parts [1.12.x] 'Project Orion' Nuclear Pulse Engine

[damerell]

3 hours ago, magnemoe said:

20.000 bombs weight 100.000 kg, making each bomb weight 5 kg, this is very light and to my surprise the craft only got one ton lighter.

One of the respects in which our understanding of Project Orion's real-world feasibility is limited is that we don't know how small one can make a hydrogen bomb. That, and techniques for making very small bombs, is kept extremely secret; for obvious reasons, very small bombs would be of much more use to many malicious actors than very large ones.

This is unfortunate from our point of view because the size of the smallest bomb determines the mass of the smallest viable Orion-powered craft - below that mass the peak acceleration from one detonation would be hazardous to the ship and crew [1]. This is why Dyson et al planned to send a mission the size of a hotel to the outer planets; large bombs mean large ships.

I'm not convinced by your calculation above, although I may have made an error myself. 2006 m/s=v * g * ln(195.03/194) seems to be the rocket equation with an additional spurious term "g". Omitting that we conclude that v (exhaust velocity) is 379 km/s. Specific impulse is a silly proxy for exhaust velocity but it would hence be a bit over 38ks. 12ks is the highest specific impulse suggested by Project Orion in the late 50s but later theoretical work has suggested figures around 40ks.

I strongly recommend "Project Orion: The Atomic Spaceship 1957-1965", George Dyson, 2002. ISBN 0-140-27732-3.

[1] Or you could harness the detonation less efficienctly, but then - a phrase almost never used in spacecraft design - you might as well just have a heavier spacecraft.

[magnemoe]

1 hour ago, damerell said:

One of the respects in which our understanding of Project Orion's real-world feasibility is limited is that we don't know how small one can make a hydrogen bomb. That, and techniques for making very small bombs, is kept extremely secret; for obvious reasons, very small bombs would be of much more use to many malicious actors than very large ones.

This is unfortunate from our point of view because the size of the smallest bomb determines the mass of the smallest viable Orion-powered craft - below that mass the peak acceleration from one detonation would be hazardous to the ship and crew [1]. This is why Dyson et al planned to send a mission the size of a hotel to the outer planets; large bombs mean large ships.

I'm not convinced by your calculation above, although I may have made an error myself. 2006 m/s=v * g * ln(195.03/194) seems to be the rocket equation with an additional spurious term "g". Omitting that we conclude that v (exhaust velocity) is 379 km/s. Specific impulse is a silly proxy for exhaust velocity but it would hence be a bit over 38ks. 12ks is the highest specific impulse suggested by Project Orion in the late 50s but later theoretical work has suggested figures around 40ks.

I strongly recommend "Project Orion: The Atomic Spaceship 1957-1965", George Dyson, 2002. ISBN 0-140-27732-3.

[1] Or you could harness the detonation less efficienctly, but then - a phrase almost never used in spacecraft design - you might as well just have a heavier spacecraft.

Problem with hydrogen bombs is that they require an fission trigger, so you need an critical mass of plutonium or weapon grade uranium, lightest bombs was still around 50 kg. An orion charge would also require an reaction mass, tungsten or similar who hit the push plate.

However back then they worked with project orion it was believed that they should be able to build fusion bombs without the fission trigger, this would have multiple benefits like smaller bombs, very little fallout and probably also fusion power, this was not solvable.
Orion is a case where increased size increased efficiency heavier ship with larger push plate let you use larger and more efficient bombs increasing efficiency. 

Some current engine ideas is using pulsed fusion without bombs. You use magnetic and electrical fields to compress the fusion material, you get fusion, its not break even but you don't need it you need plasma moving fast out of the engine, you can get electricity far easier than high isp


 

 

[damerell]

13 hours ago, magnemoe said:

Problem with hydrogen bombs is that they require an fission trigger, so you need an critical mass of plutonium or weapon grade uranium, lightest bombs was still around 50 kg. An orion charge would also require an reaction mass, tungsten or similar who hit the push plate.

