Radiation Shadows

[joratto]

Given that we'll have procedural radiators and dangerous nuclear radiation in this game, I'd really like to see a system that gives players a reason for angling their radiators and other ship parts (especially crew quarters!) to keep them in the shadow of radiation from certain fission/fusion engines, besides just making them look cool. Irl, neutron embrittlement is a massive risk to delicate radiators and solar panels, and that's why we see those angled radiators so often in hard science fiction.

I've included a link to a picture from Atomic Rockets that illustrates what I mean

http://www.projectrho.com/public_html/rocket/images/radiation/tankShadow02.jpg

and the Atomic Rockets article it comes from

http://www.projectrho.com/public_html/rocket/radiation.php#:~:text=In some propulsion systems%2C such,and which fuel is used.

I'm thinking that a similar-looking sort of toggleable radiation shadow overlay in the VAB would be a really intuitive way to teach about radiation damage.

Would anyone else like to see a similar mechanic in the game, or would it seem too restrictive? Could it even be practically implemented?

 

Edited May 9, 2022 by joratto

[Laxez]

I am sure I saw a topic in this forum about the VAB HUD that you could see, but I can't find it... anyway, I'm sure I saw a button next to those that indicated the center of mass, the direction of the vector and the center of the thrust, followed precisely by this button with the symbol of radioactivity which I think is exactly what you would like

[Pthigrivi]

Yeah there is an indicator for radiation in the VAB so its very likely to be a design factor. Most folks have been envisioning it having an effect on kerbals but thats a good point about radiators. Its generally considered that random failures are a no-no, but it could be abstracted by drastically reducing the efficacy of radiators or other components that aren't shielded. 

[joratto]

Quote

I'm sure I saw a button next to those that indicated the center of mass, the direction of the vector and the center of the thrust, followed precisely by this button with the symbol of radioactivity

I saw!! Very exciting and I hope they'll model more than just e.g. the distance from the center of radiation and the effect that has on kerbals alone.

Edited May 9, 2022 by joratto

[Laxez]

41 minutes ago, Pthigrivi said:

Yeah there is an indicator for radiation in the VAB so its very likely to be a design factor. Most folks have been envisioning it having an effect on kerbals but thats a good point about radiators. Its generally considered that random failures are a no-no, but it could be abstracted by drastically reducing the efficacy of radiators or other components that aren't shielded. 

the "easy way" would be to do as in ksp1 when you are re-entering the atmosphere and you lose the heat shield and everything starts to explode. but maybe they have foreseen something else, personally I can not think of anything other than the death of the Kerbal, with its space wreck wandering through space (it would be very cool then to go and take it back, in the Alien way), I have no other ideas of what can happen in ksp2 if the anti-radiation shield breaks. in reality, people would begin to die of radioactivity for sure.

[joratto]

11 minutes ago, Laxez said:

I can not think of anything other than the death of the Kerbal, with its space wreck wandering through space (it would be very cool then to go and take it back, in the Alien way), I have no other ideas of what can happen in ksp2 if the anti-radiation shield breaks. in reality, people would begin to die of radioactivity for sure.

In addition to the risk to kerbal DNA, radiation can also damage delicate electronics including radiators. Even solid metal hulls can fracture over time because of neutron embrittlement! As @Pthigrivi said, radiation damage to unshielded ship parts could manifest as reduced efficiency, and embrittlement could simply make your ship more vulnerable to heat/collisions.

[SciMan]

So, all this is nice and all, but you'll need the thing that creates the shadow in the first place.

Namely, we'll need a new kind of "shield" part. Radiation shielding, to be specific.

Probably 2 kinds.

The first one is "General" or omnidirectional radiation shielding that you might be able to toggle or use a slider to set the thickness of as an option for say a habitation module (with the payment of a mass penalty). This is good for things like colony parts, and "storm cellar" type habitation module parts. This could be represented simply as an accumulation of something like water or planetary matter (aka regolith) around a habitation module.
For regolith, the advantage is that you can collect it locally, the disadvantage is that you don't have it until you DO collect it.
For water, some forms of electrical thruster can make use of water as reaction mass with rather good performance (microwave electro-thermal thrusters specifically), or it can be used as a life support consumable (assuming that if we get some form of life support it uses consumables in the first place and isn't just an always closed-loop system that therefore doesn't require the tracking of any resources), or both. So with water, you can be very efficient with your shielding mass by getting double or even triple use out of it. Water is also another thing which is relatively easy to source from the surface of a planet or moon, assuming it has pretty much any kind of atmosphere or craters that stay permanently shadowed.

