[[1.12] Other Worlds - A Story and Planet Mod]

This mod looks amazing. Is it compatible with Spectra visual pack?

[name of mod to show collision meshes?]

thank you sir

[name of mod to show collision meshes?]

Can anyone name the mod that allows you to view part collision meshes in VAB for the purpose of making custom bearings such as in Strazenblitz75's spin launcher video? https://www.youtube.com/watch?v=vS74SsBd3eQ&t=670s

I've only found the Collide-o-scope mod, but it hasn't been updated since 1.3. Is there anything newer?

Cheers

 

[[1.12.x] Kerbal Atomics: fancy nuclear engines! (January 22, 2022)]

7 hours ago, Starwaster said:

It's a double edged sword to be sure. H2 is the most efficient propellant, all other factors being equal but yes you will be consuming a lot of it by volume.

Usually though, mass is the main consideration, not volume.  Actual conceptual designs revolving nuclear rockets see a mass reduction by not having to include oxidizer. The H2 tanks can be made lighter as well. (Real Fuels takes lighter H2 tanks into consideration so give that a try if you're not already using it)

All that said, nuclear rockets using ammonia or methane have always been my preference. You'll definitely want RF for that but I'm not sure if  any current mods or configs  offer those propellant choices for nuclear.  Not anymore.

I appreciate this clarification, and it makes sense to me that volume is a better tradeoff over mass. Thank you for your time, my early career is going to need to invest is some large volume tanks smh

[[1.12.x] Kerbal Atomics: fancy nuclear engines! (January 22, 2022)]

Hello all,

I'm new to using Kerbal Atomics and was lured by the prospects of having more atomic engines to play with. However, I am aghast by the amount of LH2 fuel they consume, and I'm thinking to myself that either I have no clue about ISP (rudimentary at best) or I'm experiencing a bug? For example, from a fresh install with only kerbal atomics and restock installed, the "Liberator" engine consumes 726.273 LH2/sec?? What is the use case of such engines? Maybe I'm not thinking large-scale big enough, but even so, conventional rockets would still seem better. I really don't understand this mod, can someone please clarify

 

......eventually, using the ISP formula, I_sp,g0 = F_T / m_fuel   and finding in-game the mass of LH2 ~= 0.0708 kg/unit I confirmed that the expected fuel flow is indeed 726 LH2/sec, but I'm afraid this leaves me just as confused

[[1.9.1 - 1.10.x] Beyond Home 1.5.0 (Supports Parallax)]

New to Beyond Home, and sacré bleu, @Gameslinxthis mod is amazing--truly. I'm 100%, genuinely reinterested and excited to play KSP now. Thank you for your herculean mod.

Also, Principia may not be the only cause of solar panels getting blocked by Destiny as I do not have it, but I am experiencing a similar problem. I do however have a respectfully decent amount of other mods installed.

And if all ya'll are noobs, then I'm a scrub, so let me know if/what details you need to help diagnose.

Cheers!

edit: Specifically, the panels get "blocked by Destiny" once Fate gets within ~10deg from behind Destiny (just inside Destiny's sunflare). Interestingly, the issue also persist when Fate approaches ~10deg from in front of Destiny but only when in 50x or more time warp (orbit Lua); otherwise, or after exiting time warp, the panels are no longer "blocked by Destiny". Intuitively, it feels as though the barycenter is the light source that gets blocked by Destiny when fate sets behind it.

[Mk3 Spaceplane Shuttle Design issues]

Here are some other possible considerations in addition to everyone else's:

Cannot take off -- try lowering the front landing gear so that the aircraft points slightly upward on the runway. This will increase your Angle of Attack. Alternatively, you could slightly angle up your front canards upwards to increase AoA, but this may have adverse affects during flight. In any case make sure your rear landing gear is not too far behind your CoM.

Steer in random direction -- I find that disabling steering on the rear landing gear can also make a difference. If problem persists, it may also be that the plane is too heavy for your landing gear, which will cause them to bend/wobble. Either add more to support the weight (I have some designs where I use two small landing gear side by side) or upgrade size of gear.

Flip over -- CoM/CoL is tricky. How the fuel drains during flight is an important consideration. Try changing the fuel priority so that the fuel in the front of the plane drains last. This will help maintain a forward CoM. Using two short fuel fuselages rather than one long one can also give you better control of the flow.

Spaceplanes are far more difficult to master but much more rewarding once you do! Best of luck.

[Resonant synchronous orbit for repeat Mun landings]

4 hours ago, Zhetaan said:

@rocketBob:

There is an equation, but it is not a pretty one.

Also, inclination is not a problem provided that the orbital period is resonant with the Mun's rotational period.  For example, a circular, Kerbin-synchronous, one-day, polar orbit will still pass over the same longitude once every orbit (that is, once per day).  An equatorial version of the same orbit holds position over that longitude indefinitely.  Intermediate inclinations and eccentricities show greater and greater apparent motion with respect to a surface observer, but so long as the semi-major axis of the orbit remains the same, it also remains synchronous (and the motion will appear periodic ... because it is).

The equation for orbital period is this:

T = 2 * pi * (a³ / GM)^1/2

where:

T = period
a = semi-major axis
GM = gravitational parameter, which for the Mun is 6.5138398×10¹⁰ m³/s²

In your case, the easy solution is to have your T equal to 138984 / n seconds, where n is some integer and 138984 is the Mun's rotational period in seconds.

