Any advises for good stable rocket that even Bob and Bill can fly

[Pawelk198604]

The changes from 1.0 make the game very hard for me :-( especially the new aerodynamic model, thus is more realistic than it was before in game, the new specialization of Kerbonauts also not making my life easier but i don't wan change that as

John Fitzgerald Kerman used to say "We choose to go to the Mun. We choose to go to the Mun, in this decade and do the other things, not because they are easy but because they are hard. Because that challenge is one that we are willing to accept. One we are unwilling to postpone, and one we intend to win"

now only kebonauts with pilot skills like Jeb could fly rocket, i already created stable rocket using basic parts that was reliable and stable that i used to put on orbit alone, but i lost my design as easy as NASA lost original Saturn V blueprints i just forgot to back-up the file when i reformat my PC :-(

Now i created rocket that i was able to put Jeb on orbit and i was barely had enough deltaV to deorbit him later on (I could not bear the loss of Jeb, playing without him is not the same)

Could you recommend my good configuration for rocket that not need much stabilization, the rocket that is stable itself.

that's my current rocket:

[Alshain]

That isn't bad but you don't need active winglets or that big of winglets for such a small rocket. Put on the little ones they added in 1.0.2 (small with yellow accents).

Also, you need something on top, a parachute or a nose cone.

You really don't need the extra reaction wheel module, that cockpit has one that should be good enough for that rocket.

Move all your extra gear (Engineer and science stuff) to a service bay to protect it from heat and keep it from causing aerodynamic issues. You should unlock the service bay pretty early in the tech tree.

Your parachute should be in its own stage. Deploying on separation is going to cause it to burn.

Edited September 29, 2015 by Alshain

[Harry Rhodan]

Use angle snap or those winglets will attach slightly off center. Put KER in partless mode so you don't have to carry a single unsymmetrical part around. Use bigger tanks if they are available.

[Pawelk198604]

Your parachute should be in its own stage. Deploying on separation is going to cause it to burn.

Thanks i forgot that,

And i have parachute on top of original design, but i need little stabilization so i put basic sas here and used radial parachute, as for science equipment i heard thay mystery goo is good to put it on top of rocket to secure it from burn up. maybe not as efficiently as services bay, but it make capsule lighter.

[GoSlash27]

pawelk,

The trick to it is to keep the fins and thrust balanced so that it naturally follows a gravity turn. This requires minimal control and is naturally stable.

Fins too far back or too much area = it wants to face plant at low speed and not tip over enough at high speed.

I'll see if I can knock you together a very simple and low tech 2- stager to orbit.

Best,

-Slashy

[Superfluous J]

Nose cone on top for sure. inline parachutes have been shown to have MORE drag than just leaving the node with no attachments.

I agree on the fins. With no pilot you want stability over control.

Disable the fuel tank at the top of your first stage, and have it right clicked and ready during ascent. As soon as that first engine turns off, enable LF and O2 in that top tank. This will keep your rocket top heavy.

I'd be scared to decouple that 2nd stage, as you'll still be pretty low in the atmosphere and back heavy. I suggest maybe beefing up the bottom stage and taking it from the top. Though that's a rough compromise because it'll hurt your eventual dV. You can experiment with fins but they may cause problems with the earlier stages.

[GoSlash27]

pawelk,

It looks like you're at level 4 on the tech tree. Is that correct?

I can get you to orbit at level 2 with starter facilities, but I can't bring the goo pods. Level 4 is no problem.

Here's an easy to fly orbital lifter at lvl. 2

http://wikisend.com/download/506720/early2stager.craft

Here's the lvl.4 version with science:

http://wikisend.com/download/326644/early2stagerlv4.craft

For both of them you keep it vertical to 90 m/sec velocity, then pitch prograde to 80°. After that, just keep the acceleration under 2G and keep the nose prograde.

Best,

-Slashy

Edited September 29, 2015 by GoSlash27

[Coyote27]

GoSlash, is there any particular reason that you put the fins more forward toward the middle of the rocket instead of at the tail? Just curious.

[GoSlash27]

GoSlash, is there any particular reason that you put the fins more forward toward the middle of the rocket instead of at the tail? Just curious.

Coyote27,

Just a matter of balance.

If the fins are too far back it's excessively- stable. Putting them there makes the rocket want to naturally follow a gravity turn.

That's important because the only source of guidance on these rockets is the reaction wheel in the command pod. If you design it to naturally tend to go where you want it to go, you need a lot less command authority. This aids stability when you don't have access to SAS.