 

And then there's the one that for certain needs it's own kind of part (not just one part, unless it's massively procedural). The "Radiation Shadow Shield".
Since I find the shadow shield part more interesting, I'm going to focus on it.

The basic idea of a shadow shield is that it significantly attenuates the radiation from a given source, but only over a relatively narrow range of angles. The reason it doesn't cover more angle is because mass is at a premium and the typical materials used for a radiation shadow shield are quite dense and required in significant quantities.
The typical material of a radiation shadow shield is pure Tungsten, as it is highly effective at attenuating Neutron and Gamma ray radiation (which are the most common and most damaging forms of radiation given off by a typical nuclear reaction created by humans). Energetic Proton radiation (aka GCR radiation) is better handled by materials like Water or Polyethylene plastic that contain large amounts of Hydrogen atoms, and that's covered by the "general radiation shielding" category previously discussed.

Now you might not need much thickness of tungsten, say 10cm of it to cut the radiation down by a factor of at least 8 (I forget the specific numbers), but there's a compromise to be made between the length (and therefore mass) of the truss that the reactor (and potentially any engines, if the two are not one and the same) is/are mounted on versus the thickness and diameter of your shadow shield.
The longer the truss, the thinner (and smaller diameter) you can make your shadow shield, but there's a point where your truss mass starts to out-weigh the mass of the shadow shield, so there's very much a "point of minimum mass expenditure for a given tolerable radiation flux" to be calculated here, like in most things involving space travel.

And additionally, if not given any other options (such as capturing an asteroid or intelligent placement of the stores of fusion-fuel ices) for radiation shielding on interstellar or extremely fast interplanetary (torch-ship) journeys, you'll need ANOTHER shadow shield on the front of the vessel to protect the crew and vessel from the effects of relativistic protons (which are only relativistic because the craft is traveling at relativistic speeds thru the interstellar medium).

To include the radiation shadow shield in the nuclear powered engines themselves is to me a design oversight, as the freedom to design to your own constraints is removed, and replaced with the fact that certain engines will need certain lengths of truss to be safe, and you'll only be able to fit so much behind them given that truss length.
That seems boring to me, so I would prefer if it was avoided.

[Pthigrivi]

Just as a note in the most recent interstellar travel vid the vessels they show do seem to have a variety of radiation shields both at the front of the vessel and separating engines from critical parts of the vessel. Some even have multiple shields as if there's a max radiation limit for things like radiators and lower limit for crew necessitating a secondary shield. It'll be interesting to see how this mechanic plays out. As far as the effect on kerbals themselves I think a ship full of dead kerbals is too grim and punishing. Id rather see things like LS and habitation and radiation folded into an overall health or happiness rating that would effect science returns, harvesting and processing resources, population growth, etc. 

Edited May 9, 2022 by Pthigrivi

[joratto]

11 hours ago, SciMan said:

So, all this is nice and all, but you'll need the thing that creates the shadow in the first place.

Namely, we'll need a new kind of "shield" part. Radiation shielding, to be specific.

Probably 2 kinds.

The first one is "General" or omnidirectional radiation shielding that you might be able to toggle or use a slider to set the thickness of as an option for say a habitation module (with the payment of a mass penalty). This is good for things like colony parts, and "storm cellar" type habitation module parts. This could be represented simply as an accumulation of something like water or planetary matter (aka regolith) around a habitation module.
For regolith, the advantage is that you can collect it locally, the disadvantage is that you don't have it until you DO collect it.
For water, some forms of electrical thruster can make use of water as reaction mass with rather good performance (microwave electro-thermal thrusters specifically), or it can be used as a life support consumable (assuming that if we get some form of life support it uses consumables in the first place and isn't just an always closed-loop system that therefore doesn't require the tracking of any resources), or both. So with water, you can be very efficient with your shielding mass by getting double or even triple use out of it. Water is also another thing which is relatively easy to source from the surface of a planet or moon, assuming it has pretty much any kind of atmosphere or craters that stay permanently shadowed.

 

And then there's the one that for certain needs it's own kind of part (not just one part, unless it's massively procedural). The "Radiation Shadow Shield".
Since I find the shadow shield part more interesting, I'm going to focus on it.

