RadHazard

For anyone who's still confused about waste heat management and can't wait for the update, here's the wiki page on the subject. I don't know what the relationship between the level of waste heat you have and your radiator's heat is, but I can tell you that if you correctly design your craft using the equations on the second half of that page, it will not overheat and shut down. The radiator page has all the information on radiator surface area. Note that the convection bonus on the inline and radial radiators has no effect on the radiator area. That simply means they will convect 20x as much heat per amount of surface area compared to the deployable radiators while in-atmosphere. That's only important if you are building a surface base or atmospheric craft. From what I can tell, I think he was asking for a more efficient replacement for monopropellant at higher tech levels that uses an alternative fuel source, e.g. liquid hydrogen heated by a reactor. That'd actually be pretty interesting. Maybe have a low-tech thermal version that had a low constant temperature and that drew thermal power from anywhere on the craft (to represent the heat-exchange system). It'd have more efficiency than monopropellant, but would require that there was a reactor somewhere on the ship. A high tech version could be a RCS-sized version of the plasma rocket with a low maximum power draw. Again, much more efficient than monopropellant (especially if you used liquid fuel for them, which would be fairly practical due to the lower thrust needed for RCS purposes). The only problem would be fuel flow if you used any fuel type that wasn't VESSEL_ALL_FLOW.

Have you tried leaving to the space center and then going back to the vessel? In some cases, I think the vessel doesn't properly update when you dock something to it. Also of note: If you didn't already know, you can place solar satellites closer to the sun benefit from the inverse square law. Halving the orbital radius in comparison to the sun gives you 4x the power production. Of course, setting that up requires lots of dV, so I would recommend starting out by using a fission power plant and an array of relays to start out.

If by staging you mean drop tanks, you can set up drop tanks the same way for both engines. If you mean dropping engines, then you can save some mass with the LV-Ns. I made the assumption that this craft would be used as a reusable interplanetary tug, which sounds reasonable for something that has 10 km/s dV with a 50 t payload. The numbers I posted were set to maintain close to the same engine mass and total ship mass. Here are more cases. They all assume a payload of 50 tons, as the reactor is only useful for very[/] heavy spacecraft. I've highlighted the numbers where one design was significantly better than the other. The conclusion remains the same. [B]Optimized to match engine mass and total craft mass.