What is the least useful non-structural part?

[Stargate525]

It's more useful than a lot of parts, it can clean experiments and increase transmission value. If you really want to call science parts useless, call the transmitters useless, they are all functionally the same except for power usage and transmission time, and that really doesn't matter at all.

Hence the tongue-in-cheek comment.

But seriously... I don't see much of a call for it anywhere in the kerbin SOI. Jool, Duna, or Eve are really the only places I would use it.

[Horn Brain]

I hate all those parts.....everytime I tried to build something with the mk3 cockpit it's ended up looking like it's been pieced together with left over bits from a NASA junkyard.

I think mine's pretty slick:

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Everything is perfectly symmetric around the initial center of mass until the jets are fired up after reentry. The two 1.25m rocket tanks are mounted at the center of mass along with all the monopropellant, so draining them doesn't affect the balance. The RCS is perfectly balanced so it's incredibly easy to dock. All the pictures show it docked to a lander that I used when I was doing a fancy Apollo-style mission. It launches vertically and jettisons the two 1.25m tanks (and all the space-specific hardware except the engines) before reentry. Then it uses the two jet engines to make sure it lands at KSC (this was when I was worried about not being able to recover vehicles in career mode that landed far from KSC). In one picture you can see one of three landing legs on the nose. It actually lands on its nose after the chutes deploy (I didn't know that landing gear have no mass, or I would have just used them and some extra wings to glide to a landing).

All the jet fuel comes from the ugly adapters (which look pretty cool in this). It's the only attractive thing I've ever built with the Mk3 cockpit or those adapters.

[BloodyRain2k]

All probe sized parts except the octo core, I hate them. They clutter up my partlist for nothing. Only ones I use if at all are the radial 20kn engines (not the radial Ants). They also make nice LRB seps for deorbiting stages with leftover fuel.

I hate them even more for needing to be unlocked so I can get my loved 1m stack probe core : (

I really want a part filtering feature where I can just hide parts. (I know part catalog(ue?) can do that but there you have to remove them from numerous categories for EACH filter, which is just as annoying)

[CattyNebulart]

Yep, I'll vote for this one as well. Although I did use it once in career mode to get just the amount of TWR I needed. But that's only once during the thousands of rockets I've build.

I use them occasionaly for the core of my asperagoes staging when the remaining mainsials do not provide enough thrust by themselves. It's easier to add 6 or so of these than rebuild a major rocket stack. Also they greatly enhance control due to their good gimballing. And their ISP is not too bad.

[FenrirWolf]

Or the toroidal fuel tank. I've never used that, ever.

Toroidal fuel tanks are the easiest way to make your ship all sci-fi and awesome looking. When stacked up they look more like big ol' bundles of wires or something and it's sweet.

[The Ideal Gas Lawyer]

I echo the other people IIT who point out the utility of the large radial engine. It's a crap engine once in orbit but for getting off the pad or landing those very large base parts on other bodies it can be great. Also adding some much thrust to the core of an asparagus rocket for use after all the rest of the stalks drop off. I used to use the HOME radial aerospikes for that but I realized they're quite OP.

For most useless non structural part, most of the one's I'd pick have been said already. The cased solar panels, advanced canards, shielded docking ports etc. I only realized recently that the old ASAS module was useless for anything other than a craft with nothing but an external command seat. I suppose it is useful for that though

[Merinsan]

Ok, I've read all the posts so far, and I can't believe the ion engine has not been mentioned.

The thrust is so ridiculously low, anything you use it on takes hours to do anything useful.

[Hodo]

For me, the basic jet engine.

I don't have one application that uses it.

[gre8]

Any of the space plane parts. I find them ugly and they hardly match with anything else in order to build nice streamlined space planes. The wings wobble all over the place and the fact that the MK3 tanks only carry ridiculous amounts of Jet fuel makes them the least used parts by me. I rely completely on B9 for space planes.

[Spatzimaus]

Ok, I've read all the posts so far, and I can't believe the ion engine has not been mentioned.

The thrust is so ridiculously low, anything you use it on takes hours to do anything useful.

If you make a small probe, say 1-1.5 tons, the burn times are often only 10-15 minutes (for each of the phases of the flight), and with full physics acceleration you're down to a few minutes. This is, by far, the best engine for light probes intended to map out other planets/moons; you can get one to any Joolian moon straight from low Kerbin orbit. (Mapping requires mods, like ISA MapSat, SCANsat, or Kethane.) Also, unmanned probes for Jool/Eve atmosphere diving in the early game, which nets you a LOT of science.

And ions are useful on larger designs as well. I've got a 34-ton spaceplane with two ion engine pods on the wingtips. Those ions give me an extra 5000m/s of delta-V, which means I can go straight to Laythe from low Kerbin orbit. Sure, the burns might take four or five hours, but switch to x4 physics acceleration and do something else for an hour. And those pods, and their associated xenon, only mass under 2 tons, so they're not really interfering with the plane's performance in other areas.

