SSTO flipping around after re-entry

[TarasK]

I made a cargo SSTO to let it send parts of my Mun space station. It flies well, re-entry from orbit isn't a problem for it, but after re-entry it flips over and fly backwards. I don't know how to fix that! Can you help me, please? I could leave link to craft, but i don't how.

[slayworldspite]

Uhh center of lift or mass i think i never make SSTO's so i don't understand much

[AoD_lexandro]

Your ship is tail heavy. This is normally caused by having an unbalanced fuel load, making the craft fly differently with low fuel or mass onboard.

If your not opposed to mods, I would suggest Correct CoL mod as this shows a nice graph of your full and empty states in flight.

[juanxlink]

Go on a diet, lighten that a$5.

As pointed, play with the empty vessel CoM on the SPA untill you get something stable in all situations.

[TarasK]

Originally posted by AoD_lexandro:

Your ship is tail heavy. This is normally caused by having an unbalanced fuel load, making the craft fly differently with low fuel or mass onboard.

If your not opposed to mods, I would suggest Correct CoL mod as this shows a nice graph of your full and empty states in flight.

I tried a lot of designs. I tried to put cargo bay on front and large fuel tank at back, tried to put cargo bay on back and large fuel tank at front, tried to put two small fuel tanks betwen cargo bay and that di not work. I'm just new in SSTOs and that is my second SSTO, and ill try that mod.

[TarasK]

Here is link for that big ass boi
https://steamcommunity.com/sharedfiles/filedetails/?id=1712454132

[alan85224]

Did you design the SSTO with full fuel tanks? Design it with empty fuel tanks and you will have more luck

[Chibbity]

Just looking at the pic, it's very tail heavy.

As it falls through the atmo it's going to want to fly like a dart. Heaviest part first, which is why it flips over.

You need to move some of that weight (specifically some engines) to the front, or seriously increase the drag at the rear for stabilization. (Deployable airbrakes on the tail for descent might help here.)

[TarasK]

Originally posted by Chibbity:

Just looking at the pic, it's very tail heavy.

As it falls through the atmo it's going to want to fly like a dart. Heaviest part first, which is why it flips over.

You need to move some of that weight (specifically some engines) to the front, or seriously increase the drag at the rear for stabilization. (Deployable airbrakes on the tail for descent might help here.)

Yeah, i will try that, thanks.

[TarasK]

Originally posted by alan85224:

Did you design the SSTO with full fuel tanks? Design it with empty fuel tanks and you will have more luck

I did not, but now i do, and ill try if its stable. Fill it up mod was very usefull for it

[Prophet_01]

There's also the debug menu to test things. Empty the fuel tanks and check the infinite fuel option to see how it does. Nice for a quick test flight.

Btw, it helps to angle the wings slightly upwards and put them as low as possible. It sdds a bit more stability. The elephant in the room is definitely mass destribution though. Airbrakes slow you down a lot. Good for reentry and landing, but tricky for flights and gliding. Better to fix this through wing positioning or maybe pumping fuel around.

[Chibbity]

As suggested above, CorrectCOL not only fixes problems with the stock COL indicator, but provides very nice readouts for dry vs. wet stability. So you don't have to bungle around draining tanks and refilling them.

Wind Tunnel mod is another one to check out if you like stats and charts about your plane.

[Prophet_01]

Originally posted by Chibbity:

Wind Tunnel mod is another one to check out if you like stats and charts about your plane.

Never heard of that one *--* Gotta install it right now! Thx!
Also, I miss FAR...

[Chibbity]

Originally posted by Prophet_01:

Originally posted by Chibbity:

Wind Tunnel mod is another one to check out if you like stats and charts about your plane.

Never heard of that one *--* Gotta install it right now! Thx!
Also, I miss FAR...

Not a problem!

FAR huh?

You're really gonna thank me after this then lol.

https://forum.kerbalspaceprogram.com/index.php?/topic/179445-14-17-ferram-aerospace-research-continued-v015100-lundgren-100419/&

[TarasK]

Originally posted by AoD_lexandro:

Your ship is tail heavy. This is normally caused by having an unbalanced fuel load, making the craft fly differently with low fuel or mass onboard.

If your not opposed to mods, I would suggest Correct CoL mod as this shows a nice graph of your full and empty states in flight.

Thanks man, Corect CoL helped a lot, as well as everyone who helped me! Now this thing can re-enter and land at KSC runway without problems.

Tomorow i gotta check if its able to get payload to orbit

[TarasK]

Originally posted by Chibbity:

Originally posted by Prophet_01:

Never heard of that one *--* Gotta install it right now! Thx!
Also, I miss FAR...

Not a problem!

FAR huh?

You're really gonna thank me after this then lol.

https://forum.kerbalspaceprogram.com/index.php?/topic/179445-14-17-ferram-aerospace-research-continued-v015100-lundgren-100419/&

This program allows you to download ANY mod even if dev didn't update to the latest version. https://www.youtube.com/watch?v=hEroWN_szeQ