For Questions That Don't Merit Their Own Thread

[Jacke]

20 minutes ago, SunlitZelkova said:

I may not have made it clear in the question, but this is supposed to be somewhere in the future where Starship is launching like crazy and costs have come down a bit.

If this is the case, how are we supposed to launch anything nuclear into space? Reactors are planned for Artemis and NTR development has started at DARPA.

I may not have made it clear in the question, but this is related to the future when launch costs may come down.

Launch vehicle costs will not drop that much.  There's a rule of thumb for a spacecraft, cost in 5 parts:

• standard spacecraft bus,
• mission components,
• launch vehicle,
• integration,
• launch site.

It's a misuse to just take something and waste what would be a non-zero cost of launching anything into space unless there's a purpose for it.

Also, as others have mentioned, nuclear waste drops in radioactivity very quickly.  It also has a lot of fissionable elements that should be reused and some reactor designs are very good at removing the middle-length half-life nuclei.

And currently nuclear waste is packaged in very good casks.  I personally feel it should just be stockpiled until there's a demand to reprocess it.  If people want to bury it, there's natural examples from Southern Africa that show open mineral formations don't have the waste move very far.

As for launching nuclear power sources or engines into space, that's been done before and will be done again when it's worth it.

[razark]

1 hour ago, SunlitZelkova said:

If this is the case, how are we supposed to launch anything nuclear into space?

Very carefully, and only when needed.

Also, a well built and protected reactor is going to be different from a barrel full of radioactive waste.

 

1 hour ago, SunlitZelkova said:

somewhere in the future where Starship is launching like crazy

"Launching like crazy" is very different from "reliable enough to be confident in not causing a major diplomatic crisis by dropping the largest dirty bomb ever devised on <insert random country/countries>".

[Gargamel]

One launch failure would be unacceptable.   Best case scenario it detonates on the pad, and keeps the fallout to a small area.   
 

Imagine what happens when a second stage booster fails to lite up and the waste falls from apogee, and the container burns up upon reentry?     We’ve now made a couple minor countries uninhabitable for a couple centuries.    Worst case scenario here is that it lands where most space refuse seems to land, Australia, and now those snakes and spiders are giant radioactive mutants and start over running the planet and nothing can stop them.   

Edited April 15, 2022 by Gargamel
Typo. Whoops

[darthgently]

19 minutes ago, Gargamel said:

One launch failure would be unacceptable.   Best case scenario it detonates on the pad, and keeps the fallout to a small area.   
 

Imagine what happens when a second stage booster fails to lite up and the waste falls from apogee, and the container burns up upon reentry?     We’ve now made a couple minor countries uninhabitable for a couple centuries.    Worst case scenario here is that it lands where most space refuse seems to land, Australia, and now those snakes are spiders are giant radioactive mutants and start over running the planet and nothing can stop them.   

I'm thinking that at minimum, a launch/ascent escape system for the payload, just as for a crewed mission, would be required.

Time for a Rad-Dragon to join Cargo-Dragon and Crew-Dragon

Edited April 15, 2022 by darthgently

[Gargamel]

8 minutes ago, darthgently said:

I'm thinking that at minimum, and launch/ascent escape system for the payload, just as for a crewed mission, would be required.

Oh, clearly, but that again reduces our usable payload to something even less efficient. 

[TheSaint]

And all of this would be because we're scared of just burying the stuff in the ground. Makes no sense at all.

[darthgently]

3 minutes ago, Gargamel said:

Oh, clearly, but that again reduces our usable payload to something even less efficient. 

True, but that is the cost of precious cargo, which a reactor would be.  It could be docked with the payload of other launches in orbit

Just now, TheSaint said:

And all of this would be because we're scared of just burying the stuff in the ground. Makes no sense at all.

