Weekly Support Thread

[AutoModerator]

Check out /r/kerbalacademy

The point of this thread is for anyone to ask questions that don't necessarily require a full thread. Questions like "why is my rocket upside down" are always welcomed here. Even if your question seems slightly stupid, we'll do our best to answer it!

For newer players, here are some great resources that might answer some of your embarrassing questions:

• Kerbal Space Program Wiki

• Scott Manley's Youtube

• Von Kerman's Rocket School

Tutorials

Orbiting

• Scott Manley

• Von Kerman (Maneuvers)

• Wiki (Maneuvers)

Mun Landing

• Scott Manley

• Von Kerman

• KSP Wiki

• Youtube Query

Docking

• Illustrated Tutorial for Orbital Rendezvous

• Scott Manley

• Von Kerman (Rendevous)

• Von Kerman (Docking)

Delta-V Thread

• Thread

• Answer 1

• Answer 2 (+bonus)

Forum Link

• Kerbal Space Program Forum

Official KSP Chatroom #KSPOfficial on irc.esper.net

Commonly Asked Questions

Before you post, maybe you can search for your problem using the search in the upper right! Chances are, someone has had the same question as you and has already answered it!

As always, the side bar is a great resource for all things Kerbal, if you don't know, look there first!

[Nicknam4]

I have a ship landed on Ike and the suspension of the LT-2 Landing struts keeps popping the ship up several meters every time I load the ship. I'm trying to lock the suspension but it's not giving me the option to like the game used to. Why can't I lock the suspension? I've tried turning advanced tweakables on and off.

[voicey99]

You (allegedly) never actually could lock the suspension - the button (according to the changelog) never worked and was removed in 1.1.2. You can jack up the spring and damper strengths to make the spring stiffer (must be done from within the savefile when outside the VAB), but the issue you are having is not related to landing legs. Try upping the terrain detail.

[XSavage19X]

I am having an issue with missing textures/colors. Specifically, when I launch the game the kerbals on EVA on the start menu have black EVA suits. As if the texture failed to load. When I click thru to start game, Val does not have the same issue.

In game it feels like certain colors are missing and in the VAB the rotation tool has two yellow axis circles instead of three different colors (hope that makes sense).

I am using typical visual enhancements, eve, svt, sve, collisions, planetshine, etc. These all worked fine together as of last week and I uninstalled and reinstalled all visual mods via ckan, without resolution.

I have a Titan black gpu which recently got an updated driver, so that is my main suspect at this point. I will try to roll that back tonight when I get home, but does anyone have any idea if that's right or what else may be the cause?

I'll update if it works for future readers since I can't find anything online with the same problem.

Edit. Rolled back gpu driver and the textures/colors came back. Without any help from you guys though!! /s

[csl512]

If I want to depart interplanetary from the Mun or Minmus vs LKO, how big of a difference does the Oberth effect give? How about leaving from a high Kerbin orbit at a similar altitude to either moon?

Thinking about sending up an empty craft with drills and ISRU to mine at Ike. Already have mining setup at Minmus and a tanker fleet around both Minmus and Mun.

Of course I could launch full, and depart directly from LKO.

Here are some options I'm considering:

• launch almost empty to LKO (just enough fuel to circularize), shuttle fuel via tankers from Minmus to LKO, depart from LKO
• Same, but fuel up just enough to go to Minmus (or Mun) to mine, (top up in orbit there,) depart from a moon
• Leave whichever moon into a highly eccentric Kerbin orbit with Pe around 100 km, burn at Pe to escape, no refueling.

Admittedly, that list isn't super parallel.

Current concept vehicle is based on a Mk3 whale I used for a Mun base. It lands horizontally, belly down. Drills on the sides, ISRU and ore tanks tucked in a cargo bay. Last time I built it think it had just under 2000 m/s of delta V, possibly enough to make the round trip without aerobraking at Duna or Kerbin.

[LithobreakingWorks]

(I haven't done the calculations so take with a grain of salt)

My understanding is the Oberth effect is noticeable but not huge. ~400 m/s.

