Manufacturing Nukes...In SPACE

[Spacescifi]

 

Let's imagine that Project Orion takes off one day.

According to Kerbiloid, an Orion may have about 48 hours worth of thrust from the maximum amount of bombs carried by the ship.

At some point we both know the vessel is going to run out of nukes.

48 hours of thrust is nothing to underestimate, but more is always better.

So....how feasible is manufacturing nukes in space with all theoretical futuristic tech we can bring to bear?

Like I know a scifi alchemy machine would make it probably too easy, but more theoretical realistic options would involve:

1. Finding some place not Earth with raw nuclear bomb resources....not the moon by the way, since it has thorium for nuclear reactors but scant uranium. Where? What world is a good place to start with a bunch of uranium or sources to make plutonium? 

2. Send a prep Orion ahead to set a up a base, and manufacture nukes in situ there. Yes that's right, an Orion devoted purely to being the nucleus of  a nuke manufacturing outpost for orbiting Orions that come later.

3. Either land orbiter orions to collect bomb fuel, or mag rail launch them into orbit so the orbiters can catch them via nets and shuttles.

 

Challenges: A lot of gear will come straight from Earth with no substitutes. The few things that won't will be what is plentiful at the outpost. Namely ore and minerals, and most important of all, uranium and sources for plutonium.

 

Advantages: Nuke refueling outpost! Yay!

Concerns: Nukes. In space. Operated by nations that sometimes act like...

Spoiler

 

Challenges: Centrifuges and yellow cake in space anyone? That's what's required at the colony world outpost unless I am forgetting something. Water would be nice too.

Your thoughts?

 

 

 

 

 

Edited April 26, 2021 by Spacescifi

[kerbiloid]

https://en.wikipedia.org/wiki/Goldschmidt_classification

U is lithophile and belongs to the column close to Ca and Al.

Crusts, oceans, probably ice.

[Shpaget]

With the idea of producing enough bombs to sustain two pulses per second? Not a chance.

Do some math and calculate how much ore you would need to dig up just to feed the centrifuges. Then take a look at those centrifuges, how immensly huge those facilities are, and how long it takes to enrich uranium. And you want to make ~200 000 bombs per day. Not a chance.

Making a facility on Earth that can produce 200 000 regular hand grenades per day would be an amazing undertaking.

Edited April 26, 2021 by Shpaget

[Spacescifi]

4 minutes ago, Shpaget said:

With the idea of producing enough bombs to sustain two pulses per second? Not a chance.

Do some math and calculate how much ore you would need to dig up just to feed the centrifuges. Then take a look at those centrifuges, how immensly huge those facilities are, and how long it takes to enrich uranium. And you want to make ~200 000 bombs per day. Not a chance.

Making a facility on Earth that can produce 200 000 regular hand grenades per day would be an amazing undertaking.

 

Hmmm....I see.

 

So Orions are a round trip maiden voyage and come home type of vessel...if at all.

Per day? Come now.

Prep time. Give it about four years of manufacturing. Which is peanuts really..then send in the Orion explorer.

 

There is no hurry.

[Shpaget]

The idea falls apart as soon as you consider the logistics, even considering prep time.

Assume ten years of bomb making prep time, and a somewhat less totally impossible production rate of 2 000 bomb per day, which would give us one day of propulsion after 100 days of production. After ten years you would have a stockpile for about 35 days of propulsion.

By my rough calculation, if you find a very good deposit of uranium with about 10% grade ore, you would need about 20 tons of ore to make one bomb. That's about two large dump trucks worth of dirt that you need to transport for each bomb, or 4 000 truckloads per day. That's still more than one per minute. Now, that is raw ore, but there is pretty much exactly the same amount of depleted leftover you need to discard someplace, so another 4 000 truckloads have to leave your facility each day. Sure, if ore processing and enriching is done in the same facility, then the same trucks can offload ore, drive a couple of kilometers within the facility and load the waste material, but that is still a huge volume of material to shift around.