Ok, maybe I didn't start far enough back in the thread.  I thought this was how to safely get a fueled nuclear reactor into space.  For nuclear waste on Earth, there are few things safer than the current ways we entomb and bury it deep.  There is zero reason to send nuclear waste to space

[darthgently]

Didn't geologists find a natural deposit of uranium that was working like a natural reactor in Africa?  Yeah, natural sources of radiation, like radon in basements, natural isotope byproducts of industrial processes, and potassium-40 naturally occurring in the food chain, etc. completely dwarf what is remotely detectable from entombed and buried nuclear waste
Here it is:

https://blogs.scientificamerican.com/guest-blog/natures-nuclear-reactors-the-2-billion-year-old-natural-fission-reactors-in-gabon-western-africa/

[StrandedonEarth]

8 minutes ago, darthgently said:

Didn't geologists find a natural deposit of uranium that was working like a natural reactor in Africa?  Yeah, natural sources of radiation, like radon in basements, natural isotope byproducts of industrial processes, and potassium-40 naturally occurring in the food chain, etc. completely dwarf what is remotely detectable from entombed and buried nuclear waste
Here it is:

https://blogs.scientificamerican.com/guest-blog/natures-nuclear-reactors-the-2-billion-year-old-natural-fission-reactors-in-gabon-western-africa/

Yes, I heard about that years ago. It probably helped evolution along by mutating anything that came close. The beneficial mutations survived and flourished! Is it any wonder that Africa has such diverse life forms, which led to the rise of the Homo genus?

Spoiler

That's probably why the Pak protectors chose to settle their breeders there...

 

Edited April 15, 2022 by StrandedonEarth

[darthgently]

9 minutes ago, StrandedonEarth said:

Yes, I heard about that years ago. It probably helped evolution along by mutating anything that came close.

Strangely enough, if I recall correctly, and I may not be, intense study of the Chernobyl area has found no significant evidence of DNA changes that are passed to the next generation.  There were some things that were more susceptible than others but generally the hazards were cancer to individual organisms exposed and very little if any significant changes to the next generation.  Of course the next generation could get direct damage from the environment, but not really via mutated DNA.  By far, most serious mutations that affect propagation cause failure to even produce offspring by way of direct damage.  Still no walk in the park for those directly exposed.

The Chernobyl area is a thriving wildlife refuge for all practical purposes.  But human immune systems are particularly vulnerable to radiation so not safe for humans

Here it is:

https://www.livescience.com/chernobyl-radiation-effects.html

Edited April 15, 2022 by darthgently

[StrandedonEarth]

2 minutes ago, darthgently said:

Strangely enough, if I recall correctly, and I may not be, intense study of the Chernobyl area has found no significant evidence of DNA changes that are passed to the next generation.  There were some things that were more susceptible than others but generally the hazards were cancer to individual organisms exposed and very little if any significant changes to the next generation.  Of course the next generation could get direct damage from the environment, but not really via mutated DNA.  By far, most serious mutations that affect propagation cause failure to even produce offspring by way of direct damage.  Still no walk in the park for those directly expose.

The Chernobyl area is a thriving wildlife refuge for all practical purposes.  But human immune systems are particularly vulnerable to radiation so not safe for humans

Here it is:

https://www.livescience.com/chernobyl-radiation-effects.html

Very true, but nonetheless the mutation rate would be increased, and with a large enough sample size over a long enough period, interesting things will eventually happen. It only takes one to thrive and propagate...

[darthgently]

10 minutes ago, StrandedonEarth said:

but nonetheless the mutation rate would be increased

So the theory says, but so far, no big amount evidence.  Researchers trying to induce evolution in the lab beyond very simple life forms have had very little luck using radiation from what I recall.  Or if the mutation rate is increased, the error checking and correction ability of the transcription process is far more robust than we imagined.  Actually, I think it is acknowledged now that the transcription error detection and correction process is in fact a lot more robust than thought only a few decades ago.  Evolutionary biologists are having to re-evaluate things a bit as mutation via radiation doesn't provide enough rate of change to explain current diversity so there must be some other mechanism at work.  A lot can be explained by sexual selection in both plants and animals and perhaps that played a larger role than previously thought

Edited April 15, 2022 by darthgently

[StrandedonEarth]

5 minutes ago, darthgently said:

So the theory says, but so far, no big amount evidence.