[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 50 t 20 45 t [u]0.45[/u] 172.81 t 267.81 t 8140 m/s Reactor 50 t 1 46 t 0.32 171.76 t 267.76 t [u]10000 m/s[/u] [B]Optimized to match engine mass and TWR[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 50 t 20 45 t 0.32 280.79 t 375.79 t [u]10800 m/s[/u] Reactor 50 t 1 46 t 0.32 [u]171.76 t[/u] [u]267.76 t[/u] 10000 m/s [B]Optimized to match engine mass and dV[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 50 t 20 45 t [u]0.36[/u] 244.38 t 339.38 t 10000 m/s Reactor 50 t 1 46 t 0.32 [u]171.76 t[/u] [u]267.76 t[/u] 10000 m/s [B]Optimized to match TWR and total craft mass[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 50 t 14 [u]31.5 t[/u] 0.32 184.82 t 266.32 t 9300 m/s Reactor 50 t 1 46 t 0.32 [u]171.76 t[/u] 267.76 t [u]10000 m/s[/u] [B]Optimized to match TWR and dV[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 50 t 17 [u]38.25 t[/u] 0.32 227.02 t 315.27 t 10000 m/s Reactor 50 t 1 46 t 0.32 [u]171.76 t[/u] [u]267.76 t[/u] 10000 m/s [B]Optimized to match dV and total craft mass[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 50 t 11 [u]24.75 t[/u] 0.25 192.29 t 267.04 t 10000 m/s Reactor 50 t 1 46 t [u]0.32[/u] [u]171.76 t[/u] 267.76 t 10000 m/s Note: Assumes 3.75m unupgraded fission reactor with Thorium fuel For the sake of completeness, here's the same calculations with a 10 t payload (suitable for a heavy probe) and 6 km/s dV (suitable for a round trip to most planets), which show the situations in which the LV-N shines. [B]Optimized to match engine mass and total craft mass.[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 10 t 20 45 t [u]1.03[/u] 63.06 t 118.06 t 6000 m/s Reactor 10 t 1 46 t 0.73 62.40 t 118.40 t [u]7400 m/s[/u] [B]Optimized to match engine mass and TWR[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 10 t 20 45 t 0.73 117.17 t 174.42 t [u]8750 m/s[/u] Reactor 10 t 1 46 t 0.73 [u]62.40 t[/u] [u]118.40 t[/u] 7400 m/s [B]Optimized to match engine mass and dV[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 10 t 20 45 t [u]0.86[/u] 86.10 t 141.10 t 7400 m/s Reactor 10 t 1 46 t 0.73 [u]62.40 t[/u] [u]118.40 t[/u] 7400 m/s [B]Optimized to match TWR and total craft mass[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 10 t 14 [u]31.5 t[/u] 0.73 75.64 t 117.14 t [u]8150 m/s[/u] Reactor 10 t 1 46 t 0.73 [u]62.40 t[/u] 118.40 t 7400 m/s [B]Optimized to match TWR and dV[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 10 t 10 [u]22.5 t[/u] 0.73 [u]50.88 t[/u] [u]83.38 t[/u] 7400 m/s Reactor 10 t 1 46 t 0.73 62.40 t 118.40 t 7400 m/s [B]Optimized to match dV and total craft mass[/B] Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 10 t 16 [u]36 t[/u] [u]0.82[/u] 72.01 t 118.01 t 7400 m/s Reactor 10 t 1 46 t 0.73 [u]62.40 t[/u] 118.40 t 7400 m/s Note: Assumes 3.75m unupgraded fission reactor with Thorium fuel The last three entries in each table are of the most interest. You would choose TWR if it matters to you how long your burns will take. You would choose Total Craft Mass if it matters to you how much weight you have to lift into space. You would choose dV if it matters to you how long you can go without refueling. You can pick two to equalize, and let the third float. For TWR + Mass: The Reactor has more dV when it comes to the heavy payload. The LV-N has more dV when it comes to the light payload. For TWR + dV: The Reactor leads to a lighter total craft for the heavy payload. The LV-N leads to a lighter total craft with the light payload. For dV + Mass: The Reactor has a higher TWR with the heavy payload. The LV-N has a higher TWR when carrying the light payload. It seems that without a doubt, the LV-N is superior for light spacecraft in almost every way, and the Reactor is superior for heavy spacecraft in almost every way. ...whew. I really need to program this sort of analysis ability into my calculator.

