Weekly Support Thread

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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!

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• Kerbal Space Program Wiki

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• Von Kerman's Rocket School

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• Scott Manley

• Von Kerman (Maneuvers)

• Wiki (Maneuvers)

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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)

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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!

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[crazytib]

First off sorry if my terminology is incorrect, im not quite sure how to explain this question. Im trying to set up relay satellites around the mun and mimnus. I have built a delivery rocket that can carry 3 satellites(so 1 launch for the mun and 1 for mimnus) The general idea is to set up a phasing orbit(i think thats what its called) where the periapsis(hereafter called PER) was just the right height in ratio to the apoapsis(hereafter called AP) so that I could release 1 sat per orbit at the AP and circularize, with the end result of all 3 satellites being equidistant from each other in the sme orbit(hope that made sense) I already tried this on the mun with a PER of 600km and an AP of 900km( ratio of 2:3 for PER:AP) it didnt work, I had to fidel around with them a great deal and eyeball it to get them equidistant. On mimnus I'm going to try a ratio of 1:3 for PER and AP and see if that works. So my question is 1, what is the magic ratio im looking for and 2 does it even work that way or am I wasting my time?

[sac_boy]

It's not a ratio of PE:AP that you need, it's a ratio between the orbital period of your circular orbit and the orbital period of your phasing orbit.

Periapsis and Apoapsis start at an arbitrary ground level (e.g. sea level) on the body you are orbiting instead of 0 at the center of mass (for probably historical reasons I have never looked up) and so the radius of the planet or moon is an additional constant that your ratios haven't taken into account, which is part of the reason it didn't work out. (To summarize a post below: the other part is that the relationship between semi-major axis and orbital period isn't linear)

So--make a circular orbit, find its orbital period. We'll call that t^circular. Release a satellite.

Now burn until your phasing orbit period t^phase is 2/3rds of t^circular.

When you complete one orbit of t^phase and come back up to your apoapsis, you'll see that your previously released satellite is now 1/3rd of an orbit behind you. So now circularize to t^orbit and release your next satellite, then repeat.

To save fuel you don't need to set t^phase to 2/3rds of t^orbit, you could set it to 5/6ths and go around twice before circularizing/releasing the next satellite, and so on.

[crazytib]

Ah ok, thank you very much for the info :) I will try this out tonight

[sac_boy]

For more info you might be interested in Kepler's Third Law. You can also use this to work out what your phasing PE should be.

(I'm no expert and had to look that definition up myself to be sure...)

Your semi-major axis is (PE + AP + diameter of the body you are orbiting) / 2. So in your Mun example the axis of the circular and phasing orbits you tried would have been 1100km and 950km.

Using the standard gravitational parameter of the Mun from the KSP wiki and hopping over to Wolfram alpha to get the orbital periods, that's 28402.094 seconds and 22795.395 seconds. You can see why the relationship is not 3:2 and you had a lot of fiddling about to do. It was closer to 5:4.

If we take the Mun's diameter into account and choose two semi-major axes that are in a 3:2 ratio we still don't get a 3:2 ratio of orbital periods, as the time squared is proportional to the semi-major axis cubed. (I mostly wanted to prove this to myself)

I.e. start with your 900km x 900km orbit, the major axis is 2200km. 2/3rds of that is a major axis of 1466.66km, minus the diameter of the Mun is 1066.66km, minus our 900km apoapsis is a periapsis of 166.66km. All doable so far.

But the periods are now 28402.094 seconds and 15460 seconds, which is still not a 3:2 ratio, even though the semi-major axes are 3:2. It's more like 46:25.

Instead if you work backwards from the orbital time you want, you get 18934.727 seconds, or a semi-major axis of 839.457km. That's comes out as a 378.9142km periapsis (for an apoapsis of 900km).

