Shuttle

[Billyk88]

Why when re entering the atmosphere does my shuttle flop around? I test flew it before launching it and it flew great. Please help.

 

Thank u

[Vaporo]

Pictures?

We can't be much help without pictures.

[The Optimist]

Some more information would be nice...

[Vanamonde]

Thread moved to the gameplay & help sub. 

[Speeding Mullet]

There's a few common reasons:

COM vs COL not correctly balanced

Incorrectly set up aerodynamics

Re-entry too steep, or AoA not ideal

Lack of control authority (SAS/RCS)

Pictures would help massively in diagnosing your specific issue.

SM

[Billyk88]

Ok ill get some pics up soon as i can.

[Billyk88]

here are some images of my shuttle there is nothing in cargo bay and at this time there are no rcs thrusters there is no fuel in it either. Thank you

, , ,

Edited December 12, 2015 by Billyk88

[Speeding Mullet]

Thanks for the pictures, couple of follow ups:

What altitude are you de-orbiting from, and what periapsis are you setting?  If you are de-orbiting from say 500km, then you don't really wan't your periapsis much under 47km or you will lose control.  If you're coming in from 1-200km you can go lower, but you want to try and bleed off as much speed as possible in the upper sections of the atmosphere.  Shuttle's slamming into thick atmosphere at speed have a tendency to lose control without amazing balance or lots of SAS/RCS.  With that in mind:

Definitely install RCS, only the most finely balanced shuttles can de-orbit without it, but you'll need it for orbital operations anyway so may as well put it in now and use the increased stability.

Install one large SAS ring at the front of the cargo bay if you haven't already (clip it into the cockpit using the offset tool if you want to hide it).

If you are still having issues then post your craft file and I can have a tinker and see if I can help out some more.

Thanks

SM

[GoSlash27]

Billyk88,

 FWIW, my shuttle has a body flap for additional pitch authority. My wings and strakes also have some incidence built in and I have 2 vertical tailfins merged so the rudder "splits" with braking, acting like an airbrake. That's all I can think of that I'm doing differently. I don't use RCS or reaction wheels on reentry and mine holds attitude nicely.

HTHs,

-Slashy

Edited December 13, 2015 by GoSlash27

[SlabGizor117]

The biggest problem is most likely the CoL.  Can you show some pics with fuel in it?  Even if the CoL is behind the CoM, those giant Elevons can really overcompensate.  I had a few problems with my shuttle too, so I'd like to know the answer also..

[Billyk88]

Yea sorry it took so long to reply been busy tryin different setups but still havent got it. Ill put pics of it with fuel in it soon. 

Thank u

Edited December 19, 2015 by Billyk88

[Vegetal]

Useful tip: Empty mk3 bays generate a lot of lift at high AoA. Lift that isn't accounted for in the editor, but it's there.