The basic idea of a shadow shield is that it significantly attenuates the radiation from a given source, but only over a relatively narrow range of angles. The reason it doesn't cover more angle is because mass is at a premium and the typical materials used for a radiation shadow shield are quite dense and required in significant quantities.
The typical material of a radiation shadow shield is pure Tungsten, as it is highly effective at attenuating Neutron and Gamma ray radiation (which are the most common and most damaging forms of radiation given off by a typical nuclear reaction created by humans). Energetic Proton radiation (aka GCR radiation) is better handled by materials like Water or Polyethylene plastic that contain large amounts of Hydrogen atoms, and that's covered by the "general radiation shielding" category previously discussed.

Now you might not need much thickness of tungsten, say 10cm of it to cut the radiation down by a factor of at least 8 (I forget the specific numbers), but there's a compromise to be made between the length (and therefore mass) of the truss that the reactor (and potentially any engines, if the two are not one and the same) is/are mounted on versus the thickness and diameter of your shadow shield.
The longer the truss, the thinner (and smaller diameter) you can make your shadow shield, but there's a point where your truss mass starts to out-weigh the mass of the shadow shield, so there's very much a "point of minimum mass expenditure for a given tolerable radiation flux" to be calculated here, like in most things involving space travel.

And additionally, if not given any other options (such as capturing an asteroid or intelligent placement of the stores of fusion-fuel ices) for radiation shielding on interstellar or extremely fast interplanetary (torch-ship) journeys, you'll need ANOTHER shadow shield on the front of the vessel to protect the crew and vessel from the effects of relativistic protons (which are only relativistic because the craft is traveling at relativistic speeds thru the interstellar medium).

To include the radiation shadow shield in the nuclear powered engines themselves is to me a design oversight, as the freedom to design to your own constraints is removed, and replaced with the fact that certain engines will need certain lengths of truss to be safe, and you'll only be able to fit so much behind them given that truss length.
That seems boring to me, so I would prefer if it was avoided.

I’d love to be able to mine regolith and use it to fill “omnidirectional” shielding bags on my surface bases. You could do it with unmanned drones ahead of the arrival of your fragile Kerbal residents.

As for shadow shields, I could see it working with several standard sizes like the heat shields we already have, though procedural would be ideal! Procedural trusses would be even better. No matter how you introduce it, I 100% do not want the shields to be built in to the reactors/engines. Having custom shields and their resultant shadows could introduce a really fun constraint vaguely analogous to the problem of fitting parts inside a fairing.

That said, I’ll add that I think I remember Nate Simpson saying there would be no relativistic interstellar particles or other obstacles you’d need to shield from precisely because they wanted to avoid forcing players to make completely shielded “pill ships”.

10 hours ago, Pthigrivi said:

Just as a note in the most recent interstellar travel vid the vessels they show do seem to have a variety of radiation shields both at the front of the vessel and separating engines from critical parts of the vessel. Some even have multiple shields as if there's a max radiation limit for things like radiators and lower limit for crew necessitating a secondary shield. It'll be interesting to see how this mechanic plays out. As far as the effect on kerbals themselves I think a ship full of dead kerbals is too grim and punishing. Id rather see things like LS and habitation and radiation folded into an overall health or happiness rating that would effect science returns, harvesting and processing resources, population growth, etc. 

Good point! I expect different parts of the ship to have different shielding demands, so you could potentially fine-tune your protection with smaller shields rather than just one big saucer. I wonder if there would be benefits to stacking multiple shields in a Whipple arrangement with space in-between.

Edited May 10, 2022 by joratto

[Catto]

I used to just clip an inflated heat shield inline between the nuclear and the habitat part, so it looks like a shield. I kinda still do.

[SciMan]

KSP Interstellar Extended has a part purpose-built for the purpose of being a radiation shadow shield or interstellar debris shield, but that mod on its own does not require you to use them, instead for that you need Kerbalism (I think), but there are several other reasons that I avoid that mod like the plague (mostly compatibility issues WRT other mods and the fact that it's really meant to be a thing for RSS-RO and not "normal" KSP, and the fact that it does a little bit of a lot of things and therefore for my tastes changes the game too much compared to the KSP I know, sort of like playing GregTech (a total conversion mod for Minecraft) after being used to a more normal Minecraft "high technology" mod pack (using for example IndustrialCraft 2 as well as many others)).

