Why does my rocket flip in outer space?

[FilesUnknown]

https://kerbalx.com/FilesUnknown/boom-unmaned-wontwork-payload

I am in career mode and definitely made some research choice mistakes, please don't hold that against me. I am just trying to figure out if this is a glitch or a mechanic I haven't learned yet. 

I have my last stage here, manages to get this stage into orbit, but when I turn on the rocket the ship isn't stable. I tried googling flipping rocket but all they talk about is in atmosphere. The issue happens at 80,000+ km. Is this a bug?

The components are:

probodobodyne OKTO, two small inline reaction wheels, science jr, mobile processing lab with science stuff on it (with 4 solar panels) and rovemax model s2, adapter cone, fl-T200, fl-T400, Terrier.

Also I have batteries hidden under the adapter cone, and two communotron 16-s.

Everything is rotation symmetric.

 

For context this is the whole rocket below. It's goal is to get science lab to Mun.

https://kerbalx.com/FilesUnknown/boom-unmaned-wontwork-flipped

Edited May 28, 2019 by FilesUnknown
Spelling. craft files. fixed images? added solar panels. fixed the whole craft blueprint was incorrect, again.

[razark]

Dunno if it's just me, but I'm not seeing any screenshots.

If it's losing control outside of atmo, making sure your thrust vector is through your center of mass is what comes to my mind.

[Martian Emigrant]

@FilesUnknown Welcome to the forum.

 

Your pictures aren't showing up.

[James Kerman]

6 hours ago, FilesUnknown said:

Also I have batteries hidden under the adapter cone

Welcome to the forum!

I don't see any power generation components in your list. Do you have solar panels or a fuel cell replenishing the batteries? If not the mobile processing lab will quickly use up the power stored in your batteries.

Also the reason why your pictures are not visible is that the forum itself does not host images. You will need to upload your pictures to a hosting service like imgur (it's free and easy to use but any image hosting service should work) and then link to them in the forum.

[Guest]

Yeah no pictures.

It's almost certainly not a bug, or else you've discovered something really cool and really exotic in which case you need to (1) congratulate yourself and (2) turn it into a K-drive.

Vacuum instability is almost always due to asymmetrical thrust, although that shouldn't happen with radially symmetric designs. If you can upload your craft to KerbalX or somewhere I can take a look to attempt to diagnose.

[Richy teh space man]

You can also post your craft blueprints, that way we can have a look

[FilesUnknown]

Thank you everyone for the quick replies! I am sorry the images aren't working. I'll lurk for a post on how to post images, that work.

I added the craft files for the payload (rotated to make sense) and the whole craft.

[FilesUnknown]

2 hours ago, James Kerman said:

Welcome to the forum!

I don't see any power generation components in your list. Do you have solar panels or a fuel cell replenishing the batteries? If not the mobile processing lab will quickly use up the power stored in your batteries.

Also the reason why your pictures are not visible is that the forum itself does not host images. You will need to upload your pictures to a hosting service like imgur (it's free and easy to use but any image hosting service should work) and then link to them in the forum.

I tried using google images but that didn't work. I am trying imgur now hopefully it works. I don't know because I can't seem to see my post when I am not logged in.

Also I forgot to mention I have 4 solar panels.

Edited May 28, 2019 by FilesUnknown
solar panels

[FilesUnknown]

Yay screenshots now work! Thanks James Kerman about the Imgur advice.

[Ratwerke_Actual]

Have you checked your Navball

In flight, does the control point change?

[MechBFP]

Do you have any mods installed?

What you have should work just fine, especially with reaction wheels and an engine with gimbal. 

The only other thing I can ask is, do you have SAS enabled while in orbit? If not, then your vessel will generally go all over the place because it isn’t stabilized by the reaction wheels. 

[Xavven]

Does your rocket bend at all when under acceleration? That could cause the CoM to veer off the thrust line.

[Nich]

Also simitry does not always work especially if you are putting symmetric parts on symmetric parts.  you could try taking off and putting back on.  Also make sure something was not put on with mirror simitry by accident.

[FilesUnknown]

 

53 minutes ago, MechBFP said:

Do you have any mods installed?

What you have should work just fine, especially with reaction wheels and an engine with gimbal. 

The only other thing I can ask is, do you have SAS enabled while in orbit? If not, then your vessel will generally go all over the place because it isn’t stabilized by the reaction wheels. 