Best,

-Slashy

Edited September 30, 2015 by GoSlash27

[Specialist290]

Moving this over to our Gameplay Questions subforum

[Kryxal]

Excessively-stable isn't such a problem, the command pod's enough for an initial turn at maybe 50-100 m/s. I generally like to make a turn a bit earlier, though in that case it's a bit less of a turn.

[GoSlash27]

Kryxal,

Best I can say is that hasn't been my experience. When dealing with non- pilots and no SAS, I've found it helpful to design the booster so that it follows a gravity turn on it's own with minimal input.

YMMV,

-Slashy

[sdj64]

The reason that Jeb and Val can fly your rockets but Bob and Bill can't is that they are pilots, and have SAS ability. To get SAS without a pilot you'll need a probe core (except the Stayputnik) or the pilot assistance nose cone. I forget if you've unlocked those things that early in career but really you don't need to fly Bill or Bob until you've unlocked one of them. Unless Jeb died in a crash.

It's hard to fly a rocket without SAS, especially one with lots of control authority (big fins and extra reaction wheels).

[Pawelk198604]

Thanks for all you advises, Normally I would not care myself, but I wanted to other Kerbals also gain some experience, speaking of which how is the fastest way to boost kerbal skills?

Now i try to create some basic rocket, so you say that small fins are better that the bigger ones?

[Pawelk198604]

What do you think about my rocket?

I want boost my science, and i need for that kerbal with science skills, but they are not real pilot and here is the problem :-(

[mattssheep4]

When you unlock probe cores, they can help a lot with stability, even just the stayputnik or whatever its called.

[Harry Rhodan]

What do you think about my rocket?

That stage in the middle is completely useless, it has an inefficient engine with too much thrust and not enough fuel to make it worthwile. It's dead weight. Ditch it.

And from the video I gather that you like to play with the thrust limiter and that is probably why your uppermost stage has a TWR of around 0.5 while it should actually be around 2 if you didn't fill up the service bay with lead. Tweak that up and use a FL-T400 tank instead of the FL-T-400. Remember that the upper stage has a much more efficient engine that you just can't use in the first stage because its thrust at sea level are horrible.

Edit: Sorry, the sea level TWR of your third stage really is 0.5 with that setup.

But as you'll only use it higher up in the atmosphere its TWR will be above 1 even with the FL-T400.

Edited September 30, 2015 by Harry Rhodan

[GoSlash27]

What do you think about my rocket?

I very rarely use more than 2 stages to orbit. I'll have to review the numbers on it.

*edit*

My quick back- of-the- envelope says you have just barely enough DV to do the job.

I concur with Harry Rhodan; that extra stage isn't doing you any favors. I estimate your LV-909 can handle a lot more of the workload. I design them to hit a minimum .7G and your design is getting about 2G.

Your lowest stage is also a little overworked. My math says to expect 1.2G out of the gate. I design mine to hit 1.4G.

2 stages can do this efficiently. The T45 in the middle is essentially a ton and a half of dead weight.

I also noticed that the fins may be a bit high on yours, which would cause it to be a little too unstable to track cleanly. Finally, your initial prograde kick looked like it was way too early and aggressive.

Best,

-Slashy

Edited September 30, 2015 by GoSlash27

[DancesWithSquirrels]

Your prograde kick is far too aggressive - I place fixed tailfins (not the tiny ones) just above the 1st stage engine, and I find that if I push over to somewhere between 5-10 degrees at 30-50 mps I can leave everything else alone for a gravity turn.

At that point I only have to start steering when I stage to 2nd, and 3 or 4 tiny fins on the second stage make that pretty worry free as well.

[Pawelk198604]

I want thanks to all of you for you help

It's true that we have here on of best gaming community and hobbyist on the internet

[Dafni]

Coyote27,

Just a matter of balance.

If the fins are too far back it's excessively- stable. Putting them there makes the rocket want to naturally follow a gravity turn.

That's important because the only source of guidance on these rockets is the reaction wheel in the command pod. If you design it to naturally tend to go where you want it to go, you need a lot less command authority. This aids stability when you don't have access to SAS.

Best,

-Slashy

Thank you so much for this advice! I never thought about it like that, but it makes perfect sense. Gotta go through my lifters now, I am sure I can improve their willingness to gravity-turn. I always put my fins all the way to the back and often have to fight them into the turn, thinking the rocket is almost too stable

Thanks again, great community, great game.

cheers to one and all