nyrath

NASA’s Jet Propulsion Lab is obsessed with a certain game, and I bet you can guess what it is. http://www.penny-arcade.com/report/article/nasas-jet-propulsion-lab-is-obsessed-with-a-certain-game-and-i-bet-you-can- Apparently quite a few people at NASA's Jet Propulsion Laboratory are rabid Kerbal fans.

Very interesting! IIRC the latest scientific thinking is that elements like uranium and thorium will be mostly found in our solar system from the Asteroid belt inward to Mercury, but not in the outer solar system. The only fly in the ointment is that I have so many "fuels", each bomb type has a different mass and thrust. I'd have to make some kind of factory to convert blutonium into magazines.

Yes, it is on my priority list. That would dramatically open up the Kerbal solar system for industrialization. And maybe in the future somebody else could make a "blutonium" mod much like the "kethane" mod, to manufacture orion "fuel" bombs.

More than that. A 1960's study showed that a medium sized Orion had enough delta V to send 1,300 metric tons of payload to the Saturnian moon Enceladus and back! http://www.projectrho.com/public_html/rocket/enginelist.php#id--Pulse--Orion http://www.projectrho.com/public_html/rocket/sealofapproval.php#id--Computer_Simulation--Kerbal_Space_Program--Orion_nuclear_pulse But even though I've studied the the Orion drive extensively, I was shocked at how much thrust and delta V this monster had. Of course I'm not quite sure how accurately I've modeled the performance, but I think I have it pretty closely scaled to the other propulsion systems in KSP. I have had some insights into Orion from just playing with this mod (like it turns with all the agility of a pregnant hippo). Which again demonstrates why KSP is educational like no other game. But you have to keep in mind that in KSP, the Kerbals did not sign a nuclear test ban treaty in 1963.

Ah, yes, people have already been speculating about that. It would be tricky will all those hangar bays. You'd have to go shopping in the Kerbal Spaceport for appropriate weapons.

Great Galloping Galaxies!! And we all thought Project Pluto was bad... I had no idea of the amount of fiendish ingenuity contained in the KSP community. I feel like I've created a monster... Sorry you had a problem, relieved it was not also my problem.

Boy, that is odd. I have no idea what is causing that. I'll play around. You could probably make that yourself. Duplicate one of the bomb folders and re-name it. Edit its part.cfg file: change name= whatever to something new. also change the title and description. change bombImpulse to bombImpulse = 0.0 change destroyZone to the destruction radius in meters that you desire. change destroyMass upwards if need be. Roche has a mass of about 500

Holy Oberth Effect! That's just so wrong. But just so Kerbal. That's one for the record books.

As an experiment, I took your suggestion and tried making the while thing lighter. Unfortunately it did not seem to change anything. And it would mean I would have to reduce the power of the magazines, or one 400 MN charge could send you to Duna. It also did not fix the interpenetrating parts problem, which is interesting. That suggests that something else is the problem. Maybe something strange in the mesh. Ah, that would be good news for me if something else was causing the problem!

ProjectXMark1, I like how you think. Well, that sounds ominous. Let me take another look at the code. Sounds suspiciously like I'm shifting the magazine mass back and forth every couple of frames or something. I'll get back to you. later... No, that wasn't it, I don't think. Maybe related, maybe not. In one of my saved games I have two Orions in orbit. When Orion 1 has its SAS turned on with the "T" key, everything is fine. With Orion 2 however, when I turn on SAS, the yaw-pitch-roll indicators in the lower left jitter. Probably mass related. Still later... Markarian421, could I please have a copy of your persistence file?

Yes, that's the same problem. Thanks for the testing, you've given me more clues. It also seems to be influence by how many tons worth of magazines you have. I'm working on it.

Indeed I do, sir. But thank you for pointing out possible trouble spots. So many of these pitfalls are easy to miss. When I import a mesh from Blender into Unity 3D, one of the things on my checklist is to select each component object and check the "Convex" checkbox in the collider section. I too have had no problem with monopropellant tanks and RCS blocks. But those items attach to the surface of the engine. Scoundrel's exploding ships have parts that actually interpenetrate the engine. In the picture, the conical features are nose cones stuck to the bottom of the magazines. Excellent! I got the impression he was waiting until the mod left alpha and was entered into the spaceport. You might want to pass to him the link to my trials and tribulations http://www.projectrho.com/public_html/rocket/sealofapproval.php#id--Computer_Simulation--Kerbal_Space_Program--Orion_nuclear_pulse

Excellent! So you can land an Orion. Hmmmmmm, that's interesting. Scoundrel and SufficientAnonymity tried creating an Orion where some of the parts interpenetrated into the body of the engine. They would explode on the launch pad the instant the physics turned on. However, it appears that your radial engines interpenetrate. Do they?