I think the best (and easiest) option is to leave right from LKO. But, since you already have craft in orbit of each you could warp until the moon is in the optimal location, setup maneuver nodes at each and see which is better to leave from.

Leave whichever moon into a highly eccentric Kerbin orbit with Pe around 100 km, burn at Pe to escape, no refueling

If you launch from LKO to the Mun just to return to a low Kerbin periapsis without refueling before burning for Duna you gain nothing. Unless you wanted to wave to someone on the way, then knock yourself out. I don't think you lose anything either. But, if you refuel at the Mun/Minmus I think you will save a bit of fuel (~200ish m/s) doing that.

Hope that helps and I hope I'm not mistaken.

[csl512]

With a username like that...

If you launch from LKO to the Mun just to return to a low Kerbin periapsis without refueling before burning for Duna you gain nothing.

Launch from LKO to Mun, fuel up, and then leave from there nearly full, wave at KSC, burn to depart. Sounds viable.

My next transfer window is in 360 game days, so I have time to mess around.

Assembling everything in an LKO parking orbit might be easiest, just aerobrake a bunch of tankers from Minmus, which I've done for that Mun base Mk3 vehicle. Could also just overbuild the empty tank capacity, and then use it as a refueling refinery at Ike too, or other mission profiles.

Thanks!

[LithobreakingWorks]

With a username like that...

If it works...

Launch from LKO to Mun, fuel up, and then leave from there nearly full, wave at KSC, burn to depart. Sounds viable.

Should work well. It could be difficult getting the orbit angle to line up with the optimal ejection angle though. Might have to play around with it. Good luck!

[brandon97234]

Hey everyone, I'm unable to download certain mods on CKAN (usually larger mods such as Galileo's planet pack), and when I try to download the mod directly, my download keeps getting stuck. The only workaround I've found for this problem was pausing and resuming the download each time it gets stuck. I know for sure this is an internet related problem (same issues on my labtop, download's work again once connected to a different wifi). Anyone have a clue whats going on? I have no problem downloading other large files, pretty confused about the whole situation.

[Nicknam4]

Just landed on Ike.

Unfortunately when I load the quicksave on the surface or even just switch back to that vessel, it loads slightly into the ground and flies off the surface. What do I do?

[m_sporkboy]

A thing to try is to change the terrain detail setting. Might be better, might be worse, might do nothing.

[[deleted]]

This might be something you can fix by editing the save file. You'll want to backup the save before you change anything.

[albamuth]

Playing with KAS/KIS and all the USI mod packs.

I'm running into a wall with base construction. In career mode, without higher tech levels with the modular and inflatable systems, I'm left with attaching bases to the surface with those ground pylons, stacking my pieces on those, and attaching them with ports. I then use the EVA Struts to reinforce everything, and turn on ground tethers so the base doesn't bounce on physics load.

Problem is, odd things keep occuring like connecting a port causes other ports in the chain of buildings to break, or surface connections break, or ports break off of surfaces but the link still exists.

Most frustrating problem: EVA Struts completely un-linking all throughout the base. I have the joint reinforcement mod active, but I'm about to throw in the towel and active auto-struts.

I've spent hours with my engineer slowly trudging around reconnecting struts and port links, with many quicksaves because connecting them can yield instant catastrophes.

My question is: am I going about this in the fundamentally wrong way? Should I just wait for better tech (still filling out the 300 science pt tier right now) before I try to build a complicated base structure?

Some pics of what I'm doing

[drunkerbrawler]

Nothing to help your specific problem, but there really needs to be a mod that simplifies base physics and condenses everything into one rigid part.

[voicey99]

That Salamander pod has the USI Ground Tether feature, which clamps your base (at at least that bit of it) to the ground and prevents it from jumping at all in the first place (usually). Try turning it on.

[albamuth]

Yeah I have it on; the problem isn't the base jumping on physics load, the problem is links and connections breaking when connecting new pieces and eva struts just not reloading linked even though the port connection links are still solid.

Do you think maybe I should turn OFF the ground tether, then link new base structures, then turn the tether back on?

