Can someone help me with this lifter? (RSS/RO)

[Kerbal01]

I am attempting to build an all hydrolox version of Titan Centaur. Built the thing sans Centaur, it flew fine once. added a Centaur, it flips at MaxQ. I suspect it is because of the giant long fairing, like on the real titan. Can anyone help. Link to suspect craft: https://www.dropbox.com/s/hcz9jy725mxs3qm/Hydrolox titan.craft?dl=0 Requires RSS/RO and dependencies. Album: http://imgur.com/a/679cH

Edited July 21, 2016 by DarthVader

[Snark]

1 hour ago, DarthVader said:

I am attempting to build an all hydrolox version of Titan Centaur. Built the thing sans Centaur, it flew fine once. added a Centaur, it flips at MaxQ. I suspect it is because of the giant long fairing, like on the real titan. Can anyone help. Link to suspect craft: https://www.dropbox.com/s/hcz9jy725mxs3qm/Hydrolox titan.craft?dl=0 Requires RSS/RO and dependencies.

Screenshot?

(A screenshot can actually be more helpful than a craft file, in many cases-- it allows lots of problems to be diagnosed at a glance, rather than requiring someone to manually download a file, install it, spin up the game, go through a launch sequence, etc.)

[dafidge9898]

The problem is the center of lift is way, way to high above the center of mass. Also because you have such a heavy payload so high up on the rocket. For the rocket to be stable during launch you have it perfectly heading down surface prograde. It seems fine if you keep it like that. The rocket is also very wobbly. Try securing the payload more. The wobble most definitely contributes to sending the rocket into a rapid unplanned disassembly (by wobbling it slightly out of flow of oncoming air). 

And I can't help myself, but your rocket design needs improvement. Vacuum engines on the first stage are not the smartest choice, and ballon and cryogenic balloon tanks are really helpful if you want that extra 500 dv. since you're going for a hydrolox core stage, I would choose something like an RS-25 or an RD-0120 from the Soviet Engines Pack.

Also: The rocket is just straight up not going to make it to orbit with its current payload.

Edited July 20, 2016 by dafidge9898
Addition

[Kerbal01]

On ‎7‎/‎19‎/‎2016 at 8:51 PM, dafidge9898 said:

The problem is the center of lift is way, way to high above the center of mass. Also because you have such a heavy payload so high up on the rocket. For the rocket to be stable during launch you have it perfectly heading down surface prograde. It seems fine if you keep it like that. The rocket is also very wobbly. Try securing the payload more. The wobble most definitely contributes to sending the rocket into a rapid unplanned disassembly (by wobbling it slightly out of flow of oncoming air). 

And I can't help myself, but your rocket design needs improvement. Vacuum engines on the first stage are not the smartest choice, and ballon and cryogenic balloon tanks are really helpful if you want that extra 500 dv. since you're going for a hydrolox core stage, I would choose something like an RS-25 or an RD-0120 from the Soviet Engines Pack.

Also: The rocket is just straight up not going to make it to orbit with its current payload.

The boosters do all the flight through atmosphere, the vacuum engines are started above the karman line.

[dafidge9898]

11 minutes ago, DarthVader said:

The boosters do all the flight through atmosphere, the vacuum engines are started above the karman line.

Oh oh oh ok my mistake. 

[Kerbal01]

22 minutes ago, dafidge9898 said:

Oh oh oh ok my mistake. 

though I do agree that the too heavy payload is centered too high, but this is how the real thing worked, I guess ill have to fake it to get it to work proper.

[Kerbal01]

Added Imgur album of craft In VAB, on pad and in flight with FAR data.

[Gaarst]

12 minutes ago, DarthVader said:

Added Imgur album of craft In VAB, on pad and in flight with FAR data.

Imgur album isn't displayed and the ID doesn't seem to work anyway.

To insert an Imgur album, click on the "i" button at the very right of the editor bar and paste the album ID there.

Above is the result with the ID you've given, I suggest double-checking it

Edited July 21, 2016 by Gaarst

[Kerbal01]

20 minutes ago, Gaarst said:

Imgur album isn't displayed and the ID doesn't seem to work anyway.

To insert an Imgur album, click on the "i" button at the very right of the editor bar and paste the album ID there.

Above is the result with the ID you've given, I suggest double-checking it

try it again, I fixed the link.

[Gaarst]

Just now, DarthVader said:

try it again, I fixed the link.

Nope still can't see the link. I think your album is set as private so that only you can see it.

[Kerbal01]

fixed album again, set to public.

[Palaceviking]

Have you got fins/control surfaces near the bottom/back of your main rocket? 

If you don't want too much drag I sometimes stagger my fins across earlier stages so I lose drag as I ascend.

[Kerbal01]

4 hours ago, Palaceviking said:

Have you got fins/control surfaces near the bottom/back of your main rocket? 

If you don't want too much drag I sometimes stagger my fins across earlier stages so I lose drag as I ascend.

The real vehicle does not have find, so I can't put find on