That doesn't matter in the context of my calculations. I was comparing one reactor + thermal nozzle to an equal weight of LV-Ns, which would have the same mass ratio. You are correct in stating that smaller craft will be better off using LV-Ns. The point at which Reactors + Thermal Nozzles become useful is the point at which you need to attatch 20+ LV-Ns to your rocket to get an acceptable level of thrust, assuming you're using the 3.75m reactor. I played around with my Transfer Stage Design calculator and got these numbers: Payload Mass # Engines Engine Mass TWR Fuel Mass Total Mass dV LV-Ns 50 t 20 45 t 0.46 178.07 t 263.07 t 8000 m/s Reactor 50 t 1 46 t 0.32 181.76 t 267.76 t 10000 m/s The conclusion I draw from that is this: If you want to send a single interplanetary probe, use LV-Ns. They're lightweight and flexible. If you want to launch a manned mothership that can fly to each of Jool's moons, send a lander, and then return to Kerbin all in one go, use a reactor. It's much more powerful.

You have to upgrade reactors to get anything useful in vacuum.This isn't quite true. The un-upgraded fission reactors CAN be used as thermal rockets, but you will need to use either the 2.5m or 3.75m reactor and use Thorium in order have an engine more effective than the stock LV-N. The stock LV-N produces 60 KN of thrust and has an ISP of 800 s. It's base thrust-per-ton is 26.6667 KN/t. The 3.75m reactor produces 849.77 KN of thrust at full power using thorium and liquid fuel. It weighs (when fully loaded with uranium) 43 tons + 3 tons for the thermal rocket. This gives it an effective TPT of 18.4733 KN/t and an ISP of 993 s. Assuming a rocket with the same engine mass (i.e. 1 3.75m thermal rocket or ~20 LV-Ns), you will have just under 70% the thrust but around 125% of the dV. If you swap out liquid fuel for LFO, you get 3,144.15 KN of thrust with an ISP of 595.8 s. This gives you an effective TPT of 68.3511 KN/t. Compared to an equal weight of LV-Ns, this would give you 256% of the thrust, but you would only have 75% of the dV. The 2.75m reactor isn't very useful with pure liquid fuel and thorium, as it has only 141.63 KN of thrust, with a weight of 14 t + 1.5 t for the thermal rocket. This gives it the same ISP of 993 s but a TPT of only 9.1374 KN/t. Compared to an equal weight of LV-Ns (~7 LV-Ns), you would have only 34% of the thrust and 125% of the dV. Using LFO gives you 524.031 KN and again an ISP of 595.8 s. The TPT of this is 33.8085 KN/t. Compared to an equal weight of LV-Ns, you will get 127% the thrust but 75% of the dV. The only advantage of using the 2.75m reactor over the 3.75m is that it is smaller and thus more suitible for smaller interplanetary craft. Overall, unupgraded fission thermal rockets are possible, but only advantagous when you are carrying very large payloads. I would recommend using them to build large interplanetary tugs. As for plasma engines, those are a different beast entirely. Self-sufficient plasma engines are more-or-less useless until you get either fusion reactors or microwave-transmission. I recommend starting with this guide on the wiki, which assumes you have microwave transmission unlocked. If you chose to unlock fusion reactors before microwave transmission, I recommend using the 1.25m fusion reactor, the 67.5 cm plasma engine, and lithium for the fuel. Try that combination with a minimal payload (e.g. just the 1.25m capsule or something) and see how that works for you. It will work much better once you unlock upgraded generators (which are in the node after microwave transmission, I believe) Actually, Fractal_UK has a working solar sail. It'll be included in the next version. The post about it is here

KSP Interstellar is a great mod for extending the end-game portion of career mode. Almost all of the parts in that mod are in their own nodes in the tech tree, further down the end than the stock tree goes. Most of the engines included in that pack are fairly overpowered compared to stock engines, but I would consider it balanced extremely well due to the extra research requirements to unlock them and the fact that most of the more powerful engines require dedicated resource collection missions. It doesn't do much at all for the early game, but once you get to the point where you've already unlocked most of the stock tech tree, it gives you a lot more stuff to do. I would definitely recommend it.

Actually, I think in some cases they do. I think in cases where you are far enough away that you are starting to get distance losses, the second receiver is capable of "picking up the slack", so to speak, letting you get full power from further distances. DISCLAIMER: I have not actually tested this. I was diving through the source code earlier and I'm simply speculating that this is what will happen. Normally, yes. That's how most NTR propulsion works. However, there have been real-life proposals to use LOX-augmented NTRs to have significantly greater thrust at an expense of lower ISP. The theory is to take oxidizer and pump it into the nozzle just after the reactor where it combusts with the super-heated fuel, similar to how an afterburner works. A lot of papers on the subject are behind paywalls, but I found an abstract for one paper that claimed a 440% thrust output with a 45% ISP compared to standard NTRs, very similar to the performance of LFO mode in KSPI thermal rockets.

That will help, but I was referring to geostationary (or keostationary, if you prefer) satellites. That way, they'd always be in exactly the right spot over KSC. You could have one more or less directly above KSC, another one about 20-30 degrees east, a third the same distance away, and then maybe one positioned in a good spot for your circularization burn. If you need more coverage, you could either put more or space them out. Stationary orbit is about 2,868.75 km up, though you'll get better accuracy if you use an information mod and get the orbital period to be only a few seconds plus or minus 6 hours.

Why not stick some relays in a stationary orbit over KSC? You can space them out so that you get good coverage over your entire launch profile. You won't get perfect 100% transmission, but you could always increase your power supply somewhat to make up for it.

The size of the receiver determines how efficient they are at long distances. After a certain distance from the transmitter (I haven't tested it so I don't know the exact value), they will begin to lose efficiency. The larger receivers can be farther before starting to lose efficiency, and their efficiency drops slower. Note that this only affects receivers. Transmitters and relays are unaffected by the size. In this case, you need two transceivers. One set to relay mode and one set to transmit mode.

Relay mode doesn't work that way, I'm afraid. When a transceiver is set to relay mode, it acts as a mirror for microwave transmissions, meaning it just bounces incoming transmissions. It doesn't receive or transmit any power of it's own. Can I ask what you're specifically trying to do? In most cases, it should be possible to just have a single transceiver and swap it between receive, transmit, and relay mode as necessary.

I've never had any problem hotlinking images on the wiki. If you're worried about where to host the image, you can always just stick it on imgur.com or something. Oh, and it looks like you missed one thing: Electrolysing Alumina produces oxidizer in addition to aluminum. Otherwise, great chart!