I have you listed as "first test pilot of Project Orion"

Thanks! Before I started this I noted that there were zero Orion mods in the spaceport, and about 4 mod attempts that failed halfway through. This told me that the players wanted an Orion, but it was freaking hard to do. Wow! I didn't know that was possible! Amazing! Yes, that is on my list of things to do. It is difficult since the number of different bomb types is determined at run-time. Which means if somebody makes a vessel using bomb feed action groups, launches it, quits game, uninstalls that bomb type, the action group links will be different. I'll see what I can do. :0.0: Great Tsiolkovsky's Ghost! yes, apparently when you apply anything with the symmetry tool, they are all sort of reflections of the same part. I'll add that to my bug list.

The wet workshop mod is a brilliant concept, and I look forwards to it. More to the point, it just goes to hammer home why I think KSP is one of the most awesome games ever. In real life, the engineers at NASA were faced with the tyranny of the rocket equation, and came up with the wet workshop concept in an attempt to make the mass devoted to the fuel tank do double duty as a space station component. KSP models this situation so accurately that players are faced with the same problems, and solutions which work in the real world will work in the game as well. I will also note how many players have independently invented the concept of orbital propellant depots, since the players are faced with the same problems faced by real aerospace engineers. Majiir may or may not have been inspired by NASA work on in-situ resource utilization when the Kethane mod was invented, but once again the same situation creates similar solutions. And that is why Kerbal Space Program is awesome.

excellent picture Canopus! Somebody suggested that I talk about my Orion mod on my website http://www.projectrho.com/public_html/rocket/sealofapproval.php#id--Computer_Simulation--Kerbal_Space_Program--Orion_nuclear_pulse

Thanks, Scoundrel! The test vehicles enthusiastically explode on the launch pad the instant the physics turn on, and the control vehicle just sits there; just like it says on the box. This will be a great help.

Structural panels, hmmmmmm. I'll check that out. Thanks! It is invaluable to have samples that exhibit the bug. So I can more or less assume I've stomped the bug if the samples start behaving. And I'm glad to find that the phorces was not my bug after all. Yes, I had a feeling the bug was due to saved vessels constructed with a previous version of the parts suite. Ah, I did not make myself clear. The magazines have collider meshes, but in their part.cfg file their "attachRules" have a value of 1 for allowCollisions. This allowed them to interpenetrate the old magazine rack's collider mesh without unfortunate side effects. In the current version, I carefully crafted the collider meshes on the rack to follow the contours of the rack. I kept the collider meshes on the rack frame to allow people to attach RCS and struts to the rack frame. Magazines have their mass recalculated after every bomb expenditure. If you look at the magazine part.cfg file you will see it has values for an empty magazine, plus a mass per bomb. Multiply mass-per-bomb by number of bombs, add the empty mag mass, and you have the current mass. In the latter kludge, this mass is removed from the magazine and added to the engine. If the magazine is jettisoned, the mass is removed from the engine and re-added to the magazine, before the magazine goes its merry way. If you can read C# code, this is handled in the file OrionMagazine.cs in the source code supplied with the mod. upMagazineMass() keeps the mass updated in the engine instead of the magazine, and if you jettison the function onPartFixedUpdate() removes the mass from the engine. Umm, actually if you look in the OrionMagazine code you will see I apply what I call "atomic clamps." These are "ConfigurableJoint" which I use to attach each magazine to the engine, said joints are set so they have their xyz motion and xyz angular motion set to a value of "locked". In theory this should have stopped the wobble, in practice it only greatly reduced it. NovaSililko said the Kerbal physics engine does not play well with dense objects (high mass + low volume) which perfectly describes the magazines. That is why I sucked the mass from the low volume magazines and injected it into the high volume engine. The vessel's overall mass does not change, so the performance should be unchanged. The problem was not that the joints were breaking. The problem was that the magazines were jerking around like they were on invisible tethers. But I will look to see if I can access the spring joints so I can increase the value of K.

