nyrath

@DDE: but what astonished me was this bit I found here: Now, DDE, you are probably aware of all this, but this was a wake-up call for me, and I am also speaking to others on this forum. Solid fuel rods, such as are using in the old NERVA solid-core NTR, become clogged with nuclear reaction products (neutron poisons) when 15% of the fuel has been burnt (undergoing nuclear fission). A clogged rod will not support nuclear fission. The rod has to be removed and taken to a reprocessing plant. For this reason NASA's reusable nuclear shuttle has an engine life of only 10 Terra-Luna round trips before disposal, even though the rods still contain 85% of the expensive uranium-235 unburnt. Extracting the rods for reprocessing is too dangerous in NASA's eyes, they just send the nuclear shuttle into a graveyard orbit. This wastes a lot of expensive U235. The same limit applies to a nuclear power plant. Ground based plants periodically halt operations when the solid fuel rods become clogged. They then spend a few months carefully opening the reactor, removing the clogged rods, replacing them with fresh rods, then carefully reassembling the reactor. The clogged rods are sent to a reprocessing plant to extract the unburnt U235 and using it to fabricate fresh rods. The rest of the rod goes to a long term nuclear waste disposal site. If I am reading the above sentence correctly; they are implying that the fuel gas, after one pass through the MHD generator, can be passed through an on-board refinery. The product is already gaseous, as opposed to solid fuel rods, which simplifies refining. In the refinery the nuclear reaction products clogging the gas can be filtered out, and the unburnt U235 can be sent on another pass through the MHD generator. The alternative is removing the gas "from the circuit to the external environment", i.e., wastefully jettisoning the gas into deep space along with all its expensive unburnt U235. Now that my nose has been rubbed in the fact, I realize that a nuclear lightbulb gas core engine should also require an on-board reprocessing plant. But in all the nuclear lightbulb documents I've read, a re-processor is conspicuous by its absence. I'm going to have to review the documents.

DDE, I am so sorry I missed this, so many years ago. This it fascinating information! Thank you so much!

I'm trying to get a fixed package together for this week. The nodes have to be flipped, temperature hook changed, needs a place in the tech tree, and the new source code added to the package. Sorry I'm taking so long.

Rats, bombs won't go off in v1.0. Am looking into it.

Scott Lowther is asking around as well. Not good, not good at all. http://up-ship.com/blog/?p=28354

Lord_Chappington, when you right-click on a magazine, does the pop-up menu say it is "feeding?" Did you try firing off bombs by both using the Z key and using the throttle? Neither worked?

It is looking mighty fine, TiktaalikDreaming! You are doing a good job recreating the original Orion exploration craft. I am impressed.

I was thinking about doing the same thing: making the internal bomb supply something the size of a matchbox that you attach. Keeping in mind that the magic bomb management code changes a bomb magazine's mass dynamically, as bombs are taken out. So that matchbox will have a mass of tons. Be cure you mount it on the thrust axis of the engine units, or the ship may be unbalanced.

gmiezis, that is stunning artwork! but you'll have to pardon me, I've got something in my eye. Dusty in here.

Good work TiktaalikDreaming! Adding internal storage pulse units will be a pain. The module code will have be be altered, and unfortunately I do not have time to do it (the source code is supplied with the mod, of course). The trouble is the tricky coding used so that the mod magically found any attached pulse unit magazines and set the engine up to consume their pulse units. And keep the different sizes of pulse units separate.

Porkjet! Your mods are beautiful pieces of work! I am most impressed. I placed your mods in the Atomic Rocket Seal of Approval section: http://www.projectrho.com/public_html/rocket/sealofapproval.php#id--Computer_Simulation--Porkjet's_Nuclear_Lightbulb_KSP_Mod