However back then they worked with project orion it was believed that they should be able to build fusion bombs without the fission trigger, this would have multiple benefits like smaller bombs, very little fallout and probably also fusion power, this was not solvable.

You've missed the point. You don't know how small a fusion bomb can be made, or if this problem was solvable. It is a closely guarded secret. (The lightest fission mass is considerably less than 50kg; the lowest plutonium mass we're allowed to know about is "less than a kilogram, considerably less" (Ted Taylor, ex-Los Alamos, in 1986)).

Given the way kerbals' engineering is superlative and everything is smaller in their universe, it doesn't seem unreasonable to suppose they have cracked this particular nut.

[magnemoe]

1 hour ago, damerell said:

You've missed the point. You don't know how small a fusion bomb can be made, or if this problem was solvable. It is a closely guarded secret. (The lightest fission mass is considerably less than 50kg; the lowest plutonium mass we're allowed to know about is "less than a kilogram, considerably less" (Ted Taylor, ex-Los Alamos, in 1986)).

Given the way kerbals' engineering is superlative and everything is smaller in their universe, it doesn't seem unreasonable to suppose they have cracked this particular nut.

For military use its of limited value to get smaller nuclear bombs, yes it would be nice but not critical, you had the 155 mm artillery shell and the demolition charge who was bulkier but lighter think it was below 50 kg as you say. Both was however far below a kiloton in effect, you would get much of the same effect out of an heavy bomber with normal bombs. 

Anyway KSP is not real life, ships is far lighter so charge strength and weight has to be scaled down. At the same time burn time also has to be fairly short.
Now one thing I could wish was to have multiple charge types in an magazine. 

[Constan7ine]

I just realized what this mod is. It's completely absurd. 

I love it.

[percyPrune]

Hi RD,

First: Brilliant mod! I never go Kerballed interplanetary without it, even if I have to do a lot of Mun tourist contracts to afford the initial cost!

However, I don't seem to be getting any thrust from Orion or Medusa in KSP1.2 (worked OK in 1.05)

I have tried installing just your Orion pack at https://github.com/BobPalmer/NuclearRockets or USI constellation pack (including FS &MM) at https://github.com/BobPalmer/USI_Constellation/releases/ into clean 1.2x32 and 1.2x64 saves but I get no joy with any combination.

I get the animations and sounds OK, bombs are being consumed and the movement of the Orion pusher will pogo the ship off the launchpad (destroying the pad in the process) but even avoiding atmo. effects by launching into LKO by conventional means makes no difference to the thrust when Orion is staged. The readout stays at "0.1" even at 100% throttle with all resources met 100%.

If I hack the thrust in the .cfg file from 0.1 to around 10000 it starts working but then the ablative oil runs out within a few dozen pulses.

Have I got something missing/ corrupted?

Percy

[magnemoe]

1 hour ago, percyPrune said:

Hi RD,

First: Brilliant mod! I never go Kerballed interplanetary without it, even if I have to do a lot of Mun tourist contracts to afford the initial cost!

However, I don't seem to be getting any thrust from Orion or Medusa in KSP1.2 (worked OK in 1.05)

I have tried installing just your Orion pack at https://github.com/BobPalmer/NuclearRockets or USI constellation pack (including FS &MM) at https://github.com/BobPalmer/USI_Constellation/releases/ into clean 1.2x32 and 1.2x64 saves but I get no joy with any combination.

I get the animations and sounds OK, bombs are being consumed and the movement of the Orion pusher will pogo the ship off the launchpad (destroying the pad in the process) but even avoiding atmo. effects by launching into LKO by conventional means makes no difference to the thrust when Orion is staged. The readout stays at "0.1" even at 100% throttle with all resources met 100%.

If I hack the thrust in the .cfg file from 0.1 to around 10000 it starts working but then the ablative oil runs out within a few dozen pulses.

