Soyuz Q

[Lohan2008]

I tried building a Soyuz (soviet) style rocket BUTT it went sideways >>> My design needs fixing, Da ?

Edited September 13, 2013 by Lohan2008

[Specialist290]

The main thing seems to be that you don't have anything on there to keep it stable. I'd suggest putting fins on the outside orange tanks, plus maybe a reaction wheel or two in the main stack.

[capi3101]

Yeah...those look like LV-T30s solely on the booster (and SRBs of course). Good engine, but they don't offer any steering authority. Reaction wheels, fins, and consider trading out the engines you've got in the center with some LV-T45s (those vector and therefore give you some good steering authority).

[Lohan2008]

Thanks for suggestions > LV-T45s

Edited September 13, 2013 by Lohan2008

[Lohan2008]

NOW I understand why the Russians (sic) used that design !

It may be slower but it is steady and stronger.

[capi3101]

30s and 45s in concert usually work very well with one another - 30s provide power, 45s provide steering. In any design, the 45s work best centerline with the 30s outboard, particularly if you're using any kind of radial staging - the place you need the most thrust is at launch. By using both, you get the benefits of both. Even with larger rockets, those engines are good choices (best launch Isp of any of the smaller engine types except for Aerospikes, and the 'spikes have their own issues).

Glad I could be of help.

[SRV Ron]

More bracing is needed on the SRB and or the outboard orange tanks. They are twisting which is causing the tilt. I cannot tell what type of staging you are using which can also affect how this design should be braced. The SRB you are using can be steered.

capi3101 is correct about the use of the LV-T30s and LV-T45s.

Control of twisting under power is key to stability on such large designs. A large SAS on the boost stage may be needed for additional stability while the built in one on the upper stage command capsule should handle its needs.

Also, I notice that the SAS is off.

RCS is generally ineffective in the atmosphere.

[SRV Ron]

It gives their rocket a lot of power for launch, then later drops all of that weight when the outboard rockets are no longer needed for flight. The US ICBM Atlas does something similar by dropping its two outboard rockets when their power is no longer needed.