Ah, but it hasn’t had a few hundred million years yet. A million monkeys at a million typewriters for a million years, yada yada yada

[darthgently]

8 minutes ago, StrandedonEarth said:

Ah, but it hasn’t had a few hundred million years yet

The math can be projected and the mutation rate is currently not fully explained by what we know even given hundreds of millions of years.  It's ok to not know something.  It leaves something to discover, right?

8 minutes ago, StrandedonEarth said:

A million monkeys at a million typewriters for a million years, yada yada yada

 

8 minutes ago, StrandedonEarth said:

A million monkeys at a million typewriters for a million years, yada yada yada

A random number generator will produce gibberish a million years from now the same as it does a second from now.  There has to be a storage mechanism (DNA/RNA) and selection on changes.  The rate of the changes is what is hard to explain currently.  Or maybe that has changed.  The science around mutations that are passed on to the next generation is fairly unsettled in this regard and new insights are discovered all the time.  My personal hunch is that sexual selection will have a bigger role and viruses will probably have a bigger role than previously thought also (they do tinker with the transcription process)

Edited April 15, 2022 by darthgently

[K^2]

11 hours ago, JoeSchmuckatelli said:

Not interested in high ISP low thrust like NERVA but rather solutions to getting significant mass moved quicker. 

The limiting factor on NTR thrust is heat exchange and on I_SP the operating temperature. Both are primarily material limitations. I don't think you can do drastically better than NERVA. But it's already not terrible for interplanetary, where TWR isn't as important, so getting a bit more TWR out of it would let you cut the transfer time more, but we're still talking multiple months in transfer.

You might be able to do something creative like NTR with a chemical afterburner and magnetic nozzle. Theoretically you can get several times more thrust at comparable or even slightly higher I_SP, but we're deep in theoretical science territory with that one. Primarily, I'm not aware of a single design for a magnetic nozzle that would have been tested, and making it work with combustion products is problematic.

[kerbiloid]

4 hours ago, darthgently said:

Strangely enough, if I recall correctly, and I may not be, intense study of the Chernobyl area has found no significant evidence of DNA changes that are passed to the next generation

Have been eaten by the wolves coming from the neighboring forests to the nowolf's land.

First years after the event there were a lot of mutant photos from there, but mostly of insects and plants. Which have been replaced by their healthy counterparts from the neighbourhood, too.

The humans were evacuated, so were not exposed too long.

4 hours ago, darthgently said:

Still no walk in the park for those directly exposed.

A very spotty pattern of the pollution, with relatively safe passways and areas, and local hotspots close to each other.

4 hours ago, StrandedonEarth said:

Very true, but nonetheless the mutation rate would be increased, and with a large enough sample size over a long enough period, interesting things will eventually happen.

Once they happen, they get eaten.

As always, the belly rules.

Also, as ~100 rem disables the reproductive function iirc for a year or so, and higher or longer doses not just for a year, the most irradiated liquidators unlikely can provide us with children to study.

[DDE]

11 hours ago, darthgently said:

I'm thinking that at minimum, a launch/ascent escape system for the payload, just as for a crewed mission, would be required.

Time for a Rad-Dragon to join Cargo-Dragon and Crew-Dragon

You're not the only one. Some plans for an Angara A5-TEM stack feature a standard LES for the reactor core.

11 hours ago, darthgently said:

Strangely enough, if I recall correctly, and I may not be, intense study of the Chernobyl area has found no significant evidence of DNA changes that are passed to the next generation.  There were some things that were more susceptible than others but generally the hazards were cancer to individual organisms exposed and very little if any significant changes to the next generation.  Of course the next generation could get direct damage from the environment, but not really via mutated DNA.  By far, most serious mutations that affect propagation cause failure to even produce offspring by way of direct damage.  Still no walk in the park for those directly exposed.

The Chernobyl area is a thriving wildlife refuge for all practical purposes.  But human immune systems are particularly vulnerable to radiation so not safe for humans

Here it is:

https://www.livescience.com/chernobyl-radiation-effects.html

I think the studies started all the way after Hiroshima, i.e. before the "nuclear mutant" stereotype had spread.

