Is rcs enough in space?

[Rockyfelle185]

I have a space station and plan on bringing up some parts to it, prefferebly multiple at once, my plan was to bring 4 parts up with one rocket, catch up with the space station, drop all 4 station parts, crash my rocket, and then dock up with all the parts using only rcs attached to them,mwill this work?

[blizzy78]

I'd suggest you try and see for yourself what you can do with using only RCS. It's quite capable.

[Rockyfelle185]

Well the thing is ita kinda hard for me to get into orbit, and I dont want to realise my mistales when its too late, therefore i, asking the ones who knows

[blizzy78]

Embrace failure, it is essential to learning.

[Rage097]

RCS will most likely not get you into Orbit. For docking however, it's almost completely essential.

[capi3101]

It should work. The trick of course is going to be placing the RCS thruster blocks in the right spot to give you good overall steerage. 12 blocks is what I recommend per station bit - 4 as close to the top as you can manage, 4 as close to the bottom, and four along the center of mass. Preferably all twelve blocks should be placed the same radial distance from the central axis of your station bit to avoid uneven torque when rotating (you can mount an RCS block on cubic octagonal struts or even girders if necessary). RCS fuel tanks will also be needed, of course. RCS makes docking a heckuva lot easier (largely because of the H and N keys; you don't have to turn the whole assembly around to speed up or slow down).

I would recommend using bipropellant (standard engines) for getting to the rendezvous point, and using RCS for the actual docking maneuver. You can use RCS for both, but it takes a LOT longer to get a rendezvous.

[BostLabs]

If you are going to just drop off your station parts then deorbit your rocket, then make sure your station parts have some form of control pod on them. Otherwise you may find that you cannot control them.

Personally, I use the final stage of my rocket to dock the station parts then uncouple from the station part then deorbit.

[Wallace]

Depending on how heavy the parts are, you should be able to move them about in orbit just fine, if you match velocity within say 500m of the station then you should be just fine bringing it all in with just RCS. just so long as you have enough monopropellant for the size of the parts.

Personally I would use a small tug with plenty of RCS and reaction wheels that you can then throw away after so you don't have all the extra parts of Monopropellant tanks and RCS blocks all over the station when you won't really need them after the building is done.

Edited October 8, 2013 by Wallace

[Hodo]

My station in orbit around Kerbin has a tug that is only RCS thrusters, and RCS tanks. I use it to move massive Jumbo-64 (the orange) tanks around. I have even used it to catch a SSTO that was at a 20km lower orbit and bring it up to my station. RCS thrusters are pretty good, not real efficient but good.

My only other suggestion besides what Wallace said, is either add a generator, or solar panels because RCS thrusters generate no electricity, and you don't want to run out of power.

[Starwhip]

If you plan on actually docking two objects in space, RCS is vital. Make sure you have quite a bit, because if you run out on an unmanned craft you can deem yourself screwed.

[Decent Weasel]

Looks like I'm going to be the lone dissenting voice here.

First, I'm assuming you're already close to your target vessel.

In my experience, with proper targeting (control both ships from their docking ports, and ensure each ship has the other ship's port targeted) you can generally dock pretty well without RCS. I like to let Smart A.S.S. do the pointing, but that's just laziness on my part - you've simply got to point toward the purple orb.

Move toward your target slowly, around, I dunno, 3m/s. Then, as you're just about to touch the other ship, throttle up a couple notches to exert a constant push. You don't want to smash into your target vessel, but once you get close, you've gotta mash 'em together to make sure they stick instead of just bouncing.

So yeah, you can do it without RCS. It may be easier with it, though. Mostly I avoid RCS because I don't like the weight penalty.

If you don't take RCS, you need an SAS module on each ship and an engine that can push at least one of the ships 'forward' with respect to the docking port. (That's the only way I can think of to reliably mash the ships together when they make contact.)

Edited October 8, 2013 by Decent Weasel

[SRV Ron]

Docking efficiently is a process that will take a while using small maneuvers to first match orbit, then to ease the item into place. Get a feel with a test vehicle, in thus case, a big orange fuel can with a pair of RCS thrusters mounted balance so they did lateral movements without introducing unwanted rotation when the SAS is off. Like real life, such maneuvering takes time and patience.

In this example is the fuel can and the last stage that placed it into orbit. One can practice docking by moving this 42 ton object around with thrusters. A lot different from maneuvering small probes with thrusters. Bump the booster, which has no RCS or other controls, and it is going to start slowly spinning.

This is an example of two ships that I got to intercept then match orbits. A much harder job since the ship I was maneuvering didn't have balanced lateral thruster capability that would be needed for docking.

Edited October 9, 2013 by SRV Ron

[rosenkranz]

Docking without RCS isn't all that hard until you're station gets over 200 parts. After that the lag can make doing this very frustrating.

On the other hand, RCS can easily be over done. The more rcs blocks you use, the faster you'll go through monoprop. Placement is everything. I strongly recommend the RCS Builder's Aid mod http://kerbalspaceprogram.com/rcs-build-aid-v0-2/

I can usually get away with just 4 RCS blocks about the CoM on even 100t segments. If I use the stock-alike 3-axis or the B9 3-axis blocks and I can get away with just 2 about the CoM.

Minimal RCS means you need less monoprop. Two of the 40L radial tanks or a 100L stack tank is enough for the smaller segments (<70 ton). For 70-150 ton segments, two of the 150L radials or 100L stack tanks should be enough. It also keeps the part count down.

However, it does require more patients as docking will take longer.

If you don't mind mods, i'd strongly recommend romfarer's docking cam. Being able to see what the heck you're doing makes docking so much more intuitive. http://kerbalspaceprogram.com/lazor-docking-cam/

If romfarer is too much, there is also http://kerbalspaceprogram.com/dock-align-indicator/

Just my 2 krones

[Rockyfelle185]

Damn, thanks all of you, 12 replies is just amazing My plan now is going up with a rocket carrying 4 parts, 2 identical on each other opposites sides, so it wont get unbalanced.

All parts will have as many rcs thrusters that I sees fit, probably what the guy in the beggining said, it will also have a "steel part" with some rcs tanks on and will be connected via decoupler to the part.

Once I get into orbit I will catch up with my station, drop every part and go away with my rocket to infinity, I will use the rcs on each part to dock with the station, and then I will decopule the rcs tank, and repeat until all parts are there.

How does my idea sound? Ive planned it all on your suggestions, I wont use a mod though.

And 1 more question, is there a good way to "explode" a part in space, cause I dont want the empty rcs tanks just flowing around

[KSK]

Just a quick question to those folks using tugs - how do you balance out your RCS to cope with tug or tug+cargo? I've thought about using them but could never quite see how it would work.

[sal_vager]

Fine control mode (capslock) will try to balance your RCS for you, it's not 100% though.

Also, try more reaction wheels

[RuBisCO]

RCS will most likely not get you into Orbit. For docking however, it's almost completely essential.

Bull****

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Edited October 10, 2013 by RuBisCO

[Alistone]

Just a quick question to those folks using tugs - how do you balance out your RCS to cope with tug or tug+cargo? I've thought about using them but could never quite see how it would work.

I use a 3 man capsule for strong reaction wheels. I let the reaction wheels adjust/maintain the orientation. Just put the RCS as close to the center as possible since it is used primarily for translation you can reduce rotation by keeping it tight in and use less RCS ports to make sure the RCS rotation force doesn't overpower your reaction wheels. Makes your translations and rotations slower, but slow is definitely better than fast when you're trying to dock.