how do you do torque in MkII spaceplanes?

[Cirocco]

Hi guys,

after the release of 0.25 (yay!) I was messing around with the new spaceplane parts, trying to make a spaceplane with exclusively MkII parts and I ran into a bit of an annoying problem: I couldn't put any real torque near the center of mass. I love the fact that we now have LFO MkII tanks, but now I was faced with the fact that we don't have any MkII-shaped reaction wheels (other than the probe core maybe?).

So I was wondering, how do you guys ensure you have enough torque on your spaceplanes to manouver in the vacuum of space? Do you just rely on the cockpit reaction wheels? Do you add the regular 1.25m tanks with their respective reaction wheels? Do you rely purely on RCS thrusters? Do you have another inventive solution? Please share!

[Geschosskopf]

The Mk2 Probe Core has some torque but mostly pitch, not so much yaw and roll. So what I do is put 1 or more 1.25m reaction wheels in the cargo bay, along with the RTGs to power them.

[Cirocco]

The Mk2 Probe Core has some torque but mostly pitch, not so much yaw and roll. So what I do is put 1 or more 1.25m reaction wheels in the cargo bay, along with the RTGs to power them.

huh, that's a pretty good idea. Might do that in the future.

[Oafman]

If you use the fuel tank which adapts from MKII to MKI placed in front of your cockpit (obviously I mean the cockpit with an attachment node on the front), you can just whack a standard SAS to the front of the plane

[Wanderfound]

Behind an intake or in front of an engine works too.

But, usually, you'll want to include a small cargo bay on all but the smallest spaceplanes just so you have somewhere to stash unaerodynamic bits like solar panels and science instruments and such. An ASAS module and a battery usually make a good mounting point for a couple of solar panels, a mechjeb unit and some TAC-LS containers.

[Alshain]

Yeah, a small cargo bay is the best way to get more SAS, it also works for solar or PB NUKs and monopropellant if your not using the Mk II inline docking port, since the Mk II mono prop tank is pretty much too big for anything unless you plan on using O-10 engines. Also, with all of that, you have just enough room for a KAS toolbox.

Edited October 9, 2014 by Alshain

[LethalDose]

Also, the placement of the reaction wheels doesn't matter, i.e. you don't need to place them near the CoM on your plane, so you have some freedom in where you place a cargo bay to sneak them in.

[Beachernaut]

Can't remember if it's true in KSP or not, but the further the reaction wheel is from COM, the more effect it'll have (within reason). I generally put mine behind the air intake.

[Franklin]

Can't remember if it's true in KSP or not, but the further the reaction wheel is from COM, the more effect it'll have (within reason). I generally put mine behind the air intake.

Yeah, I always understood that you place them like you would RCS blocks.

[SlimeCrusher]

As far as i know you can place reaction wheels anywhere and they'll give you the same torque, it doesn't matter if its 5cm or 5m away from the COM, it will always give the same torque. So yea.

[Claw]

Can't remember if it's true in KSP or not, but the further the reaction wheel is from COM, the more effect it'll have (within reason). I generally put mine behind the air intake.

This is a common misconception that is not true. As Lethal Dose and SlimeCrusher (and others) said above, you can place the torque modules anywhere and the effect the torque has on the ship is the same (regardless of distance to the CoM).

The difference will come in if you put a lot of torque out away from the CoM on wobbly parts. Then the ship may have a tendency to tear itself apart. Although this has more to do with wobbly parts than torque.

Cheers,

-Claw

[James_Eh]

The difference will come in if you put a lot of torque out away from the CoM on wobbly parts. Then the ship may have a tendency to tear itself apart. Although this has more to do with wobbly parts than torque.

Nope, it's all about the torque, not my bad ship design. Stupid torque!

[MockKnizzle]

As anyone who has taken some basic physics or statics will know, the location of an applied torque on a rigid body doesn't matter in the slightest. However, as ships in KSP are collections of elastically-connected rigid bodies, putting your reaction wheels on the ends of long, bendy bits can lead to wobbly-spaghetti syndrome.

As long as your craft is well-strutted, you cans stick your reaction wheels anywhere.

[Red Iron Crown]

Location doesn't matter for torque wheel effectiveness, so I place them as part of making wet and dry centers of mass as close together as possible on spaceplanes.