what is wrong with this rocket?

[Lechu]

Can anyone please see why my rocket is tipping off the moment I take off?

I just cannot figure out what I am doing wrong.

Now, I do realise that payload area is kind of big, but I need it like that. How do I counteract?

Edited October 4, 2019 by Lechu

[Fierce Wolf]

Your payload is not specially big. Possible causes:

 

1) Your craft is not symetrical, download the KER mod, because otherwise you can't see your torque (tendency to fall to one size)

2) Control is given to a probe that is not pointing upwards.

3) Boosters are tilty in general, provide a lot of thrust but as weight is reduced it moves the center of gravity. Move (or remove) the boosters down.

4) I have clashing feelings about control surfaces in rockets Sometimes they are a must, others a nuisance. Careful using (so much) of those.

[Lechu]

22 minutes ago, Fierce Wolf said:

 

4) I have clashing feelings about control surfaces in rockets Sometimes they are a must, others a nuisance. Careful using (so much) of those.

These big control surfaces were an act of desperation. It did not work anyway. But....

 

22 minutes ago, Fierce Wolf said:

2) Control is given to a probe that is not pointing upwards.

 

Spot on. Thanks.  Cupola Module mounted upside down, in order to facilitate mounting it on the space station. When I reversed it's reaction wheel the rockets become stable. So, I did it to myself

Edited October 4, 2019 by Lechu

[bewing]

1 hour ago, Lechu said:

These big control surfaces were an act of desperation. It did not work anyway

Those are actually very small control surfaces. Only a very small portion of them actually adjusts. In your next design that needs control surfaces, use tailfins instead.

[Vanamonde]

Are you accelerating slowly off the pad? That gives you more time to "fall over," so to speak, and leaves you with less thrust to devote to steering. 

[Guest]

hmmm, do you have more than one control part? like multiple probe cores? i found a conflict sometimes with multiple control parts and a reset sometimes fixed it. with multiple cores in differnt orientations there is also a chance your craft might be starting with the wrong control point and think it's upsidedown maybe? just another guess, hope it helps

(wah i see you already fixed it?! i was close! :D)

Edited October 4, 2019 by Guest

[Pecan]

20 hours ago, Lechu said:

Cupola Module mounted upside down, in order to facilitate mounting it on the space station. When I reversed it's reaction wheel the rockets become stable. So, I did it to myself

Countdown checklist:
Before hitting space do the following if you want to get to space.

1. Engage SAS - rockets fall over sometimes.
2. Check your staging - we've all deployed parachutes on launch more times than we'll admit.
3. Check the navball - make sure it's all blue to show pointing up (in your case it would have been showing brown).
4. Check who's crew - a pillot in the science lab doesn't count.
5. Throttle to full - because 50% isn't love.

Ideally, you'll do ground tests before going for launch, so you know all the mechanics, action groups, etc. work.  Otherwise, prepare to test them as you fly.

[magnemoe]

You want an longer rocket, at least two orange tanks or one orange and one of the two engine boosters at bottom. Now add SRB for TWR. 
Control surfaces require airspead so if TWR is to low it will not get this. 

Has launched stupid stuff like this.

Yes the payload module is offset to adjust for center of mass the oversized control surfaces to compensate for the aerodynamic fails this will cause. 

[k00b]

On 10/4/2019 at 8:12 PM, Lechu said:

Spot on. Thanks.  Cupola Module mounted upside down, in order to facilitate mounting it on the space station. When I reversed it's reaction wheel the rockets become stable. So, I did it to myself

can someone explain this ?; if it is pointing straight down (instead of straight up) then what is the difference ? (on the basis reaction wheels don't supply thrust)

thanks

[AHHans]

7 hours ago, k00b said:

can someone explain this ?; if it is pointing straight down (instead of straight up) then what is the difference ?

If you don't use SAS, or only use the stability-assist SAS mode then it is still that the navball is the wrong side around and that the control is probably inverted to what most people expect. (The navball probably wasn't the OP's problem, because that should have been pretty obvious.)

I guess you can see the difference when using other SAS modes yourself. (If not, then please ask!)

I believe your confusion is the phrasing "reversed it's reaction wheel". You cannot change the reaction wheel orientation as such, they don't really have an orientation in-game. What you can do - and what I think @Lechu meant - is changing the orientation of the control point that the cupola module provides. That you can set to "reversed" so that a cupola that is mounted upside down will provide control in the direction that the rocket is actually pointed.

[Guest]

8 hours ago, k00b said:

can someone explain this ?; if it is pointing straight down (instead of straight up) then what is the difference ? (on the basis reaction wheels don't supply thrust)

If you use SAS in any other than base mode (prograde, surface radial out etc), it'll point the rocket in exactly the opposite way.

If you don't, your controls will still be reversed. You'll be pitching down when pulling up and so on.

Pilot skill/probe cores allowing, I usually launch by setting SAS radial out until the gravity turn, then starting the gravity turn manually, then setting SAS prograde. Which means that I have this particular oopsie, I do a somersault straight off the landing pad. Done it enough times by now that yeah I do check my navball as a matter of course.

[Geonovast]

A discussion of real life reaction wheels and relativity has been split off into its own thread here:

Please try to keep further discussion on the topic of this particular rocket.

Carry on.