[Pockrtplanesairways]

Why do you people think the mark 55 is useless?!? it is probably one of the MOST useful engines. for landing its more useful than the POODLE! You think its useless?

Edited February 11, 2014 by Specialist290
Cleaning up a bit...

[gdnoz]

Definitely the Inline Advanced Stabilizer.

What he/she said.

[problemecium]

Exactly what the above says ^

Ever since they made all pods have SAS, it's had literally no function at all and I've never used it even once. I'd been hoping they'd fix it sometime by maybe giving it more torque, but alas.

[The Destroyer]

The big radial engine isn't useless in my opinion, I use it on my large mid-career rockets to get a better TWR.

...Other than that, it is useless.

[m4rt14n]

For me, the basic jet engine.

I don't have one application that uses it.

Basic Jet engine is useful for VTOL. Strap 1-2 underneath a plane and take off.

[Rodyle]

Any part which matches the MK3 cockpit. I tried for a long time to make something out of them, but the irregular shape just confuses the SPH/VAB, and the center of mass is horrible as well.

[BadRocketsCo.]

I would vote for ion engines, since they take a huge ammount of power for their uberlow thrust. Never used them. The big white radial engines are kinda good for my Duna lader.These give me around 600 m/s of Delta-V in Dunas atmosphere.

[Captain Sierra]

I would vote for ion engines, since they take a huge ammount of power for their uberlow thrust. Never used them. The big white radial engines are kinda good for my Duna lader.These give me around 600 m/s of Delta-V in Dunas atmosphere.

If ion engines are useless to you, then it has to do with user error. Even though their thrust was reduced by 75% in .23, they still have uses, and powering them isn't that hard if you know how.

[theend3r]

Yeah it has good Thrust, but the ISP on it is TRASH, it's like using a mainsail for interplanetary travel, it's incredibly inefficient. And the vectoring really only matters if you are building big, but at that point you would use the poodle, or if you are patient, an LV-N.

It has the best ISP of all the radial engines...

[UmbralRaptor]

IEven though [ion engine] thrust was reduced by 75% in .23

Er? Hasn't it been 0.5 kN since they were added?

It has the best ISP[sic] of all the radial engines...

And somewhat more than half the TWR of the 24-77. Using 12x 24-77 will in some cases (<6.5 t payload with an FL-T400, <5.58 t with a rockomaxx -8) get you more ÃŽâ€V than 2x Mk 55. Not than sub-Mainsail Isp is anything to brag about...

[SSSPutnik]

Ion engines are great for probes dropped from a larger ship.

The aircraft parts that have the black heat shielding are useful as jet fuel tanks on Laythe, the small one weighs less than a standard jet fuel tank.

The inline stabilizer is pretty useless but it looks cool, especially stacked next to a decoupler and a battery.

[Adam Novagen]

Sorry, I'm confused about why anyone would call the Inline Advanced Stabilizer useless. The Inline Reaction Wheels are all well and good, but they only use torque to keep your ship locked in position. The IAS (and its larger counterpart, the Advanced S.A.S. Module, Large) will use all available control systems to keep your ship aligned; RCS, wing flaps, thrust vectoring, everything! Understandably that's not always necessary, but it's still bloody useful.

Edited February 11, 2014 by Adam Novagen

[Red Iron Crown]

Sorry, I'm confused about why anyone would call the Inline Advanced Stabilizer useless. The Inline Reaction Wheels are all well and good, but they only use torque to keep your ship locked in position. The IAS (and its larger counterpart, the Advanced S.A.S. Module, Large) will use all available control systems to keep your ship aligned; RCS, wing flaps, thrust vectoring, everything! Understandably that's not always necessary, but it's still bloody useful. You guys do realize this, right?

I think that functionality got moved into command pods a version or two ago. ASAS is deprecated.

[Pockrtplanesairways]

Yeah it has good Thrust, but the ISP on it is TRASH, it's like using a mainsail for interplanetary travel, it's incredibly inefficient. And the vectoring really only matters if you are building big, but at that point you would use the poodle, or if you are patient, an LV-N.

It's not designed for inter planetary travel! it is a landing engine! Use It correctly!

[The Destroyer]

It's not designed for inter planetary travel! it is a landing engine! Use It correctly!

I would rather use 909s or a poodle. They're only good for large rockets that need better TWR and gimbal.

Sorry, I'm confused about why anyone would call the Inline Advanced Stabilizer useless. The Inline Reaction Wheels are all well and good, but they only use torque to keep your ship locked in position. The IAS (and its larger counterpart, the Advanced S.A.S. Module, Large) will use all available control systems to keep your ship aligned; RCS, wing flaps, thrust vectoring, everything! Understandably that's not always necessary, but it's still bloody useful.

In 0.21, the ASAS was built-in to the pods. Now both feature the same thing.