 tons, so as far a a 1000 ton payload maybe not, but to say that the laws of physics don't allow for more than eight people to go into space is ridiculous. Unless you can show me the Max people allowed to go into space law.

 

 

 

Well 25 tons is a big difference than 1000 .Also the space shuttle and old apollo program are under attack has being too big and too conplex.The mood of NASA is build smaller and simpler .

 

If the space shuttle was big leep in saving money NASA would have had other space shuttle.In the 90's there was research into new shuttle and the x-33 was among them even smaller space shuttle than what they have now and all turn out non was economical.

 

MASA mood now is use smaller rockets one for payload and one for people than one big rocket for both.

 

Countries are not looking for bigger rockets and space shuttle but smaller and simpler.If money came from the sky than we can have bigger rockets and space shuttle. And spend $$$ every day on research.

 

After doing some more reading if in 5 or 10 years from now they send 10 or 15 people on rocket to the space station or the moon that would be a breakthrough.Now 50 or 100 people not going happen or 1000 tons.No propulsion we have or know of on the drawing board like plasma propulsion,antimatter propulsion ,laser propulsion, explosion propulsion, fusion propulsion , ion propulsion or fission propulsion will allow it.

 

If a SSTO like a DC-X will allow 3 people to go up to the space station that will be a big breakthrough !!

 

 

The propulsion we have or any thing on the drawing board even the once that are more scfi now like antimatter propulsion and fission propulsion will not allow it.The law of newton's third law does not allow big ships depict in scfi shows like star trek but the opposite.

 

Remenber boats and planes where dirt cheap and allowed bigger and bigger over time. This is not the case with rockets.A rocket we have now is like big cruise ship to launch a small capsule to the moon!! And you want 1000 ton payload into space.

[Airbrush]

Manned space missions will soon become unnecessary for missions to the near solar system, as technology advances in miniaturization and nanotech. A tiny robotic probe (TRP) will eventually have sensory capabilities of humans. The only problem is they will not be able to react in real time, like a human could. The controller will be restricted to long delays before initiating TRP action, while waiting for signals to travel back and forth at the speed of light. But for most missions to the near planets and asteroids, a TRP will be able do nearly as well as manned missions, and they save a lot of mass for life support, and thus can travel faster with more fuel and payload.

[nec209]

Looking for some good web sites and books on differnt propulsion and how rocket work

[Moontanman]

This is good one but I've posted it before.

 

http://www.nuclearspace.com/Liberty_ship_menupg.aspx

[InigoMontoya]

Looking for some good web sites and books on differnt propulsion and how rocket work

 

As one who's employed in the propulsion industry, if there's a universally accepted "Rocket Scientist's Bible," This is it.