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Fairings does anyone use them


Nich
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I have tired using them a couple times in my normal career and have found that they neither add stability or drag reduction and always reduce the energy of my first stage (by adding weight to lift off the ground). Maybe I am just not using them right.

Please enlighten me

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I also find them largely useless, except for aesthetics. They are so marginal that I originally thought they must weigh like 10 times what they should. So l looked around for real-life fairing weights and found that they are actually only about 2 times too heavy. Fairing should probably help if you had something that looked like a brick instead of a cylinder, or something very asymmetric; but otherwise they seem somewhere between break-even and somewhat inefficient.

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Ditto. Your payload needs to be egregiously draggy before farings are a net gain. If dynamic pressure was a concern they could be useful, but as is you are better off flying subsonic to 35 km than add a faring for 90% of cases.

Anything asymmetric enough for a faring is too large for one. Once again the weight will trump the streamlining.

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I made a ModuleManager config to cut the masses of the bases down to the same mass as their respective decopulers (In all cases they're much heavier). I left the fairings themselves alone, though could be convinced to cut their masses as well.

With just that simple change, it's almost always obvious from a dV perspective to use fairings now, and correctly used fairings also help punch through that scary Mach-1 region.

I have yet to test poorly-made (spherical, or cylinder shaped instead of conical on top) fairings compared to well-made fairings. I'd be curious how much that hurts.

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I have tired using them a couple times in my normal career and have found that they neither add stability or drag reduction and always reduce the energy of my first stage (by adding weight to lift off the ground). Maybe I am just not using them right.

Please enlighten me

I only use them when I have no practical choice. A lot of it depends on the mission and the design.

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I actually just ran 3 tests of my "OTTO" ship (Orange Tank To Orbit, using a simple SLS single stage launch system) I made 3 ships, OTTO-1 had no fairing. OTTO-2 had a fairing shaped like a cylinder, just wrapping around the orange tank. OTTO-3 had a nice pretty pointy fairing that was larger and therefore heavier.

OTTO-1 (no fairing) did the best. OTTO-3 did the worst but was MUCH easier to fly.

OTTO-1 (no fairing) 3653dV in VAB, 318dV left in 80x80 orbit.

OTTO-2 (cylinder fairing) 3518dV in VAB, 225dV left in 80x80 orbit.

OTTO-3 (conical fairing) 3485dV in VAB, 217 dV left in 80x80 orbit

...and this was with my modified fairing bases that are lighter than stock... :/

EDIT: Here are the 3 ships so you can build them yourself to play around:

OTTO-1-2-3.jpg

(Note: My fairings don't have the stock texture. I took the interior texture from Procedural Fairings)

Edited by 5thHorseman
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I think the most important thing is to make your fairings into some lower stages, so that it covers enough atmospheric flight, while the added mass is negligible because of heavy low stages. It's often better to fairing more stuff because they deploy earlier and thrown away earlier!

btw, you definitely need a fairing for this one:

iFVkwRs.jpg

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I can honestly say there are only two reasons I use fairings.

1. My build is absurd, they do help with the stability (could be in my head, but I swear its easier to launch the ridiculous contraption with fairings than without).

2. They kinda look purdy.

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Oh so that's why they're useless. It's not the fault of the fairings, but the aerodynamics.

As always, if y'want more realistic aerodynamics, Ferram is happy to provide them.

Even in stock, the fairings do achieve what they're supposed to be for: they protect fragile payloads from destruction during a hot/fast ascent. The point that this is rarely necessary is more down to the low-intensity nature of stock heating than anything else (as well as the low ÃŽâ€V requirements of LKO permitting inefficient-but-safe steep ascents).

Given the level of squealing recently on the forums about the "impossibility" of flying even in the kindergarten-simple new stock aero, I can understand why Squad is keeping aero failures and reentry heating as unthreatening as they are.

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Did some tests on the OTTOs, jettisoning fairings at 23km, and using Procedural Fairings.

MechJeb ascent to 80km orbit, AOA limit to 5 degrees, 40% ascent path, 100m/s / 1km automatic altitude turn.

Using stock fairings:

OTTO-1: 3663 m/s delta-V in VAB, 339 m/s delta-V in orbit.

OTTO-2: 3531 m/s delta-V in VAB, 311 m/s delta-V in orbit.

OTTO-3: 3511 m/s delta-V in VAB, 385 m/s delta-V in orbit.

Using Procedural fairings:

OTTO-4 (Egg-Shaped Fairing): 3625 m/s delta-V in VAB, 425 m/s delta-V in orbit.

OTTO-5 (Conical Fairing): 3626 m/s delta-V in VAB, 446 m/s delta-V in orbit.

So with FAR, of the stock options the pointy fairing wins. Procedural fairings are better still, with the conical fairing being best (for this long and narrow payload). Both procedural fairings used auto-shape and auto-strut. I used a 2.5m fairing base ring. Even without FAR I'd expect somewhat better results for fairings if you don't hang on to them all the way to orbit.

Edited by SAI Peregrinus
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Even without FAR I'd expect somewhat better results for fairings if you don't hang on to them all the way to orbit.

So far (*oOo*) in stock I have not been able to eject a fairing below 30km without the pieces causing rapid unplanned disassembly of the lifter. I do favor high TWR rocket designs, so they are going at a good clip by that point.

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Only time I found a use for them was to get a small ship on top of a rocket as payload with lots of lifting surfaces into orbit. Without a fairing it dragged the rocket all over the sky.

For their apparent main intended uses of reducing heat and drag: Pretty useless.

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I once made a Rover drop craft to fulfill a contract that needed me to go to 4 different locations on the opposite side of Kerbin. Would love to have some droguechutes on the fairing to make them droppable as capsules to shield a complex craft from reentry aerodynamics. But the current fairing don't allow parts to be attached to it. Any solutions?

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I once made a Rover drop craft to fulfill a contract that needed me to go to 4 different locations on the opposite side of Kerbin. Would love to have some droguechutes on the fairing to make them droppable as capsules to shield a complex craft from reentry aerodynamics. But the current fairing don't allow parts to be attached to it. Any solutions?

[rover, upside down]

[decoupler]

[anything, with chutes on it]

[fairing, covering the above]

[decoupler]

[your rocket]

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One further point: The proper way to use fairings is not to add them after already having built a rocket and a payload. You design the rocket and the fairing as a single aerodynamic shape, and then fit the payload inside the fairing.

In 5thHorseman's example, I would use a 3.75 m fairing base and a fully 3.75 m rocket stack, while retaining the 2.5 m decoupler. This would avoid the additional drag from the "neck" around the fairing base. I would also move the solar panels lower, allowing the fairing to taper off earlier.

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They seem to make a huge difference in my game.

Even with the added weight the performance of the exact same rocket is dramatically increased.

http://www.lacroixdidier.com/temp/KSP_Fairings.jpg

Umm, yes, but that's because the first one without the fairing is not designed that well. Using some streamlined parts like this gets it to an Ap of 296km, nearly twice what you were getting with a fairing...

VMFFolu.png

Edited by Foxster
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For their apparent main intended uses of reducing heat and drag: Pretty useless.

For launching at Kerbin, perhaps. But try aerocapturing a spiky, lumpy probe covered with delicate instruments at Laythe without a fairing, especially if you have to bounce off Jool first.

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Umm, yes, but that's because the first one without the fairing is not designed that well. Using some streamlined parts like this gets it to an Ap of 296km, nearly twice what you were getting with a fairing...

http://i.imgur.com/VMFFolu.png

Indeed but only designing pointy ships,probes,.. is very restrictive without fairings.

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