Put another way, if the mechanics aren't in vanilla KSP 2, I don't particularly expect the mods for them to hit a good balance between "realism" and "gameplay". The mods we do tend to get, fall heavily on the "realism" side of things. The problem is that instead of true "realism", what we get is "lots and lots of micromanagement". I don't particularly like ACTIVE micromanagement in video games. If I have to design something in a very specific way, that's fine, but I should be able to design it (once, if the first design is workabe), and launch it, send it on its way, and then FORGET ABOUT ITS EXISTENCE ENTIRELY until an alarm clock thing reminds me that it's nearing its destination.
I shouldn't have to visit it every month or more often to manage something. The crew of the ship should be able to do that AUTOMATICALLY.

Automate Automate Automate! The less I have to "play the game" of "clicking on eleventy bajillion part action windows to do something that IRL would have an automated management system controlling it", the better.
I'm not sure if it's KSP game limitations or just lack of imagination or effort on the part of the mod makers (don't get me wrong, what they've done is amazing, my complaints are not saying these are "bad mods" by any means), but it seems that that's exactly what you have to do to get anything done with these colonization and life support mods 99% of the time, and that's not exploring space to me, that's "playing a management simulator" which is exactly the reason that I do NOT play KSP 1 career mode (much prefer Science mode, still has some progression but you're able to do what YOU want not what you "need to do to make money", don't confuse the two, they sometimes align but not often for me, I hate tourism contracts for example yet they're the most optimal way to make money in KSP 1 Career mode).

[joratto]

41 minutes ago, SciMan said:

KSP Interstellar Extended has a part purpose-built for the purpose of being a radiation shadow shield or interstellar debris shield, but that mod on its own does not require you to use them, instead for that you need Kerbalism (I think), but there are several other reasons that I avoid that mod like the plague (mostly compatibility issues WRT other mods and the fact that it's really meant to be a thing for RSS-RO and not "normal" KSP, and the fact that it does a little bit of a lot of things and therefore for my tastes changes the game too much compared to the KSP I know, sort of like playing GregTech (a total conversion mod for Minecraft) after being used to a more normal Minecraft "high technology" mod pack (using for example IndustrialCraft 2 as well as many others)).

Put another way, if the mechanics aren't in vanilla KSP 2, I don't particularly expect the mods for them to hit a good balance between "realism" and "gameplay". The mods we do tend to get, fall heavily on the "realism" side of things. The problem is that instead of true "realism", what we get is "lots and lots of micromanagement". I don't particularly like ACTIVE micromanagement in video games. If I have to design something in a very specific way, that's fine, but I should be able to design it (once, if the first design is workabe), and launch it, send it on its way, and then FORGET ABOUT ITS EXISTENCE ENTIRELY until an alarm clock thing reminds me that it's nearing its destination.
I shouldn't have to visit it every month or more often to manage something. The crew of the ship should be able to do that AUTOMATICALLY.

Automate Automate Automate! The less I have to "play the game" of "clicking on eleventy bajillion part action windows to do something that IRL would have an automated management system controlling it", the better.
I'm not sure if it's KSP game limitations or just lack of imagination or effort on the part of the mod makers (don't get me wrong, what they've done is amazing, my complaints are not saying these are "bad mods" by any means), but it seems that that's exactly what you have to do to get anything done with these colonization and life support mods 99% of the time, and that's not exploring space to me, that's "playing a management simulator" which is exactly the reason that I do NOT play KSP 1 career mode (much prefer Science mode, still has some progression but you're able to do what YOU want not what you "need to do to make money", don't confuse the two, they sometimes align but not often for me, I hate tourism contracts for example yet they're the most optimal way to make money in KSP 1 Career mode).

And this is why instead of just “leaving it to the mods” for every new suggested feature, it is often a good idea to leave game design to the professional game designers.

[mattinoz]

6 hours ago, joratto said:

And this is why instead of just “leaving it to the mods” for every new suggested feature, it is often a good idea to leave game design to the professional game designers.

It also make the game more modable if there is a base game system that makes a structure that is consistent. Gives the mods something to hang one without making a system from scratch. You don't need 6 competing life support systems with a vast array of mods compatible with half of them if there is a solid base.

They don't need to go overboard either, concentrate on good game play then if a modder wants to make a process around making x-factor more realistic they can.