I've personally never understood the appeal of mod packs. It's certainly easy enough to simply put together a list of mods that go well together. Actually compiling all the files together in a single download saves some time for the end user, but requires the maintainer of the pack to keep it up to date. The issues that out-of-date mods can create are, in my opinion, potentially more harmful than whatever benefit you get from the packs themselves. Compatibility is one good reason, but I'd prefer that mod creators adopt some sort of community standard, rather than a third party individual attempting to create a workaround to make everything work together. It's more maintainable, as it doesn't need someone to update it every time someone releases a new version of a mod, and it's easier for any new mod-makers to ensure their mods are compatible with what currently exists. That being said, I don't see anything unethical about it as long as you have permission from the creators of the mods you include.

Power decay over long distance actually does exist in this version. Each antenna has a maximum range, beyond which power decays. I don't know what the range for each of them is, but I do know that you can't receive full power at interplanetary distances using the smallest receiver. From what I remember, I believe the distance is measured as the distance of all the relay hops added together, so relays don't act as "repeaters". I'd say a good balancing measure would be to simply make the larger relays heavier, as I agree they are fairly light-weight. I also agree with your statement that heat should still accumulate over time for deselected vessels, although I know there are technical issues to that. Perhaps a simple check as the vessel is offloaded to see if it has the capability to stabilize (using the data from the new heat management window, perhaps)? If it doesn't just automatically disable relay/transmission for that ship. As for spamming nuclear reactors on the ground, that should hopefully be balanced by the inclusion of the rest of the economy, which I believe is going to happen in the next version of KSP. Atmospheric decay is (I think) already modeled, so presumably space-based power generation is more efficient (assuming you can make the launch cost-effective). If it's not, the inclusion of that would help as well.

Easiest method to make a reliable relay network is to put 3 equally spaced relays in an orbit 120 degrees apart from each other and at least 700 km high. Technically you can go as low as 600 km (equal to Kerbin's equatorial radius), but going higher gives you some margin for error. In this configuration, any craft in an equatorial orbit can see at least one relay, and most of the time two. Each relay can also see every other relay, so this means a receiving craft can connect to every transmitting craft in equatorial orbit around Kerbin via the relay network. If you want perfect coverage for polar orbits you'll need to do something fancier, e.g. Molniya orbits. As for how the transceivers function: Transmitters and Relays are not directional. Since they are on separate craft, it is abstracted away and assumed that they rotate to provide optimal coverage. Receivers are directional, and must be pointed toward the transmitter or relay to get the best efficiency. As your angle increases, your efficiency drops, eventually going to zero at a 90 degree angle or above. I recommend putting several receivers on your craft and rolling just before any burns in order to find the angle that provides the most power. Relay satellites only need one transceiver, set to relay mode.

I've had good results with just putting 3x symmetry receivers around my craft that face slightly backwards and a fourth receiver pointing forward. I've found that you can usually get an angle that will give you a decent percentage of power, especially if you have a powerful network as Deredere mentions. I've only tested in LKO with a relay constellation though, so I don't know the best way to do it if you're trying to go interplanetary.

The higher you go, the greater your ISP becomes. This means at first, you will notice your thrust increasing as you climb (since KSPI engines' thrust is dependent on ISP). Once you hit a point where your intakes produce less air than your engine(s) can consume, your thrust will decrease. Going faster will give you more intake air to somewhat counteract this. I don't know the exact formulas off the top of my head, but you can see the amount of intake atmosphere intakes produce by right-clicking them, and you can check the power level of the reactor to see if you are utilizing it fully.

Actually, there's been some debate as to whether the stock resource units are in fact liters, given how extraordinarily dense that would make liquid fuel and oxidizer compared to most known rocket fuels. There was a thread in the mod discussion board debating it when trying to come up with a standard for mod resources. However, I can say for certainty that yes, 1 unit of liquid fuel weighs exactly 5 kg. Oxidizer weighs the same as liquid fuel.

Yes, in sandbox mode you have the upgraded fission reactors from the beginning. I'm not really sure why this is an issue, since there's no reason to balance sandbox mode around any particular level. In any case, there's still the issue of thrust with fission-powered thermal nozzles even in sandbox mode. Additionally, you have the plasma engine, DT-Vista, antimatter reactors, and the warp drive unlocked, all of which are far superior to the fission-powered thermal nozzle anyway.