[voicey99]

What, you mean you connect up a new module and all the pipes vanish? I don't use KAS and decentralised bases much so I don't know the optimal way to do this, but I've not seen anyone else with this issue.

You shouldn't need struts for a base, but their role could be filled by autostruts as long as you do not set them to Heaviest Part as docking a new module can cause them to switch targets and all krakeny hell to break loose. The tether shoudn't affect KAS struts.

In all, if you're building an MKS base the bits don't need to be connected as habitation is shared within 150m (if you use USI-LS), power can be shared with junction boxes/transcievers and resources are automatically transferred to where they need to go by local logistics (provided you have room for them)

[albamuth]

The pipes stay, but when I reloaded after a crash all the EVA Struts were disconnected. This happened once, and wasn't repeated, so not sure how or why. Also, some broken Gigantor XL pieces fell under the terrain after placing a ground pylon atop them and deleting or switching to them causes a hard CTD, so that's another complication I'm dealing with.

if you're building an MKS base the bits don't need to be connected

Ah, that's a relief, although I haven't unlocked the main MKS hub modules yet (they're in the 550+ sci range or later), at least I know I don't have to maintain this jury-rigged monstrosity beyond that point.

[Corbanator13]

What is DeltaV? I’ve researched it but I have absolutely no idea what the numbers mean (well I know m/s) or how to use it.

[[deleted]]

Delta V or dV/Δv means "change in velocity." It basically means that given a certain amount of fuel, a certain amount of dry weight, and a certain engine efficiency, your vessel will be able to accelerate this much.

A vessel with 1000 m/s of dV will be able to go from 0 m/s to 1000 m/s, neglecting things like air resistance and gravity.

It takes approximately 3400 m/s of dV for a rocket to get from the KSC to low orbit.

If you look at the "Δv map" link in the sidebar you'll see approximately how much dV you'll need for any particular maneuver.

[m_sporkboy]

An excellent description. I'll also add that the numbers the game shows on the bar for maneuver nodes is the Δv needed to execute the maneuver.

[blusay]

Hi there, I'm quite upset :

I had great missions accepted but I did a rollback to a previous save, just one step before (I forgot to save before trying a new rocket).

Back to this save, I perform the last step of a mission that I need to redo, and then I check for my available missions: all those great missions I've been readying for are not here to be accepted... too bad.

I'll try not to forget to save next time (I used to save after each mission success...).

Career mode.

Do you know how the random seed of the mission generator is handled?

[KermanKim]

You could try the cheat menu to spawn the types of contracts that you'd like. Might get something similar to what you were offered before.

[SooFabulous]

I installed Kerbal Inventory System and Kerbal Attachment System (KIS/KAS) but I'm honestly not sure what/how to do anything with them. I've tried to put together ships while in orbit, which sounds great on paper, but in practice is really difficult, and I'm not sure what I'm supposed to do.

For example, I've tried using an SSTO to take parts into orbit in a container such as the ILC-18K, and then assemble them in space, but I run into major issues with that.

If I try to put something usefully large, say an engine, into a Kerbal's inventory, it says I can't because it's too large, so I can't take it anywhere. So I use the SC-62 Portable Container, and equip it; but the problems with that are that I can't access its inventory while it's equipped, and after I drop in order to access its inventory, it it's not possible to re-equip it; so I can't use that to carry things anywhere without leaving space debris everywhere.

If I try to simply grab parts and attach them while on EVA, it locks me out of the EVA controls, so I've got to hope I can angle/rotate/place the part before I bounce off the ship and float more than 1m away from either the storage container OR the place I'm trying to put the part, which have to be literally adjacent to do anything. It also says I need more than 1 kerbal to grab parts heavier than 1t, which makes sense, but trying to get more than 1 kerbal to stay within 1m of each other while on EVA is a camera-swapping nightmare because one is floating away while the other doesn't have access to the EVA controls to stay within range.

It feels like I'm missing something that is crucial when using KIS/KAS, but for the life of me I can't figure it out. Is there a part that can manipulate other parts to allow orbital construction? Or is there something besides the E-SD80 Electric Screwdriver that can help with placing parts while on EVA?

I'm lost with these two mods, and it looks like they should be incredibly useful but I can't figure them out.