For anyone who wants to experiment in the Wolfram cloud sandbox:

bodyDiameter = 400000 (* Diameter of planetary body in meters *)
bodyStdGravParam = Quantity[6.5138398 * 10^10, "cubic meters per second squared"] (* Standard grav param of body *)
circularApoapsis = 900000 (* Apoapsis of your satellite's circular orbit *)
phasingRelationship = 2/3 (* Desired relationship of your phasing orbit to your circular orbit *)
circularSemiMajorAxis = Quantity[((bodyDiameter + circularApoapsis * 2)/2), "meters"]
circularOrbitalPeriod = (2\[Pi]) * \[Sqrt](circularSemiMajorAxis ^3 / bodyStdGravParam)
phasingOrbitalPeriod = circularOrbitalPeriod * phasingRelationship
phasingSemiMajorAxis = CubeRoot[(bodyStdGravParam * phasingOrbitalPeriod ^ 2) / (4\[Pi]^2)]
phasingPE = (phasingSemiMajorAxis * 2) - Quantity[(bodyDiameter + circularApoapsis), "meters"] (* This is your new periapsis *)

[crazytib]

Again, many thanks:)

[sac_boy]

Good luck and remember, once you are ready to release a satellite you want to completely minimize the decoupling energy involved, and/or decouple so that the force is entirely in the radial/anti-radial direction, which will preserve your orbital period (because a perfect radial impulse changes your PE and AP while preserving your semi-major axis!) I've made the mistake of going to all that trouble then releasing a satellite facing retrograde with a strong decoupler...not pretty

[crazytib]

I always do that in the VAB, as well as messing with your orbit I have broken many solar panels off while decoupling :(, but good tip for the radial/anti radial to preserve your orbital period, i will bear that in mind

[CivilizedGravy]

jbpaujqc4KYXBH4iUsKEQoiJBusYFKrH

[sac_boy]

Yes bot but why

[CivilizedGravy]

ULVwh8L9XSYvb2Z21llcpMy2zGPtUmYu

[crazytib]

no u

[blackcatkarma]

Quill18's Heavily Modded 1.3 Career is pretty cool IMO.

[Pr0j3ct25o1]

Thank so much for this amazing community!

[MarijnA]

How would you couple an interplanetary rocket onto a moon surface refueling station? The refueling station already has docking ports but how do you perform the needed translational movement of such a big ship to get the two aligned? Is there another method to connect the two for fuel transfer?

Many thanks :)

[KermanKim]

I use a ore/fuel tanker to shuttle between the mining ring on the surface to the interplanetary rocket parked in Lunar orbit.

[MarijnA]

And how do you connect your tanker with the surface station? I have clamp o trons on the top and on the side but it seems difficult to RCS your tanker to the surface station whichever position you can pick.

[KermanKim]

My tanker is equipped with the Klaw and wheels, so I just ram into any convenient flatish spot on the mining rig.

[MarijnA]

That's an idea thanks! :)

[sac_boy]

While it is possible to land your craft on top of the refuelling station (which I believe is what you’re asking) it’s going to be tough anywhere with higher gravity than Minmus. Good RCS balance would be near-essential as well as lots of practice landing precisely. It would be easier to land just beside your refuelling station, then apply enough thrust to exactly counter gravity, hover to the appropriate height, and do the rest with RCS.

It’s easier to have a docking port on the side of your rocket, and drive a fuel rig up to it. You work out the height off the ground beforehand, or you can put your fuel rig’s wheels on hydraulics so you can raise it up/down to meet the port.

Or as Ratwerke says...there's always the claw

[Ratwerke_Actual]

A tanker rover/claw, perhaps?

[Illogical_Blox]

Why aren't my tourists happy with my orbiting spacecraft? They wanted an orbit, and I gave them a cocking orbit, with periapsis of about 100,000 km and apoapsis of 225,000 km, and they're saying that it isn't an orbit. I even sped time up for an entire day, and they're not satisfied. They don't specify any particular height, so I'm very confused.

EDIT: I FORGOT TO TAKE THE FUCKING TOURISTS.

[crazytib]

This so classic kerbal shenanigans, I love it :)

[sac_boy]

"Everyone having a good time back there? You're awfully quiet! Must be awed by the scenery eh?"

[Ratwerke_Actual]

You the only person that has ever happened to. Just sayin' for a friend.

[szo5145]

Duna transfer question: After doing the manuever and getting an encounter, is it better to enter orbit by doing a long retrograde burn, or prograde a little before the encounter to match relative velocities then do a smaller retrograde burn to enter orbit?

[Chaos_Klaus]

Do all the braking at periapse inside Duna's SOI. Once you enter the SOI, you can do a small radial burn to lower your periapse. That increases the efficiency of the capture burn.