[darthgently]

32 minutes ago, DDE said:

I think the studies started all the way after Hiroshima, i.e. before the "nuclear mutant" stereotype had spread.

Yes, I found links to that event also and there also no passed on mutations to speak of.  Though horrible for initial survivors from direct effects.

The Chernobyl situation is more illustrative for talking about nuclear power generation in particular and its incorrect scaling of its dangers in some ways. 

I think a lot of people see distorted phenotypes of people and animals and think those were from mutations passed on to another generation, but those are typically mutations that happened during pregnancy where the mother was pregnant during the exposure

Edited April 15, 2022 by darthgently

[JoeSchmuckatelli]

9 hours ago, K^2 said:

The limiting factor on NTR thrust is heat exchange and on I_SP the operating temperature. Both are primarily material limitations. I don't think you can do drastically better than NERVA. But it's already not terrible for interplanetary, where TWR isn't as important, so getting a bit more TWR out of it would let you cut the transfer time more, but we're still talking multiple months in transfer.

You might be able to do something creative like NTR with a chemical afterburner and magnetic nozzle. Theoretically you can get several times more thrust at comparable or even slightly higher I_SP, but we're deep in theoretical science territory with that one. Primarily, I'm not aware of a single design for a magnetic nozzle that would have been tested, and making it work with combustion products is problematic.

I cannot tell you how disappointed I am to learn this: I figured that (especially with some of the outlandish proposals) that we had some pretty good ideas waiting in the wings.  The way 'magnetic nozzle' gets thrown around, I guessed we were getting closer... but according to Princeton:

Quote

The mechanism by which plasma detaches from the applied magnetic field of the nozzle remains poorly understood. There are, however, many promising theories. Unfortunately, these theories involve complex plasma processes that are difficult to include within self-consistent analytical models. Furthermore, the plasma conditions under which these processes become dominant are difficult to characterize experimentally with conventional diagnostics. 

What I was really hoping for was a 'something' between using the fissiles to heat fuel and direct fission; that something like a fission-fragment rocket wasn't just sci-fi at the moment.

Nuclear Thermal Propulsion Systems - Glenn Research Center | NASA

718391main_Werka_2011_PhI_FFRE.pdf (nasa.gov)

Sadly, I don't have the education to do more than read these kind of things (simply); critical reading to understand the actual probabilities of success/ implementation are beyond me.

 

Thanks for the response!

 

 

[JoeSchmuckatelli]

12 hours ago, darthgently said:

Strangely enough, if I recall correctly, and I may not be, intense study of the Chernobyl area has found no significant evidence of DNA changes that are passed to the next generation. 

 

11 hours ago, StrandedonEarth said:

Very true, but nonetheless the mutation rate would be increased, and with a large enough sample size over a long enough period, interesting things will eventually happen. It only takes one to thrive and propagate...

My take-away from the Chernobyl findings is that the hot-spots are really just cooking stuff, not mutating it.

I recently posted this (longest running evolution experiment, video below) - which has some interesting findings about mutation.  They've been, for all intents and purposes, concentrating evolved members of the species together and 'breeding' successive generations from them.  (Lot more complicated, and they don't exactly talk about the details of the reproduction or delineate whether horizontal gene transfer is a factor).  But the concentration of evolved individuals and the eventual evolved ability to take advantage of a new food source are informative - as is the number of generations living in the confined environment before change occurs).

So - even if being exposed to a higher-than-normal background radiation in the environment does lead to increased mutation; you need those mutations to be both advantageous and concentrated to see them retained and expressed in subsequent generations.  (Thus, no giant mutated deer that suddenly evolves and decides to march on Tokyo).

So if you have 3 Deer:

• Deer A lives in a nearby forest, unaffected by Chernobyl 
• Deer B lives in Chernobyl's Red Forest and gains an advantageous mutation
• Deer C lives in Chernobyl's Red Forest and gains a disadvantageous mutation

The breeding of Deer A and C likely results in increased mortality and a reduction of likely subsequent breeding

The breeding of Deer A and B could result in advantaged offspring (and some that are merely 'normal')

The breeding of Deer B and C could get both; with the disadvantaged offspring likely dying early, so over time the disadvantageous mutation disappears

So within the Red Forest you might have a population that has (or will over time) some measure of advantage... but the more often they wander out of the contained space of the Red Forest - the more 'washed out' those advantageous mutations will be in the general deer population.

