Tricks, hints, and important lessons

[Saaur]

... I'm just wondering how you make that last long rocket stage controllable.

Add a couple radial RCS tanks to your lower stage and add RCS quads to it at both ends. Monopropellant sometimes burns off in a weird order though. Make sure your upper stage RCS tanks are full before decoupling the launch stage.

[Mr Shifty]

Add a couple radial RCS tanks to your lower stage and add RCS quads to it at both ends. Monopropellant sometimes burns off in a weird order though. Make sure your upper stage RCS tanks are full before decoupling the launch stage.

Thanks much! I will try that this evening.

[DMagic]

You can prevent monopropellant from being used by right-clicking on the tank you don't want used and clicking on the little green arrow on the right side (an action group setting for this would be great). This prevents you from draining an upper stage tank prematurely. Just remember to reactivate the tank when you want to use it.

Also keep in mind that you don't need much monopropellant, especially if you don't plan on docking to anything. For non-docking crafts I generally only put a single 100 unit tank, or a few radial tanks, and a single set of RCS thrusters. This is usually enough to keep things going straight during launch and for whatever I need it for once in orbit. And really, if you are using some kind of manned capsule or lander, your upper stage craft might not need any RCS, just drop it off during launch and save yourself from carrying around all that extra mass.

Edited May 31, 2013 by DMagic

[Mr Shifty]

And really, if you are using some kind of manned capsule or lander, your upper stage craft might not need any RCS, just drop it off during launch and save yourself from carrying around all that extra mass.

Good tip. In this case, I had designs on using RCS to soft-land the lander away from the transfer engines, and in fact it was necessary, since I still had about 2 m/s of lateral velocity when I hit Minmas, which broke apart the LV-N engines (as you can see.) I was able to separate the lander and bring it down softly away from the engine debris with RCS. Obviously this only worked because of Minmas's low gravity.

[triffid_hunter]

since I still had about 2 m/s of lateral velocity when I hit Minmas

heh really need that surface retrograde to line up perfectly with the nadir for landings, especially as your vertical speed approaches zero- that's when the shifting retrograde shows you your horizontal velocity the most!

[kookoo_gr]

If your Kerbal is running out of rcs fuel during EVA and is near a command pod, enter it when the Kerbal goes for an EVA the pack will be refueled.

[Procyon]

On asparagus type staging, using mainsails in particular, turn off gimbaling on all outside engines and just use the center engines gimbal for control to improve stability during launch.

[Anglave]

When building ships with radial stages (4x, 6x, 8x) you actually want to build in 2x symmetry. Attach the decoupler, fuel tank, and struts (from the drop stage to the central stage). Then hold alt and click the decoupler to clone the whole drop stage. Repeat as many times as necessary.

Trust me, this will help a lot with fuel routing and strut placement as you progress with your build.

Also, when adding new vertical stages to my rocket, I add one tank to the center column and stitch it on (go from the bottom tank to the next tank up, just across the seam, with 4x symmetry struts). Then alt-click to clone that tank, and with symmetry enabled connect it to the outer stages. Viola, the stitching struts are already in place!

[Dacknanimous]

In vacuum, you can use time-warp to stop a ship from rotating and potentially save RCS fuel and/or time.

That's an exploit, IMO exploits take the fun out of any game or sim. (Basically, a form of cheating)

I really hope they fix that.

[triffid_hunter]

In vacuum, you can use time-warp to stop a ship from rotating and potentially save RCS fuel and/or time.

That's an exploit, IMO exploits take the fun out of any game or sim. (Basically, a form of cheating) I really hope they fix that.

I see that as a workaround for the lack of instrumentation such as MechJeb's Smart A.S.S. and lack of ability to toggle RCS, SAS and ASAS individually.

With Smart A.S.S., the only time I use that trick/cheat is when trying to use RCS to translate and ASAS to maintain a heading, without the ASAS making my ship spaz out by firing all the RCS wildly.

[triffid_hunter]

On asparagus type staging, using mainsails in particular, turn off gimbaling on all outside engines and just use the center engines gimbal for control to improve stability during launch.

hm, I don't disable gimbals on the outer engines, and have great launch stability.. I did try disabling them once and couldn't turn!

[Joe_Bender]

If you end up in LKO (80km or less) and you still have the last lifting stage with you, using four sepatrons pointing backwards will be enough to deorbit that stage when you separate it from your space vehicle.

1. when you build your rocket, place four sepatrons on the final stage of your rocket, down on the lower end next to your motor and face the nozzles upwards. place them in the same staging as the decoupler for that unit.

2. launch into orbit, finalize orbit, and then rotate craft to prograde.

3. stage the tank/motor/sepatrons. they will fire and decrease the speed enough so that the last lifting stage deorbits.

I havent tried this with higher orbits but it may require more sepatrons to get enough of a speed decrease.

[DMagic]

hm, I don't disable gimbals on the outer engines, and have great launch stability.. I did try disabling them once and couldn't turn!

Sometimes you will need the gimbaling once you start turning. I assign the gimbal toggle to an action group for the booster engines, then disable them on launch. But sometimes I have to reactivate them once I start turning, though by that point I usually only have two boosters left so the overall stability of the rocket isn't affected so much.

[triffid_hunter]

If you end up in LKO (80km or less) and you still have the last lifting stage with you, using four sepatrons pointing backwards will be enough to deorbit that stage when you separate it from your space vehicle.

Another way to do this, assuming your lifter has some fuel left, is to put a probe core on your lifter stage. After decoupling payload, shut the engine down, point retrograde, put throttle to max, reactivate engine then switch back to your payload.

Make sure you're not pointing prograde when you decouple or you'll torch your payload with engine exhaust!

I successfully use this technique from orbits as high as 200km- with a strong engine and fairly empty tanks it's amazing how much dV you can shed while still within physics range

[Stazi]

Another way to do this, assuming your lifter has some fuel left, is to put a probe core on your lifter stage. After decoupling payload, shut the engine down, point retrograde, put throttle to max, reactivate engine then switch back to your payload.

Make sure you're not pointing prograde when you decouple or you'll torch your payload with engine exhaust!

I successfully use this technique from orbits as high as 200km- with a strong engine and fairly empty tanks it's amazing how much dV you can shed while still within physics range

Since 0.20 I've been playing with debris enabled, and I've been placing a probe core in all my orbiter stages to help reduce clutter by burning them retrograde once I release the payload.

You can even use the payload engines to give a small push to the orbiter stage to help shed some of its velocity before attempting to de-orbit it.