Ah, well, what you say is true, in reality. The question is whether I can get the Kerbal physics engine to cooperate. When I tried landing on the plate under atom bomb power about a month ago, the shock detonated the engine. I tried using landing jacks, which did not help at all. That was when I noticed that the jacks did not move with the pusher plate animation. I probably have to play with the engine's part.cfg file, changing the crashTolerance or something. And try landing via weaker auxiliary rockets, like an LV-N Atomic Rocket Engine. Ah, by "phantom forces" do you mean the parts on top of the Orion engine chattering like Mexican jumping beans? Arrgh. I was having that problem with the magazines. With that, the problem was that the Kerbal physics engine did not like small dense objects on top of large uncompressed objects ("dense" meaning having high mass but low volume). I fixed that with a kludge, magically moving the mass from the magazines into the engine. So theoretically, the engine should be a massive but uncompressed object underneath your stack of landercan and cupola; everything should be fine. But as per your report, it isn't. Perhaps you could send me a *.craft file so I could try and mercilessly kill this bug? I'm sorry the mod is giving you problems. Ummm, can you please both go into more detail about part clipping? Was this with the Orion engine with the magazine rack on top or the one without? By "clipping" I assume you mean that some part stacked on top intersects with the engine. There used to be a problem if anybody used the engine with the magazine rack, and tried stacking another part on top of a column of Orion magazines. This was caused due to the unfortunate fact that there was a single collider mesh for the entire engine, and colliders cannot have concave holes in them. The hollows in the magazine rack were actually covered with the collider. The magazines did not collide because their part.cfg turned off collisions. I later used mulitiple collider meshes in order to allow concave holes, and the playtester reported that the problem went away. In the first picture, the green wireframe is the collider for the top of the engine. Any other part that intersects the green has "collided" with the engine. The second picture just shows the collider for the central column and the cap. The third shows the colliders for two of the side racks. Ooooh, that's excellent! Alas, no. Conventional explosives are not as efficient as solid or liquid fueled combustion, at least when it comes to specific impulse. The Orion works because nuclear explosives are more efficient.

And after I uploaded that update, I found it unexpectedly easy to make parts attached to the pusher plate move with the plate animation. But I'm not going to make another update until a few people have tried this one. That phantom bug concerns me. Other things I'd like to do include making the various atom bombs some sort of resource, so you can re-fill your tanks. The next update will let you attach landing jacks to the pusher plate, and the jacks will move with the plate. This will avoid the need to put your jacks on ridiculous outriggers. But in any event, trying to land under atom bomb power is a challenge. You can attach other things besides landing jacks, like extendable ladders so the Kerbals can make their way down the pusher plate as it glows blue in the dark.

New version for testing see first post for download. The bug scuttled away, I cannot reproduce it. Be on the lookout for Orion ships that when you move the focus to them apparently have dead engines. New Features: Users can now create their own magazine types and have them show up on the Orion Engine right-click menu. Engine now shows user flag Pusher cycle animation tweaked so it has larger extension. Added 20MN magazine. Removed 2MN magazine (nobody was using it). Made the 3.5MN magazine hold 60 bombs instead of 92. Lowered the mass of the 40MN magazines

arrgh and double arrgh. I was just about to release a new version when a rather serious bug popped up. Weird too. When you go to the Tracking Station, whatever Orion ship is first in the list has dead engines. That is, they will not respond to the Z key nor the throttle. All the others are fine. If you delete that vessel, the new top vessel has dead engines. There will be a delay as I try to track this down.

That would be fairly easy. A primitive prototype nuclear lightbulb would have a specific impulse of about 1870 seconds, thrust of 42 kN, and engine mass of 32 tons. T/W 1.3. Propellant is liquid hydrogen (seeded with tungsten particles) with a propellant mass flow of about 19 kilograms per second. Fuel is about 25 kilograms of uranium 235, which is burned at the miniscule rate of 0.055 grams per second (about 5.2 days of continuous burn time, the propellant will run out first). The uranium requirements can probably be ignored. http://www.projectrho.com/public_html/rocket/enginelist.php#id--Nuclear_Thermal--Gas_Core--Closed_Cycle The "liberty ship" heavy boost vessel is said to have Isp 3060 seconds, thrust of 5,340 kN, engine mass of about 54 tons. http://www.projectrho.com/public_html/rocket/surfaceorbit.php#libertyship

Thank you for your kind words. Let me know when your novels are published, I give them a read. It would be nice to have an Orion as an official part of the game, but they need some sort of draw-back. Otherwise they break the game, i.e., they make the game too easy and thus destroy the challenge. Maybe. Medusa has lots of advantages. But making a 500 meter umbrella is a bit of a challenge.