 

No mods installed only vanilla.

50 minutes ago, Xavven said:

Does your rocket bend at all when under acceleration? That could cause the CoM to veer off the thrust line.

.Doesn't bend in space but used to bend at takeoff until I flipped it around.

 

53 minutes ago, MechBFP said:

Do you have any mods installed?

What you have should work just fine, especially with reaction wheels and an engine with gimbal. 

The only other thing I can ask is, do you have SAS enabled while in orbit? If not, then your vessel will generally go all over the place because it isn’t stabilized by the reaction wheels. 

Sas is enabled when it flips. I don't even though the controls and it flips.

1 hour ago, Ratwerke_Actual said:

Have you checked your Navball

In flight, does the control point change?

Control point doesn't change, but I wish the control point would flip.

53 minutes ago, MechBFP said:

Do you have any mods installed?

What you have should work just fine, especially with reaction wheels and an engine with gimbal. 

The only other thing I can ask is, do you have SAS enabled while in orbit? If not, then your vessel will generally go all over the place because it isn’t stabilized by the reaction wheels. 

Edited May 28, 2019 by FilesUnknown

[MechBFP]

Press alt+x. Maybe you accidentally have trim set?

[Jimmidii]

SAS has some autopilot functions, all of them except Stability Assist are there to keep a craft oriented in a particular direction relative to the craft's orbit, and they fight against anything that changes that orientation, including the player's input.

Check the little icons next to the Navball when SAS is enabled to check that it's 'Stability Assist' that's selected.

[Kerbart]

The first image shows your craft upside down compared to when it’s joined with the launch vehicle in the second image. There also appears to be a control unit on top of the launcher, just underneath the nose cone.

Could it be that, when you’re reaching space and staging, the second control unit (the one on your ship) takes over but that one is now mounted upside down compared to what you think is “up” for the vessel? Since it’s traveling backwards, telling SAS to aim it prograde will result in pointing it in the wrong direction. Because the control unit will orient itself prograde but as it’s upside down mounted, the rest of the ship will turn retrograde, resulting in the problem that you are describing.

[Flavio hc16]

so, i downloaded your craft  ( the 2nd one)and started doing some trials....

is somewhat a mess.

-this is what KER read:  

so i can already tell you that the craft is:

overengineered ( you need 3.4k+0.9k.0.4km/s of deltaV, you have them in the first 2 stages, not counting the 3rd), you could probably reach duna's orbit in stock

-also, as other have pointed out: 

so your lab has no mean to communicate ( so you will lose control at some very early point) and can't generate power, so your lab can't run for more than probably an our before running out of electricity and can't even transmit back the data it developed.

-too much TWR ( thrust-to-weight ratio) at the launchpad, you are wasting a crapton of you power and are making your rocket very hard to fly.

-adding insult to injury to the last point ( hard to fly in the atmosphere) 

1) you COM (center of mass, the yellow ball) is below the COL (center of lift, the blue ball) so your rocket will want to flip in the atmosphere ( you are trying to make an arrow fly backward)

2) aerodynamically speaking is a mess: you are not using adapter below your lab, so you have a crapton of drag , you don't have ( probably even researched yet) controllable flap/wings so flying it at high speed is very hard, and you don't have any probecore with at least SAS. ( in the 1st craft, the 2nd has it but is still underpowered compared to you aero's problems)

 

and those are the problem of the whole craft. talking about your payload ( your 2nd craft)

in vacuum, I started doing a burn without SAS engaged, and everything  went normal ( you can see from the "thrust torque readout that it says "0")

 

.....then I engaged SAS....and this happened

as you can see the thrust torque readout from KER says 60kn-m, and the rocket started flipping like crazy

 

then i saw a little detail: THE PROBE CORE IS INVERTED!!!!!!!  this is why your rocket starts flipping, when you give it a nudge the SAS will try to compensate, but as it is mounted upsidedown it will actually make things worse instead of correct it.

rotating the probe core resolved the issue

 

p.s. don't worry iwth your first carrees and rockets being a mess, that's normal and part of the (steep) learning curve of ksp, we all improve

 

 

 

 

 

 

 

[Ratwerke_Actual]

4 minutes ago, Flavio hc16 said:

 

 

 

 

 

 

 

Notice the color on the Navball.....

That's the reason I said check it.

It's telling you its reversed control.