However, you don't want the period; you want the apoapsis, which means we need to rearrange the equation:

a = (GM * T² / 4 * pi²)^1/3

To simplify this for the Mun, we can pre-calculate a number of the parameters and combine constants:

a = (6.5138398×10¹⁰ * T² / 4 * pi²)^1/3

= (1.649974896×10⁹ * (138984 / n)²)^1/3

= (3.18718×10¹⁹ / n²)^1/3

For n = 1 (a synchronous orbit), the value of a is 3.170556×10⁶ m, which, less the 200,000 m of the Mun's radius, gives a circular orbit at an altitude of 2.9706×10⁶ m.  This cannot be used because the Mun's sphere of influence ends at 2.4296×10⁶ m.

For n = 64, the value of a is 198159.8 m, which puts the orbit under the Mun's surface.  The reason this is undesirable is left as an exercise for Jeb's piloting.

For n = 58, the semi-major axis is 211600.6 m, and that means a circular orbit at 11,600.6 m because such a low orbit is only barely enough to clear the Mun's mountaintops. 

It also means that you will have to wait 58 orbits to get a resonance.  Keep in mind that for all of these values of n, the number of orbits is largely irrelevant; excepting cases of crash or escape, the orbits will add up to one overhead pass of your chosen landing site for every Mun rotation.  The spacecraft will pass over the correct longitude many times--58, to use the maximum safe value--but those passes will also but for one be at the wrong latitude unless the landing site is on the equator.  If the orbit could precess, then it would be possible to achieve your goal a little more often (at the cost of some truly frightening calculations), but precession requires n-body gravity.

To take these values with a fixed Pe and obtain a useful Ap requires one more bit of mathematical wizardry.  The semi-major axis is to an ellipse something like a radius is to a circle, but because it is an ellipse, you can have varying Pe and Ap values that still give the same semi-major axis.  For the Mun, the semi-major axis is:

a = (Ap + Pe + 400000) / 2

where the 400,000 is the Mun's surface diameter and the Ap and Pe are taken as altitudes from the surface (as KSP displays them).  If we hold the periapsis at 15,000 m then the equation simplifies to:

a = (Ap + 415000) / 2

and combining this with the earlier equation gives:

(Ap + 415000) / 2 = (3.18718×10¹⁹ / n²)^1/3

and once rearranged, this gives:

Ap =  2 * (3.18718×10¹⁹ / n²)^1/3 - 415000

This constrains n by quite a bit:  for example, you can no longer go above n = 56 because that lowers the 'apoapsis' to below the periapsis.  You can also no longer go below n = 4 because smaller values of n require either your Ap to be outside the Mun's sphere of influence or your Pe to be above 15 km.

I will assume that your mission profile is such that you will prefer either a long, languorous time at a high Ap or a close-in, near-circular orbit.  For this reason, my suggestions to you are to use either n = 4 or n = 56.

For n = 4 and a Pe of 15000 m, the Ap is 2.101473×10⁶ m.  The orbital period is 34,746 seconds.

For n = 56 and a Pe of 15000 m,  the Ap is 18218 m ... approximately.  The important thing is to make certain that the orbital period is 2481.9 seconds.

Zhetaan, this is exactly what I was looking for. Thank you for taking the time to guide me in this math, and I appreciate the detail that you have provided here. This makes sense to me now, and I am looking forward to being able to apply this knowledge towards other missions! The max/min constraints is especially interesting. Next up is a Minmus refueling station/base, and this immediately strikes me as being super useful for transporting fuel/ore back up to orbit.

I've played around a little with the n value trying to find a good balance between fuel efficiency of a lower apoapsis and time efficiency of a higher one. Ultimately I'm going with your advice of n = 4, which will require about 200m/s to circularize down to 15km. n = 8 for example only saved me about 25m/s, and in the end I'd rather plan for spending more fuel than spending more time up in orbit. Not to mention that at n = 56 time warp would be limited to 10x (yikes).

Thanks again!

[Resonant synchronous orbit for repeat Mun landings]

10 hours ago, Cpt Kerbalkrunch said:

Smarter guys than me can tell you about calculations and whatnot (I fly mostly by feel and experience; I know what I wanna do and how to do it, but not how to explain why it works). Airless worlds are pretty easy, though. If you're in an equatorial orbit, just land your first module where you want. Then set it as your target and drop everything else right next to it. After a while, you'll be able to land within 100 meters consistently. I really enjoy seeing how close I can get without busting a solar panel.

 

Oops. Just realized you said your LZ is above the equator. Still don't think it matters. Once you land that first module and target it, it'll give you the inclination just like any other target. You can adjust at the node like normal. You'll have to be aware of the rotation, though. A little adjustment on the way in. Nothing major.

 

Oh, yeah, and welcome to the forums. Neglecting to say that is frowned upon. 

Thank you for your welcome Captain. Apologies for not having said I am new here. Perhaps I should also mention that I have been Hooked on Kerbal for the past 3 years! It amazes me that this game continually offers new ways to learn.

This is solid advice, and what I have previously done for landings in the past. When landing somewhere above/below the equator, I would put myself in an inclined (usually ~45deg) orbit and wait for the LZ on the body to drift slightly before being under my craft. Once the target was set, it was fairly easy to correct course during the descent using the target markers on the navball. This time however, I was looking to expand my knowledge of the game and learn a more precise/predictable way to get the job done.

Thank you to you and everyone else for the input!

[Resonant synchronous orbit for repeat Mun landings]

Hello

I'm attempting to build a base on the Mun. Each section is parked together in orbit with a lander craft to drop them on the surface. What I would like to achieve is an orbit to facilitate landing the pieces in the same spot. Ideally this orbit would have a periapsis around 15km. How to I calculate the apoapsis in which the craft returns to the same longitude at periapsis every N orbits? The landing site for this base is above the equator, is such an orbit possible with inclination?

Cheers