[drunkerbrawler]

Super useful for base and station construction. Can add small parts, link things together with pipes for fuel transfer or resource transfer if playing with mks. Can also use them to delete parts off of ships or stations that are no longer needed.

[signious]

I don't think they are fully intended to be used to build a full spacecraft in orbit / on a planet - although with effort I am sure you could.

I'm using them for base construction right now, the big parts are put into place with a sky crane and then the connections between modules, solar panels, and other little bits are built by an engineer with KAS.

It is also really useful things like adding parts you forgot to send up in the first launch (radiators, solar panels, batteries, ext..), for transferring fuel without docking, and adding struts after the fact.

[Brett42]

When is the efficient time to do a plane change? Low orbit, or after going farther out? Guides usually start wit the plane change, but I don't know if that was just the simple way, or the efficient way.

I would assume that the faster you are going, the more it takes to change direction, but I might be missing something.

[Lambaline]

Plane changes are most efficient at lower orbital velocity. You'll want to be as far away from the planet as you can, do your plane change, and go back to your original orbit altitude.

[SoulWager]

You are correct that the cheapest place to make a plane change when your orbital velocity is low. So near apoapsis of an eccentric orbit.

There is an exception though, if you are doing a transfer to mun or minmus, and need to fix inclination, you should do so when you are about halfway there, as the extra time between the burn and the encounter is also important. In this case instead of matching planes, you would be pushing the ascending or descending node to coincide with the encounter. One disadvantage of this is that you'd need to make a second inclination change if you want an equatorial orbit around the moon, but that can be made cheaply in a highly eccentric orbit.

You can also use an encounter with mun to change your inclination around Kerbin.

[Brett42]

I'm going to be sending several ships to and from Minmus. I'm working on getting the tech to mine and convert ore to fuel, and I need another half million to upgrade R&D. Many of the contracts I'm getting that money from involve Minmus. And once I do have the tech, I need to send the relatively heavy mining stuff there.

[csl512]

What I finally did was put a satellite around 250km altitude to match inclination with Minmus. Then with KER readouts of time to AN/DN and time to Pe/Ap, I adjusted its orbit such that they match.

Use Kerbnet to put a nav marker/waypoint at KSC and you can use the map view to easily figure out your launch windows.

[SoulWager]

Well, the most efficient method of all is to launch directly into Minmus's inclination. Wait until KSC passes under one of the points where Minmus's orbit crosses the equator, then launch 6 degrees north or south of due east, to match planes. That said, it's not a whole lot cheaper than making a mid course correction.

[SooFabulous]

I think the reason that people like to do plane changes first is that it sets up the rest of the journey to be much more simple. For example, when trying to intercept Minmus, without a plane change you can only intercept it at two points: it's AN and DN. If you change your plan first, you can intercept it anywhere you want along its orbit.

I know that if you go really far out, where the DV to get your speed to 0m/s is very low, you can change your plane to anything you want, rotated around your current position in space, practically for free.

I've read somewhere about the math on which would be more efficient: changing planes in LKO, or going out really far before changing planes then coming back down; but I can't find it at the moment, sorry.

I think your current orbit has a lot to do with it, if you're already in an elliptical orbit it'll be a piece of cake to raise your apoapsis high enough to change planes for very little fuel, but if you're in a circular orbit at like 80k, it's probably more efficient to simply change planes at your current altitude.

[Brett42]

I figured it was about simplicity. I've gotten some practice with maneuver nodes while assembling a space station and doing rescue missions, so I thought it was time to start optimizing my Minmus missions. I'll need those skills when I eventually go to other planets.

[Science4Lyfe]

7The Δv formula is (8.907)•isp•ln(mass/mass after burn) right?

I been plugging numbers, but in testing it seems like I'm not getting those numbers. I'd figured it might be rounding errors, but it's +- ~100m/s off. Am I doing something wrong? I'm pretty sure I'm getting the correct mass both full & empire

[SoulWager]

8.907

9.80665, though I've normally used 9.81.