[Nich]

I thought this used to work with rockets.  Pretty sure I have had to thrust prograde to slowdown on multiple AERO entry vehicles.  Flight control surfaces have never been able to handle flying backwards as they would constantly correct in the wrong direction.

[FilesUnknown]

1 hour ago, Jimmidii said:

SAS has some autopilot functions, all of them except Stability Assist are there to keep a craft oriented in a particular direction relative to the craft's orbit, and they fight against anything that changes that orientation, including the player's input.

Check the little icons next to the Navball when SAS is enabled to check that it's 'Stability Assist' that's selected.

I have no options except stability assist this early on in my career, but I see how that would cause a problem.

 

1 hour ago, Ratwerke_Actual said:

Notice the color on the Navball.....

That's the reason I said check it.

It's telling you its reversed control.

I know the direction changed but I didn't think that ment the orientation of control changed.

1 hour ago, Kerbart said:

The first image shows your craft upside down compared to when it’s joined with the launch vehicle in the second image. There also appears to be a control unit on top of the launcher, just underneath the nose cone.

Could it be that, when you’re reaching space and staging, the second control unit (the one on your ship) takes over but that one is now mounted upside down compared to what you think is “up” for the vessel? Since it’s traveling backwards, telling SAS to aim it prograde will result in pointing it in the wrong direction. Because the control unit will orient itself prograde but as it’s upside down mounted, the rest of the ship will turn retrograde, resulting in the problem that you are describing.

I don't have any prograde controls sadly I only have stability assist.

 

@Ratwerke_Actual

I will correct the inverted remote control! Thank you for letting me know that would cause the issue!

[FilesUnknown]

1 hour ago, Flavio hc16 said:

so, i downloaded your craft  ( the 2nd one)and started doing some trials....

is somewhat a mess.

-this is what KER read:  

so i can already tell you that the craft is:

overengineered ( you need 3.4k+0.9k.0.4km/s of deltaV, you have them in the first 2 stages, not counting the 3rd), you could probably reach duna's orbit in stock

-also, as other have pointed out: 

so your lab has no mean to communicate ( so you will lose control at some very early point) and can't generate power, so your lab can't run for more than probably an our before running out of electricity and can't even transmit back the data it developed.

-too much TWR ( thrust-to-weight ratio) at the launchpad, you are wasting a crapton of you power and are making your rocket very hard to fly.

-adding insult to injury to the last point ( hard to fly in the atmosphere) 

1) you COM (center of mass, the yellow ball) is below the COL (center of lift, the blue ball) so your rocket will want to flip in the atmosphere ( you are trying to make an arrow fly backward)

2) aerodynamically speaking is a mess: you are not using adapter below your lab, so you have a crapton of drag , you don't have ( probably even researched yet) controllable flap/wings so flying it at high speed is very hard, and you don't have any probecore with at least SAS. ( in the 1st craft, the 2nd has it but is still underpowered compared to you aero's problems)

 

and those are the problem of the whole craft. talking about your payload ( your 2nd craft)

in vacuum, I started doing a burn without SAS engaged, and everything  went normal ( you can see from the "thrust torque readout that it says "0")

Sorry you had to make your own launch craft. I uploaded the previous version that wouldn't fly instead of the current version that freeks out in atmosphere. But my design didn't change a bit other than flipping it around, so all your points are valid.

[FilesUnknown]

One thing I don't get is why should it matter the orientation as to whether it flips without SAS?

I mean it should be blasting the same way when uncontrolled and SAS off regardless of orientation.

Also thank you everyone for being patent with my issues of posting images and blueprints!

Edited May 28, 2019 by FilesUnknown
clarity.

[Flavio hc16]

22 minutes ago, FilesUnknown said:

One thing I don't get is why should it matter the orientation as to whether it flips without SAS?

I mean it should be blasting the same way when uncontrolled and SAS off regardless of orientation.

Also thank you everyone for being patent with my issues of posting images and blueprints!

without SAS engaged your craft is stable in fact

[FilesUnknown]

17 minutes ago, Flavio hc16 said:

without SAS engaged your craft is stable in fact

It is now after flipping the remote control module, but before flipping the remote control module the thing wouldn't be stable with or without SAS engaged.

Actually you are right it was the SAS engaged. Now it makes sense.

Edited May 28, 2019 by FilesUnknown
mistaken