I would love something like this. In my very first save file, I saved every iteration of my ships under a new name, and even if I never had to use them, I still enjoyed looking at all the old versions just to see how the design was refined as it was built. In later save files I stopped doing this because it ended up filling up my ship list very quickly, and it was tough for me to remember to change the version number before saving every single time. I'd also like a separate categorization system in addition to per-craft version archives, preferably with custom categories. It'd be nice to be able to have all my supply craft in one category, my space tugs in another, my one-shot science missions in a third... etc. If the same systems also applied to subassemblies, even better.

It's actually not. In order to get 2800 ISP, you need to upgrade them, which requires you to research fusion reactors first. Otherwise, they have an ISP of 915 using pure liquid fuel, which puts them only slightly above the stock LV-N, and is more than balanced out by their significantly lower thrust. It's actually fairly difficult to find a niche where the unupgraded 1.25m fission reactor outperforms the stock LV-N. I don't really see this as a problem though, since the way fission reactors scale, the 2.5m and 3.75m are useful for thermal rocket nozzles, and the 1.25m is still useful for thermal turbojets and producing large amounts of electricity. In addition to the balancing factor of extra research, they still produce less thrust than an equal weight in LV-Ns, even when upgraded. Even using LFO, the 1.25m reactor has only about half the thrust of an LV-N for a very similar weight, and the ISP drops to 1675. Once you get past fission and into fusion and antimatter, yes, the nozzles do get much more powerful compared to the stock LV-N. However, at that point, you've clearly surpassed the tech level of the LV-N (And invested a lot of science points in doing so), so it doesn't seem problematic to me. This is definitely an end-game mod.

I can confirm that this also happens to me. Regardless of what keys I press in docking mode, I always end up at half thrust in staging mode. It might be a mod issue, as I have several mods installed. I haven't tried narrowing it down yet though.

The mod actually already does this. Here's a list of all upgradable parts: Experimental Electrics Electric Generator: Brayton Turbine → KTEC Thermoelectric (better efficiency) Heat Radiator: Mo Li Heat Pipe → Graphene Radiator (better efficiency) Fusion Power Nuclear Reactor: Solid Core Reactor → Gas Core Reactor (3x power output) Thermal Turbojet: Atmospheric Thermal Jet → Hybrid Thermal Rocket (Basic version can only work in atmosphere, Upgraded version can toggle over to internal fuel) Antimatter Power D-T Inertial Fusion Reactor → High-Q Intertial Fusion Reactor Ultra-High Energy Physics Antimatter Reactor: Solid/Liquid Core Reactor → Liquid/Plasma Core Reactor (3x power output) Plasma Thruster: Magnetoplasdynamic → Quantum Vacuum Plasma Thruster (uses no fuel) Note that technology upgrades only apply to newly launched parts; parts on existing ship will need to be upgraded individually. Individually upgraded parts (must always be upgraded manually using science): Alcubierre Drive: Standard Field Geometry → Advanced Field Geometry (Faster charging times and higher maximum speeds) Computer Core: Standard Mainframe → Artificial General Intelligence (AGI) Core (Guaranteed to open the pod bay doors while within warranty period!) I have also encountered that issue with generators automatically becoming charged power generators. The antimatter reactor, however, doesn't appear to be an issue so much as an odd quirk of the resource system. It appears that the unused thermal power the fusion reactors are producing are filling up the antimatter reactor (as thermal power has VESSEL_ALL_FLOW). The generator attached to the reactor is able to make use of this thermal power as if the antimatter reactor were producing it. I assume that if you were to do something that demanded more power than the fusion reactors could provide you would starve the antimatter reactor of it's bleedthrough thermal power. I can't speak about using Romfarer, but I do know an easy way to aim yourself is to target the planet and use the pink guide markers on the navball to point yourself directly towards it.

This isn't entirely true. The same node that gives you upgraded radiators also gives you upgraded generators. Since actual generator efficiency is equal to (1 - Radiator Temp / Reactor Temp) * Theoretical Generator Efficiency you will still get double the electricity out of ship designs using the same number of radiators, due to the significantly higher theoretical generator efficiency. The upgraded radiators are also better for dissipating heat in situations where you don't need to use a generator, e.g. low-kerbol solar satellites, microwave receivers, and thermal rockets.

A fair point. However, you will still need to lift the other 860 tons, which would take somewhere around 8600 tons of launch mass. Either way, it's roughly a 2% mass savings. A 2.5m NERVA would be good for saving on part count (which is always good), but otherwise it's possible to build a ship with very similar performance right now.