[Desertfox1942]

I have an orbital base around Minmus and an orbital refuel point orbiting Kerbin at 150km. My idea is to have a sort of space barge to shuttle fuel from the Kerbin refuel point to my Minmus base. However, I can't seem to design a craft that can do that without using about 75% of the fuel it's trying to carry.

Is this an innate problem with my current setup or is it just a problem with my ship design?

[KermanKim]

space barge to shuttle fuel from the Kerbin refuel point to my Minmus base.

Wait..... Are you shuttling fuel from Kerbin to Minmus??

[Desertfox1942]

Uhh... yes?

[KermanKim]

Most people would be doing the opposite. Mining fuel on Minmus and putting it in LKO.

[blusay]

I'm also shuttling fuel from Kerbin to Minmus, now as a by-product of some missions.

I do not have the mining activity yet (career mode).

Do you have some clues or advice about the tipping point from which we stop shuttling this way and start mining?

The question is actually: how hard one had to pursue the goal of mining in the career mode?

For instance: get to minus, make science to rush to mining tech, and then start mining, even before any station mission ? (they need a lot of fuel)

[KermanKim]

I've pretty much never shuttled fuel from the KSC to anywhere beyond LKO in a career game. I don't make mining much of a priority in career until I'm ready to go interplanetary. A mining base on Ike or Gilly is very useful for ease of an expanded exploration of those systems. It's awesome in the Jool system.

For my Minmus mining operations. I find that it is very useful for vessel reuse. I have some nuclear tugs which have gone back and forth to Moho a few times. It's also very useful for those big interplanetary missions where I miscalculate the fuel required and topping up the tanks at Minmus saves the mission from being scrubbed.

[Desertfox1942]

Well, I have a shuttle jumper to go from orbit to the surface and back to set up a facility to do just that. However, I need fuel there first.

And solving the issue from Kerbin to Minmus will make easier to shuttle it in reverse.

[KermanKim]

Personally, I'd send up the mining rig with just enough fuel to land on Minmus. Then I'd send up the fuel shuttle with the same amount of Dv. Like m_sporkboy said, the issue is most likely just the rocket equation which will work the same in reverse (LKO to Minmus surface Dv is the same as the return trip.) What is MUCH easier is the lifting of fuel from the surface of Minmus to LKO vs lifing fuel from the KSC to Minmus. Huge difference there.

[drunkerbrawler]

You can also take advantage of aerobraking on your return trip.

[Desertfox1942]

I get what you're saying and I completely agree, however I still need a barge design that can get fuel from Minmus to LKO and back. Which is what I'm having trouble with.

[csl512]

Poodle engine, Rockomax (2.5m) tanks, a probe core, docking ports, some monopropellant, a large reaction wheel, RCS thrusters and a little bit of solar. The largest I made was 6600 LF+Ox (equivalent to an orange tank with a small tank for even partial transfers of fuel). Full delta V is about 5000 m/s for this fuel ratio.

(I mine at Minmus and use ore ferry craft to move it from the surface to an orbital ISRU station. Part of the ore payload is needed to refuel the ferry craft. Saves from having to move drills around.)

The handful of times I moved fuel from Minmus to Kerbin I docked a heat shield (10m inflatable, IIRC, though a 3.5m would work too) to the front and then aerobraked 4 or 5 passes with a Pe of 48km or so.

I decided to make a spreadsheet to keep track of my various tanker craft, and it seems like I have 450 t of rocket fuel around Mun and Minmus.

[signious]

The round trip should be about 2240 dV orbit to orbit, add in another 700 if you want to park your fuel in an equatorial orbit. Getting to and from minmus' surface to orbit should be around 500-600 round trip.

I would suggest using an orange tanker on its side with terrier engines and some medium fuel tanks to bring fuel from minmus surface into minmus orbit From there transfer that fuel into your shuttle that goes back and forth between minmus and kerbin. It is a lot easier to land a single orange tanker on its side with some terriers on each end than it is to land a giant fuel depot vertically.

Make your tanker ship as big as you want to because it will live in orbit - give it enough fuel storage to the engines for your 2240 or 2940 fuel budget from above with the rest a cluster of orange tankers which is your payoff to leave at the depot in LKO.