I'm sorry I'm to busy to help right now, but there are some notes and diagrams about the 10-meter USAF Orion that the mod is based on here: http://www.projectrho.com/public_html/rocket/realdesigns.php#id--Project_Orion--USAF_10_Meter_Orion Using Blender: [1] The rule is: One hand on the mouse, the other on the keyboard [2] This means you have to memorize lots of hot keys [3] Print out a list of important hot keys http://www.dummies.com/how-to/content/blender-for-dummies-cheat-sheet.html http://blendertips.com/hotkeys.html [4] Tape them to the wall next to the computer monitor [5] Start doing some tutorials http://www.blender.org/support/tutorials/ while frequently referring to the cheat sheet. One hand on the mouse, the other on the keyboard. [6] For about a week you will feel like you are pounding your head on the wall. Then one fine day you'll try Blender again, and suddenly it will be childishly easy

My life is still in total chaos, so I have not had a chance to work on things. Alistair Young alerted me to the fact that the mod will not work in .90 He has temporarily fixed it for me. There is a drop-in replacement for the dll here: https://github.com/cerebrate/USAFOrion/releases the code is here https://github.com/cerebrate/USAFOrion I'll try to merge this into the main release Real Soon Now

That is a very good question. Alas it is above my pay grade. I'm unsure about phased arrays at optical frequencies.

The thing that commonly gets ignored in futuristic depictions of space combat is the awkward necessity for huge heat radiators. Weapons like lasers, particle-beam weapons, coilguns, railguns, and the like requires huge amounts of power. Nuclear reactors that can supply such power will also generate huge amounts of waste heat. The weapons will generate waste heat as well. Laser cannon are notoriously inefficient. Free-electron lasers have a theoretical maximum efficiency of 65%, while others are lucky to get a third of that. This means if your beam power is 5,000 megawatts (five gigawatts), and your cannon has an efficiency of 20%, the cannon is producing 25,000 megawatts, of which 5,000 is laser beam and 20,000 is waste heat! Ken Burnside describes weapon lasers as blast furnaces that produce coherent light as a byproduct. Rick Robinson describes them as an observatory telescope with a jet engine at the eyepiece. The only three ways of getting rid of heat are convection, conduction, and radiation. And the first two will not work in space since space is a vacuum. This means you are stuck with using huge heat radiators. The problem with heat radiators are that not only are they huge targets, they are very difficult to armor. http://www.projectrho.com/public_html/rocket/spacewardefense.php#radiators The thinking is that when going into combat, the spacecraft will retract their radiators and rely upon internal heat sinks to temporarily store the waste heat. Trouble is that they probably will not be able to store more than a few minutes worth of heat. If a ship's heat sink fills up, the ship has a choice of: [1] The ship melts, killing everybody aboard and destroying the ship [2] The crew surrenders, "striking the colors" by extending their radiators and ceasing fire.

Yeah, me too. Personally I blame Star Wars and the Wrath of Khan movie. http://www.projectrho.com/public_html/rocket/spacegunexotic.php#id--Space_Fighters--Role

Agreed. Much like the Eagle transporters from the TV show Space 1999. They were cargo vessels that got laser weapons stuck on with duct-tape. The analogy is how the original wood and fabric biplanes were gradually adapted to be used as war machines in WW1 http://www.projectrho.com/public_html/rocket/spacewarship.php#id--Ship_Design_Analysis--Arthur_Majoor's_Analysis

Yes, this is called a "torch missile." The point being that it is much easier to have a deltaV of X if the item does not need mass for crew, life support system, consumables, habitat modules, and so on. A missile with more deltaV than a full-fledged spacecraft would be cheaper than the full-fledged spacecraft. Of course a torch missile is more expensive than a conventional missile. But a torch missile can chase the target all over the solar system, and cannot be evaded because it has more deltaV. Even if it takes a few months. Torch missiles cannot be evaded, you have to destroy them with point defense or something.

Unfortunately that turns out not to be the case. As mentioned before, while lasers are not subject to the inverse square law, they are subject to diffraction. Which has much the same effect. http://www.projectrho.com/public_html/rocket/spacegunconvent.php#id--Laser_Cannon--Equations