 

[KSK]

There's more to nuclear explosives than uranium. At least there is if you want to make them compact enough to serve as an Orion pulse unit. Take a look at the relevant Wikipedia page - lots of information about nuclear weapon design which will give you some idea of what you need to make them. You can also add 'precision machine tools' to the list and  'advanced electronics'  because the various implosion designs outlined require very accurately shaped parts and highly accurate timers to make sure that the various conventional explosions all happen together.

I think I read somewhere that much of the classified information on nuclear weapon design is to do with the details of those timers.

Building an off-world 'raw ore to finished product' nuke plant is a major undertaking even with sci-fi tech to help out. Shipping some parts in from Earth would make things considerably easier.

1 hour ago, kerbiloid said:

https://en.wikipedia.org/wiki/Goldschmidt_classification

U is lithophile and belongs to the column close to Ca and Al.

Crusts, oceans, probably ice.

For your safety and comfort, incoming pilots are requested not to lithobrake on the lithophile deposits.

[radonek]

AFAIK heavy elements like Uranium tend to concentrate in planetary core during formation period, so that is where I would start. I bet that 16 Psyche holds a significant amount. If I can't get my hands on piece of planetary core (read: metallic asteroid), I would look for planetary body big enough to undergo at least a bit of differentiation process, but small enough to dig deep into. (Ceres? Sedna?  Dunno if suitable candidate actually exists.) Last resort would be scouring small bodies that did not participate in planetary formation at all. These should be relatively richer in heavy elements then planetary crusts, but this would still involve processing huge amount of material. I see this as quite feasible if you have civilization that already process these for other usefuls, but certainly not as small scale ISRU operation.

One other thing that comes to mind is filtering Uranium out of water. Now this would obviously be incredibly inefficient and not break even energy-wise, but if you assume some external energy source, it is only way I can think of that would involve a "machine" and not whole industrial base. Just drop filtering complex into seas of Europe or Enceladus, busy yourself for a few decades (!) and then collect small amount of fissionables (and other useful stuff too). Might be good for something like unmanned interstellar probe.

7 hours ago, Spacescifi said:

how feasible is manufacturing nukes in space with all theoretical futuristic tech we can bring to bear?

Don't you think that going all  futuristic kinda defeats the purpose? Main advantage of Orion was that it could be realistically made with something like sixties tech. With sufficiently  advanced technology, it would make more sense to scoop hydrogen from gas giants for a fusion torch.

[kerbiloid]

1 hour ago, radonek said:

One other thing that comes to mind is filtering Uranium out of water. Now this would obviously be incredibly inefficient and not break even energy-wise,

They do it. Plastic nets are hanging from a floating platform, the U ions react with them and get bound.

Peiodically they replace the dirty nets with clean ones, and put the dirty nets into a pool with solution which destroys the U compounds and releases it to the pool water.

The net gets cleaned and returns to the p.1.

Edited April 26, 2021 by kerbiloid

[radonek]

2 minutes ago, kerbiloid said:

They do it.

Seriously? I mentioned it mostly for the sake of completeness and expected to be laughed off. This just blows my mind. Also the process you describe is neat, if that plastic can be manufactured in situ, it might scale somewhat.

[kerbiloid]

4 hours ago, radonek said:

Seriously? I mentioned it mostly for the sake of completeness and expected to be laughed off. This just blows my mind. Also the process you describe is neat, if that plastic can be manufactured in situ, it might scale somewhat.

https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/?sh=5f93f0ec159a

https://www.machinedesign.com/materials/article/21836993/uranium-extracted-from-seawater

Lithium also, with other kind of nets.

Edited April 26, 2021 by kerbiloid

[KSK]

3 hours ago, kerbiloid said:

They do it. Plastic nets are hanging from a floating platform, the U ions react with them and get bound.

Peiodically they replace the dirty nets with clean ones, and put the dirty nets into a pool with solution which destroys the U compounds and releases it to the pool water.

The net gets cleaned and returns to the p.1.

Wow. I’m with @radonekhere. Do they also use that plastic for soil remediation? Because it sounds like it might be useful for cleaning up heavy metal leachate.