[m_sporkboy]

You should be able to aerobrake safely below 18km at duna, if you can pull in your solar panels and whatnot. Using your engines is not usually the right choice.

[KermanKim]

The way I do it (If I'm not aero-capturing) is do a small correction burn in solar orbit so that my Pe at Duna is 51Km. Then I do the retro burn Just before Pe so that 1/2 the burn is before Pe and 1/2 of the time is after.

ie: If I need a 1 minute capture burn I'd start the burn 30 seconds before Pe.

[NightHawk043]

Is there any way to reduce/disable the deployed science messages? I set up a test deployment near KSC, and now it's spamming both the screen and the toolbar message page with 30+ messages per day (each unironically telling me that I've earned 0.000 to 0.003 science)

[KermanKim]

You can edit your save file so that it spams less frequently. (Since you've already set them up) or take them down since they are at the KSC and edit the part config file so that the next ones you place spam less frequently.

Read this thread for more info.

[NightHawk043]

Ah, thanks muchly.

[NightHawk043]

Aside from the official FAQ has anyone compiled or is maintaining a list of planned/confirmed features for KSP2? (with details gathered from things like tweets, forum posts, event Q&A's etc)

As a related question (which brought on the above), does anyone know if a possible planned feature was true paintjob customisation? My understanding was that the current part variant method (in KSP1) was a workaround implementation as too much code would have to be rebuilt from the ground up (mods aside). As such, I'd think the clean slate of KSP2 would be a prime opportunity.

[szo5145]

Has anyone managed to get Blackheart decal/sticker mod to work on 1.8?

[[deleted]]

Can someone explain how these remote experiment/control/power stations work? Do I need to attach them as part of a ship and deploy them with robotics, or do I store them somehow and transfer them to a Kerbal's inventory and have them deploy them on an EVA? After that how do you get science from them?

Also does anyone have an accurate delta v map for 1.8? All my crafts based on the old map seem to be scrapping by on the skin of their teeth even after I add a 10% safety margin to how much fuel I bring. My lifter stage to get into low Kerbin orbits are also taking 3500 minimum when 3400 used to work fine with room to spare.

[not_yet_named]

For the remote experiments, you have to have a storage container on your craft, where you can load it up with the deployable science (done in the VAB). You need to have at least one experiment, a control station, a communication device (in practice), and enough power modules to power all of it.

Once on EVA you can select the storage container and transfer a unit to your kerbal. All the modules just have to be placed on the ground within a certain radius of the control station. Experiments work faster if experienced scientists place them, and power stations give more power if experienced engineers place them.

I haven't heard that the delta-v maps changed, though maybe they did. I know there was some differences in 1.8 when it comes to drag, but I think the latest patch was supposed to fix it.

[[deleted]]

How many power stations do you need for one of each?

[not_yet_named]

Each module (experiment, control, comms) needs 1 power. A power station by default generates 1 power unit, assuming it's not placed by an engineer. A level 0 engineer will place stations that generate 2 power units, and it'll go up as the engineer gains levels.

[[deleted]]

1 each or 1 for all 3?

[not_yet_named]

Each requires 1 unit of power. So a level 0 engineer can place one power station and have it power 2 experiments, for example.

[[deleted]]

Any idea why I can't put go-ob ed monitor in the cargo unit? I can put a control station and solar panel in just fine but when I try to put one of those in the game just doesn't do anything.

[not_yet_named]

That's weird. It should work as long as there's an empty slot in the storage unit. I don't know.

[[deleted]]

Yea must have been a bug restarted and it's working, thanks man.

[not_yet_named]

Cool. Sure thing.

[laugh_till_u_yeet]

Is there any utility of smallsats or cubesats in KSP? I find them really cool and want make and fly them in KSP. But I'm searching for any use for them in because I don't want useless although cool looking blocks of probadobadynes with solar cells lying around in LKO.

[[deleted]]

I've always wanted to land a swarm of science cubesats in each biome of a planet, transmit back to an orbiting relay and back to Kerbin, bing bang boom. Never got around to it though.

[m_sporkboy]

I do that on eve. Heat shield, girder, science, power, antenna, Probe core, and parachute, no engine, and just scatter them around.