Depends upon what you mean by "fleet". Conventional nuclear weapons radiate damaging energy isotropically which is good for taking out lots of ships in a compact formation. Unfortunately this means the damage is subject to the inverse-square law. Nuclear weapons detonated on Earth, that is in a place with an atmosphere, do most of their damage with "blast" (i.e., the x-rays are absorbed by the air, this superheats the air, resulting in blast). There ain't no air in space so the damage has to be done with x-rays. Bottom line is if your spacecraft is more than about a kilometer from a standard sized nuclear weapon, the only damage it will suffer is some scorched paint. So you can have lots of ships in a compact formation if by "compact" you mean "spaced with two kilometers of separation" http://www.projectrho.com/public_html/rocket/spacegunconvent.php#id--Nukes_In_Space--Warhead Yes, lasers can hit targets from huge ranges. Problem 1: while lasers are not subject to the inverse square law, they are subject to diffraction. This has much the same effect, weakening the power density of the beam with range. http://www.projectrho.com/public_html/rocket/spacegunconvent.php#id--Laser_Cannon--Equations Problem 2: if the targets are maneuvering (i.e., dodging), and the range becomes more than a few light-seconds, you will not be able to hit the target except by accident. You will only see where the target was, not where it is right now. And not where the target will be when the laser bolt finally gets there. http://www.projectrho.com/public_html/rocket/spacewardefense.php#id--Evasive_Maneuvers

Well, yes. And aircraft can be maneuvered as if they were old-school seagoing battleships, trying to cross the "T" and firing broadsides. Airplanes do not maneuver that way because it is not very effective, and contrary to their nature.

Yes, you are correct. I was speaking off-handedly.

If you ever find the equation for the relationship between Z and the blast angle, let me know. I'd like to know myself. Apparently it is still classified. Yes, of course the blast will dissipate, as long as the blast angle is greater than zero. The blast will dissipate with distance proportional to the tangent of the blast angle. The casaba howitzer was a candidate for President Reagan's Strategic Defense Initiative. So it had a theoretical range suitable to pick off Soviet ICBMs coming over the horizon. The estimate I saw was 6.276 × 10^12 joules per bolt, which is quite a bit better than any laser weapon currently on the drawing board.

Sorry I'm coming into the discussion late. The various weapons seem have been discussed, with the glaring exception of the casaba howitzer. This is a weaponized version of the nuclear pulse units used by the Orion nuclear pulse engine. It is a nuclear shaped charge directing about 85% of the blast energy in a narrow burst at the target. I have a few notes here: Introduction to Space Warfare Detection in Space Warfare (but first read Nicoll's Law) Introduction to Space Weapons Conventional Space Weapons Exotic Space Weapons Defenses in Space Warfare Space Warship Design Space Warfare Strategy and Tactics Planetary Attack

A Kerbal Nomogram What's a nomogram? It is an obsolete calculating device about the same vintage as a slide rule. You do not see them much anymore because I wasn't kidding about them being obsolete. But educators on a budget might find this useful. Or not. It is printed piece of paper optimized to do one single mathematical calculation. It is a series of printed scale that you place a ruler or other straightedge over to solve the equation. Download this and print it out. And if you spot any mistakes, let me know so I can fix them. https://copy.com/bpqGFdh6XxUH This particular nomogram solves the delta-V equation: dv = Ve ln® That is, there are three variables: delta-V, Isp (or exhaust velocity), and mass ratio (or fuel percentage). Given any two variable, the nomogram will tell you the value of the third. Example: Say your spacecraft has engines with a specific impulse (Isp) of 320 seconds. You want to do an orbital transfer from Kerbin to Dres (1,300 meters per second). Place the nomogram on the table. Lay a ruler over it so that on the Specific Impulse scale (the one on the left) it crosses the 320 second mark. Pivot the ruler so that it simultaneously crosses the Delta V scale (the one in the middle) at the 1,300 mark (labeled "Kerbin-Dres xfer 1,300 m/s). Look at where the ruler crosses the Mass Ratio scale (the one on the right), and you will see it does so at Mass Ratio 1.51 (a tad less than 34% fuel). Now, there is one application where a nomogram has an advantage over a calculator. It allows you to visualize a range of solution. If the mission is an orbital transfer from Kerbin to Dres, you can place the ruler on the 1,300 m/s mark on the Delta V scale, and pivot it there. This allows you to see how changing the specific impulse of the engine affects the propellant fraction, and vice versa. Remember that exhaust velocity equals specific impulse times 9.81, and propellant fraction = 1 - (1 / massRatio)