Have I got something missing/ corrupted?

Percy

Atmospheric isp is nerfed hard as LV-N, you want it up to 20 km before starting it. The medusa never worked inside atmospheres at all. 

Ok so it don't work outside of atmosphere either. 
My quess is an mod conflict, might also be an old modulemanager. 
Try an copy of the game with just the orion mod, then add mods until things break
 

[percyPrune]

Quote

Try an copy of the game with just the orion mod

Done exactly that using only what was in RoverDude's packs

2 separate clean installs of 1.2 and 1.2 64bit.

No joy.

pP

[ExplodingWaffle101]

As some others say: this mod is broken.

It seems like there is a thrust number on the engines, but it doesnt seem to be the one outputting to physics and co: that looks to be 0.1kN.

[RoverDude]

On 10/20/2016 at 10:01 AM, percyPrune said:

Hi RD,

First: Brilliant mod! I never go Kerballed interplanetary without it, even if I have to do a lot of Mun tourist contracts to afford the initial cost!

However, I don't seem to be getting any thrust from Orion or Medusa in KSP1.2 (worked OK in 1.05)

I have tried installing just your Orion pack at https://github.com/BobPalmer/NuclearRockets or USI constellation pack (including FS &MM) at https://github.com/BobPalmer/USI_Constellation/releases/ into clean 1.2x32 and 1.2x64 saves but I get no joy with any combination.

I get the animations and sounds OK, bombs are being consumed and the movement of the Orion pusher will pogo the ship off the launchpad (destroying the pad in the process) but even avoiding atmo. effects by launching into LKO by conventional means makes no difference to the thrust when Orion is staged. The readout stays at "0.1" even at 100% throttle with all resources met 100%.

If I hack the thrust in the .cfg file from 0.1 to around 10000 it starts working but then the ablative oil runs out within a few dozen pulses.

Have I got something missing/ corrupted?

Percy

Did you activate in orbit?  It is nerfed in atmosphere.

On 10/20/2016 at 11:28 AM, percyPrune said:

Done exactly that using only what was in RoverDude's packs

2 separate clean installs of 1.2 and 1.2 64bit.

No joy.

pP

See prior question.

4 hours ago, ExplodingWaffle101 said:

As some others say: this mod is broken.

It seems like there is a thrust number on the engines, but it doesnt seem to be the one outputting to physics and co: that looks to be 0.1kN.

See above.

[percyPrune]

Per my oringinal post:

Quote

even avoiding atmo. effects by launching into LKO by conventional means makes no difference to the thrust when Orion is staged.

Basically, I strapped a decoupler, plus half a dozen Kerbodyne tanks and Mammoth engines to the orion, blasted to 100k, decoupled and fired the orion through the staging.

Result: Animation, flashes, noise, no thrust, no chage in dV, no change in Ap. I have checked that the NPUs in the tank match the engine and tried it with separate launches of each size of NPU

All in a clean KSP 1.2 install.

The GameData folder contains:

(folder) 000_USITools

(folder) Firespitter (As supplied with orion. Contains FS plugins (in subfolder) version 7,4,1)

(folder) Squad

(fiolder) UmbraSpaceIndustries (includes Orion version 0.3.1.0 in subfolder)

ModuleManager 2.7.1.dll + MM created files

 

Edited October 23, 2016 by percyPrune

[damerell]

What happens if you manually activate the engine by right-clicking it?

[RoverDude]

You added charges correct?  Of the right size?  And selected said charges on your engine?  And you are on the latest version?

 

[percyPrune]

Yes, added charges.

Yes, and tried separate launches of each size to see if only one size was affected. No joy with any size*

Yes, Selected same charge size for engine

Version 0.3.1.0 for KSP 1.2.0,  as listed in the file accompanying the Orion folder I downloaded from your link. (see my previous post)

Manually clicking the engine starts and stops the animations but still no thrust.