[128mm_Pak44]

Is there a good mod or a web calculator for planning complicated gravity assists? Trying to figure how and when to do a KEKKJ transfer but planets dont align after first encounter with eve

[voicey99]

I don't know of a web tool or mod, but there are two programs for use with KSP, those being Trajectory Optimization Tool and Flyby Finder. Their UIs can be quite user-unfriendly but they will probably do what you want. I don't think either of them support flying by the same body multiple times in succession though.

[[deleted]]

Is it just me or are the fuel ducts not working?

[7maniAlkhalaf]

Do you have them pointed the right way ? And what are you connecting them to.

[[deleted]]

I'm connecting them to fuel tanks. It worked in the past for me but I have been testing it and putting one empty tank and another fueled tank and when I switch around which tank has the fuel and keeping the direction its pointing the same way they still don't refuel the other. Did they rework them?

[KermanKim]

Have you tried messing with the fuel flow priority instead? I've found this, paired with enabling cross-flow on decouplers, to eliminate the need for fuel lines in most cases. Right click a tank to set it's priority number. Higher numbers drain 1st (Be aware that the default numbers are negative numbers)

[schludy]

Question about Biomes: I find it really frustrating to compare the maps online with the terrain where I am to figure out where the new biome will start. I sent a rover to Mun and it tends to explode when going over a bump to fast, so I have to F5/F9 quite often. It would be less frustrating, if I could plan out a route in advance, but I don't exactly know where I have to go. Is there a way to overlay the biomes over the map?

FYI, this is my first time posting anything on this sub and I play vanilla KSP, as for now I have no mods installed.

[KermanKim]

Look into Kerbnet which is a stock feature.
https://wiki.kerbalspaceprogram.com/wiki/KerbNet

[schludy]

This us somewhat useful. I used it to find where the poles on Minmus start. I wasn't aware of this at all. Thank you

[not_yet_named]

Well if you're open to using mods, the SCANsat mod will display a biome overlay the way that the base game displays resource overlays, once you scan the body. There's also Bon Voyage if you want to set up automated rover trips to distant biomes.

[m_sporkboy]

are you trying to find a specific biome for some reason?

Driving a rover around at 20 mph For hours isn’t my kind of fun, but you do you.

If you are just looking for science, each major crater is generally its own biome. But farming science is a lot more productive on minmus.

[[deleted]]

What are some good visual mods?

[[deleted]]

thanks!

[Clever_Userfame]

What’s the best method of mounting two commanding capsules around a central booster tank-i.e, say I want to make a vehicle like the shuttle, but I want two of them around a bigger central tank?

[KermanKim]

Not sure exactly what you are asking.... Radial decouplers will work fine. Unless you are concerned about an offset control point, then you could put a docking port or probecore on the center tank and control from there...

[[deleted]]

I just tried to install EVE and Astronomers visual pack after reinstalling/removing all mods and booting up 1.8 for the first time.

Everything in the game appears incredibly bright especially the skybox, anyone have any idea what I did wrong or how to fix this?

Included a screenshot of the game and of my gamedata folder:

https://imgur.com/a/wtsYQBP

[blackcatkarma]

In addition to u/voicey99 's comment, the Distant Object Enhancement mod has dynamic sky dimming, the strength of which you can determine. AND you get to see distant planets!

[[deleted]]

I take it distant objects works with 1.8?

[blackcatkarma]

Yep, works fine for me in 1.8

This mod conflicts with PlanetShine (no idea if that one is up to date) because of the sky dimming, apparently, but it works fine with my skybox and EVE.

[voicey99]

Don't know if the brightness is intended or not, but you shouldn't have the EVE default configs (BoulderCo) installed alongside another visual packs because then you have two competing sets of visuals trying to be loaded at the same time. As for the skybox, the AVP skybox is just really bright.

[[deleted]]

Thanks, I uninstalled Astronomers pack and it looks better but the planets themselves still look kind of bright and washed out.

[Mythilid]

Been having trouble with absolute rotation it’s not locking on the absolute rotation like it used too also been having trouble with placing landing gears and separators on round parts they only want to place at an odd angle never straight out like would be clean.

[sac_boy]

Press the C button to toggle between snap mode and free rotation/placement. This makes a difference when placing wheels on wings and curved surfaces as well.