[Spacescifi]

5 hours ago, radonek said:

AFAIK heavy elements like Uranium tend to concentrate in planetary core during formation period, so that is where I would start. I bet that 16 Psyche holds a significant amount. If I can't get my hands on piece of planetary core (read: metallic asteroid), I would look for planetary body big enough to undergo at least a bit of differentiation process, but small enough to dig deep into. (Ceres? Sedna?  Dunno if suitable candidate actually exists.) Last resort would be scouring small bodies that did not participate in planetary formation at all. These should be relatively richer in heavy elements then planetary crusts, but this would still involve processing huge amount of material. I see this as quite feasible if you have civilization that already process these for other usefuls, but certainly not as small scale ISRU operation.

One other thing that comes to mind is filtering Uranium out of water. Now this would obviously be incredibly inefficient and not break even energy-wise, but if you assume some external energy source, it is only way I can think of that would involve a "machine" and not whole industrial base. Just drop filtering complex into seas of Europe or Enceladus, busy yourself for a few decades (!) and then collect small amount of fissionables (and other useful stuff too). Might be good for something like unmanned interstellar probe.

Don't you think that going all  futuristic kinda defeats the purpose? Main advantage of Orion was that it could be realistically made with something like sixties tech. With sufficiently  advanced technology, it would make more sense to scoop hydrogen from gas giants for a fusion torch.

 

I am not sure that going futuristic defeats Orion.

Actually I think it only improves and scales it up.

 

Fusion torch drives, seem like they scale up but would not scale down. And NSWR is the closest we have to that.

That said, I think an Orion can out perform a NSWR for endurance if nothing else.

 

With futuristic versions the more powerful the bomb the more thrust an Orion would gain, whereas internalized rocket engines are limited by how much heat the generate.

Orions can handle their reaction mass heat better and gain higher thrust to.

For futuristic  spaceships Orion wins I think versus any kind of rocket. Because it can utilize more energetic reactions and convert them to thrust.

[kerbiloid]

55 minutes ago, KSK said:

Do they also use that plastic for soil remediation? Because it sounds like it might be useful for cleaning up heavy metal leachate.

Looks that currently they use it to clean the ocean from metals, but as principle is same, I believe they will be extracting them from any pulp.

[sevenperforce]

Total and complete non-starter.

You might as well try to suggest trying to manufacture JP-1 while flying over the Pacific ocean in a 747.

[radonek]

@Spacescifi NSWR also needs fissionables, so it's close to Orion as far as industrial production is concerned.  But might be better if you are after self-sufficiency. AFAIK all you need to replenish NSWR propulsion bus is to mix up  fissionables, water and maybe some moderator additive. Producing Orion charges is much more complicated process as mentioned above. And IIRC it also requires significant amount of tungsten. (Can nonfissionable uranium be used instead?)

45 minutes ago, Spacescifi said:

…the more powerful the bomb the more thrust an Orion would gain…

I don't think it's that easy. Orion drive thrust is limited by pusher plate design. More powerfull charges will likely result in bumpy ride and breakdowns. But it is true that modifications of existing Orion ships to increase thrust would be simple compared to most other propulsion methods. And less need for cooling is definitely a huge advantage.

[MKI]

If you have the manufacturing capabilities to create that much nuclear explosive material in flight, I'd question if an Orion Drive would be the most efficient method of propulsion for such technological investment.

Aren't there other alternatives that are just "more advanced", like fusion/fission drives of some kind? If you want to take on an engineering challenge, I'm not sure if optimizing the Orion Drive is the one you'd pick. If we had to pick a "fictional drive" to focus on making possible I wouldn't pick a "in-flight manufactured Orion Drive". It might be great as a intern solution since its practical, but optimizing it that much doesn't seem that optimal.

 

I'd compare it to trying to optimize a steam powered car, when you could just move onto gas and electrical powered ones. Then again if a simple Orion Drive works well enough... you don't need anything more advanced like inflight manufacturing versions of it.