Do I have the technology for this ?

[Vindelle_Sunveam]

Hi, I want to send a ship to Minmus, with a lab, a Hitchicker Container (for RP purposes) and a little ship.

The problem is the lack of attitude control. this ship goes horizontal by itself (fine) at 4000m (not fine).

I know there are useless pieces such as nose cones, but those left are the ones I cannot commit to scratch from the blueprints without feeling silly. It has to look decent.

I realise I might want to cut some fuel on the lander, as well as scratch the RCS tank on it.

Here is my tech tree :

Full 45 points Tier, full 90 tier minus wings and 2.5m parts (skipper + poodle)

Docking and Lab techs are the only 160 unlocked.

Yes, control surfaces helped a lot !

Unfortunately, I just lack the oomph to get this in orbit while sticking to my design wills. when I unlock the Skipper, everything will be fine.

Thank you !

Edited July 29, 2014 by Vindelle_Sunveam
Answered

[UmbralRaptor]

Probably a critical shortage of control authority initially. Since you say you don't have any movable wings, I'd switch to all-liquid lower stages, and include some LV-T45s or Skippers. (The Skipper is actually quite capable now)

(Note that with stock aerodynamics, nosecones below the center of mass reduce craft stability)

[MarkyJ279]

It's a bit difficult to see but I think I can spot one problem.

About 1/3 of the way up just past the top of your liquid boosters the rocket thins to the point it looks like the entire orbital section is connected to your launch stage by one 1.25m fuel tank. This is almost certainly not strong enough for the load and your craft is probably bending over at that point. Once the top part starts sagging over it's going to drag the rest of your rocket over with it.

If you haven't already then you might try putting struts accross that gap to distribute the load a bit better. Maybe strut the liquid boosters to the small tanks or rockomax tank directly above?

If it's already strutted to hell and back then I don't know.

[Laie]

Lack of attitude control is solved by either reaction wheels or control surfaces. Both should be available at the 45-point tier. The tail-fin-...-rudder part is quite effective, as long as you still have some atmosphere.

[neamerjell]

In my experience, control surfaces are far more effective than reaction wheels while in the atmosphere. I usually attach them to the lower stages so I have at least four of them at 90 degree angles to each other. Another reason your ship is tipping over mid flight is that it is probably top heavy. Also, I second Markyj729's suggestion of adding struts between the boosters and the payload section.

[Sirrobert]

Something this heavy needs multiple reaction wheel parts to be able to control.

I'd put 1 on every main stage (doesn't need on the tiny ship, put the highest one next one to the lab)

Remember you need RCS on the little lander, if you want to be able to comfortably dock back to the lab

[MrXenox]

I'd agree with the people above, it definitely looks like you need more struts though. If your problem is at 4000 metres, then reaction wheels won't help too much, I think the answer definitely lies in moveable control surfaces.