(Edit)

Just noticed that you released 0.3.2.0 yesterday! Will try that and report back.

[Mace from Space]

26 minutes ago, percyPrune said:

Yes, added charges.

Yes, and tried separate launches of each size to see if only one size was affected. No joy with any size*

Yes, Selected same charge size for engine

Version 0.3.1.0 for KSP 1.2.0,  as listed in the file accompanying the Orion folder I downloaded from your link. (see my previous post)

Manually clicking the engine starts and stops the animations but still no thrust.

(Edit)

Just noticed that you released 0.3.2.0 yesterday! Will try that and report back.

Exactly the same behaviour for me. Tested everything coming to my mind. I even sent it out to the suns soi. Tried both engines with every cartridge size available. With 0.3.2.0 coming with the Constellation release i even dont get animations, just sound.

[damerell]

Is the fuel magazine adjacent to the engine? I ask because I have had some vexing issues with fuel feed on Orion (with craft where I would normally expect fuel feed to be possible), which I've never been able to pin down well enough to make a reproducable bug report. So, something to try (if it wasn't that way already) is to put them together.

[percyPrune]

Yes, the magazine is directly attached.

Pic of my test vessel:

In the pic I have just decoupled the chemical launcher and staged Orion. The booster should be destroyed by the first push but no explosion

Tried version 0.3.2.0 with the same result but, unlike mace from space, I get the animations, just still no thrust.

Edited October 24, 2016 by percyPrune

[Odonian]

I was having trouble with the most recent versions of Orion, too, but I managed to get it working again by installing the 2016.10.15.1 Constellation pack.

[percyPrune]

Quote

I managed to get it working again by installing the 2016.10.15.1 Constellation pack.

Thank you Odonian!

Don't know how, don't know why, but it works.

Installed:

USI tools, Community CategoryKit, CommunityResourcePack & Firespitter from USI_2016.10.15.1

Plus:UmbraSpaceIndustries folder containing Orion vers. 0.3.1.0 from USI_2016.10.16.02.

Now got some serious shipbuilding to do

 

[Bill Phil]

Nerfed in atmo? Isn't Orion even better in atmo for the same reason jet engines are? (we're not taking into account the reaction mass of the air when we use effective exhaust velocity). This gives more mass for the propellant, which then gives you more impulse (at the expense of actual velocity). More impulse divided by the same mass of the bomb unit gives a higher specific impulse. But I get that it's a gameplay decision, and ultimately not up to me. Of course KSP isn't going to be that realistic, let alone a mod for KSP. I love this mod to death, btw. Ol' boom boom!

Edited October 28, 2016 by Bill Phil

[Red30000]

So just out of curiosity this is gonna get updated so it works without constellation right? I'm only curious because Constellation has WAY more stuff than I want. (heck I usually pull the reactors and Kontainers folders out because I don't want them) So is it going to work on it's own again or am I going to need to aggressively prune constellation instead?

[Jorbio]

hi RoverDude, 

Your mod Orion_0.3.2.0 dont work for me   in KSP 1.2.1.1604 (WindowsPlayer x64)
I tried with no other mod except  HyperEdit [v1.5.3]
My vx was simply : Mk1 cmd pod, Orion pulse unit magazine, Orion Pulse engine or Medusa
I Start a new game, sandbox mode, and test in space
My GameData : Squad, 000_USITools, Firespitter,UmbraSpaceIndustries

PS : I tried the same test with Orion_0.2.4.0 in my old Ksp version (KSP 1.1.31289 (x64))  and its work fine.
Hope its can help u.

[Red30000]

so uh this mod is still gonna update to something working eventually right?

Edited November 18, 2016 by Red30000

[RoverDude]

Yup.

[Red30000]

great to know i'll stop bothering you and let you back to work thanks for answering my question.

Edited November 21, 2016 by Red30000