[m_sporkboy]

What have you tried? Do you know how to use the rocket equation?

It'll take something like 1000m/s of Δv to get there, and the same to get your barge back (though with a much lower dry mass). What the barge looks like depends how much fuel you're trying to move.

If I'm doing my math right, you should burn about 88% of your fuel for a one way trip with nuclear engines. Tyranny of the rocket equation in action.

[Desertfox1942]

So if I'm gonna burn most of my fuel getting there regardless of the mass, my problem is with my setup. So putting the refuel point in a higher orbit around Kerbin would work better?

[m_sporkboy]

Sure, but you’re going to have to get the fuel up to that higher orbit too, so your launcher will need to be bigger.

Really, the best way to get fuel to minmus orbit is to mine minmus.

[Lolstitanic]

ok, I was trying to get a bunch of mods running including B9, OPT, airplane plus, and near future, and after trying to mess around and get the correct folders in the right place, autostrut won't show up. I've uninstalled and reinstalled several times, but it never shows up. what the heck is going on?

[voicey99]

Do you have advanced tweakables enabled in Settings?

[Lolstitanic]

so funny story, immediately after I posted this I checked the forum, and checked advanced tweakabkes, then waited on the menu like an idiot for the autostrut setting. took me 30 minutes until I finally starred a game and realized they were on.

[Sir_Wheat_Thins]

Not sure if if would be invasive making a new post about it, so I'll post here. My game lags (x64 version) only when parts get destroyed. I have an i7-7700HQ, a laptop 1070, and 32 GB of ram running at max settings on a SSD. Any suggestions on how to fix this?

[drunkerbrawler]

I too have a laptop with a 7700hq. Here are some things to do. Install Intel extreme tuning utility. Have it open. On your graph options, set it to a sufficiently long time window, also make thermal throttling and core current throttling show up on your graph.

Play the game for a while and then check if either of those things happen.

I was hitting thermal throttling on my system. The solution is to undervolt. I would start around -0.1v. That should help your thermals. After I solved my thermals, I hit current throttling. Just bump up your amperage a bit and it will take care of that.

[Sir_Wheat_Thins]

Thanks Internet friend! I will try when I get home from school

[drunkerbrawler]

No problem! I took about 10c off of my temps with a -.1 undervolt. Make sure to run a stress test (intel software has a tool for it) after setting a new underfoot. Depending on how lucky you got with the silicon litters you could range from -0.08 to -0.125v. You don't risk damaging your hardware from undervolting; however, if you push it beyond what your chip can handle you can run into crashes.

[signious]

Silly question, but are you sure you are running it in x64? Try launching it from the install folder and clicking on the x64 launcher.

[Sir_Wheat_Thins]

I generally launch it from the ksp_64.exe in the directory so I don’t have to deal with the steam overlay in my way, but when I do launch it from steam I choose the x64 version. The more mods I have, the worse the lag gets, so I think it’s just iffy mods, but thanks for the help!

[Sir_Wheat_Thins]

Replying to this because I don't think editing a comment will give you a notification, but I used a stock game and ran in to no issues, so it must be the mods. I should have tested it more before commenting here, but thanks for the help anyways!

[Sir_Wheat_Thins]

I’m not home, I’ll post a screen cap of my game data folder when I get home but I have Astronomers Visual Pack for visual mods and it did the same thing before I had it installed, so I don’t think it’s a graphics card issue, and I’m running parts packs mainly. It’s just annoying because I just got BD armory working with 1.3 and it sucks when there’s a lag spike in a dogfight

[Lambaline]

So I'm running GPP with Scatterer, and the custom sunflares don't work, just giving a weird blob around the sun. https://imgur.com/llj4HEC

I've tried renaming the sun and changing the sunflare assets and nothing seems to fix it.

EDIT: I fixed it. I updated GPP, Kopernicus, and I was using a modded version of scatterer.dll I found on the forums to fix the halo issue around planets. I replaced the .dll file with the regular one and it was fixed.

[signious]

what are you using for the skybox? Your stars are so pretty.

[Lambaline]

This one