 

 

 

 

 

 

[kerbiloid]

We should remember that in the Fallout universe this is not just radiation  causing mutations.

They also have FEV.
Mostly in special places like Mariposa Base, but also contaminating the whole biosphere.

https://fallout.fandom.com/wiki/Forced_Evolutionary_Virus

[JoeSchmuckatelli]

38 minutes ago, JoeSchmuckatelli said:

So within the Red Forest you might have a population that has (or will over time) some measure of advantage... but the more often they wander out of the contained space of the Red Forest - the more 'washed out' those advantageous mutations will be in the general deer population.

I just want to add to this: the mere concentration of the possibility of mutation isn't enough.  They have to have some kind of environmental factor that the expressed genes can take advantage of.   Specifically, to be advantageous, there almost has to be something unique within the environment that others (previously) were unable to exploit or that the new ones are less subject to.

Thus, in the Red Forest... what is likely being coded for is resistance to radiation - not something that might be more advantageous in the wider sphere.  Every Red Forest deer that wanders out finds itself in a 'normal' environment and so the expressed genes that made that deer stronger and more capable inside the Red Forest aren't any better in the normal forest.

8 minutes ago, kerbiloid said:

They also have FEV.

FEV - like mutations would have specific coded changes, thus not environmentally driven... which might give you a few individuals (and possibly a breeding group) that could be externally (artificially) maintained... but I suspect that once released into the broader environment the same thing happens.  The mutations are not broadly beneficial and die out fairly quickly (especially if FEV renders the surviving subjects sufficiently different that all offspring that survive are essentially mules).

@Spacescifi touched on some of this stuff months ago: should his 'meddlers' find an environment that normal humans could not survive in, a group might be engineered that was tailormade for that planetary environment... but they'd essentially no longer be human (or capable of breeding back in).

[kerbiloid]

9 minutes ago, JoeSchmuckatelli said:

Red Forest

ru/wiki looks more detailed on this topic

https://ru-m-wikipedia-org.translate.goog/wiki/Рыжий_лес?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=ru

Also, it anyway was halfly killed with fire in 2020.

16 minutes ago, JoeSchmuckatelli said:

FEV - like mutations would have specific coded changes, thus not environmentally driven... which might give you a few individuals (and possibly a breeding group) that could be externally (artificially) maintained... but I suspect that once released into the broader environment the same thing happens.  The mutations are not broadly beneficial and die out fairly quickly (especially if FEV renders the surviving subjects sufficiently different that all offspring that survive are essentially mules).

Imho, FEV likely tries to repair the organism, managing the mutations in the most constructive way.

(More or less like the zombie virus in Andrey Cruz novels, criticized on this forum by the people who unlikely had seen any zombie (in literal, not figurative sense of the word)).

Thus, in Fallout we can see various ugly but workable mutations, and the ghouls,  forced to stay intact.

The radiation is what causes the mutations, the FEV is what makes them healthy.

Irl we have just the former.

[TheSaint]

2 hours ago, JoeSchmuckatelli said:

I cannot tell you how disappointed I am to learn this: I figured that (especially with some of the outlandish proposals) that we had some pretty good ideas waiting in the wings. 

I think at times we tend to lose sight of the fact that science fiction is, well, fiction. Not all of our crazy dreams are going to come true. And incredible technologies are going to come out of nowhere and surprise us. Or bite us in the ass, as the case may be.

[JoeSchmuckatelli]

Just now, TheSaint said:

I think at times we tend to lose sight of the fact that science fiction is, well, fiction. Not all of our crazy dreams are going to come true. And incredible technologies are going to come out of nowhere and surprise us. Or bite us in the ass, as the case may be.

Agree - the problem for me in this - I wasn't looking at directly sci-fi stuff.  Thus the unreasoned hope.