Space Shuttle problem

[Pawelk198604]

Can someone tell what is wrong with my Space Shuttle, still falls into uncontrolled rotation that causes disintegration of the orbiter and the death of kerbonauts

i launching using mechjeb, setting parameters hdg to 90, starting gravity turn to 15 km finishing 70 km, final orbit to 100 km

i attached my project

[Whatshtisthis]

Some pictures would be useful, we might be able to tell you the problem just from the picture.

The change in centre of mass and thrust after staging is most probably the cause.

[Resender]

I see the same problem that's been plaguing my space shuttle

First your centre of mass and trust direction, you shuttle basically hangs on one side of the rocket unbalancing it.

This causing the tumbling as soon as the liquid fuel in the main stage weighs less then the shuttle.

Second I got a few questions about the orbiters design.

1)Where's the front wheel

2)Have you tested it's glider properties and capacity to get out of a tumble

Last I'll give you a compare between your current design and mine

My design can get out of a failed launch and land, yours can't cause it doesn't have a sufficient wing surface to make it in a glider, in attachment my design.

Note do that I haven't been able to get into orbit yet using this way

Edited October 17, 2012 by Resender

[Markus Reese]

I prefer to avoid dl any non .craft files, also takes time to dl, transfer to folder, etc. so pics are prefered. When it comes to "shuttle" launching, the usual cause is a thrust to cg imbalance. Essentially, if you get out of controlled x-axis spin, it is usually because you have more thrust on the "Bottom" or "Top" from the capsule's perspective. Z axis spin most of the time results from flex which can result in your engines pointing slightly off vertical. As spin increases, so does this flex until catastrophic failure.

[Pawelk198604]

I see the same problem that's been plaguing my space shuttle

First your centre of mass and trust direction, you shuttle basically hangs on one side of the rocket unbalancing it.

This causing the tumbling as soon as the liquid fuel in the main stage weighs less then the shuttle.

Second I got a few questions about the orbiters design.

1)Where's the front wheel

2)Have you tested it's glider properties and capacity to get out of a tumble

Last I'll give you a compare between your current design and mine

My design can get out of a failed launch and land, yours can't cause it doesn't have a sufficient wing surface to make it in a glider, in attachment my design.

Note do that I haven't been able to get into orbit yet using this way

Thanks, ill test you design but from what i see is definitely better than mine

Design space shuttles is not my specialty Definitely I'm better at designing traditional rockets, one even flew to MARS i mean DUNA ;-)

And this is my orginal Space Shuttle fajled launch

[Whatshtisthis]

Alternatively, you can launch the shuttle like a rocket.

[Pawelk198604]

Alternatively, you can launch the shuttle like a rocket.

Like rocket?

[Qumefox]

Stick your shuttle on the end of a normal rocket, instead of hanging it off the side.

'space shuttle emulation' builds are ridiculously hard to do in KSP for two reasons.. The real shuttle's main engines have gimbal ranges of almost 11 degrees, where as the largest gimbal range of a stock part in KSP is only 2.5 degrees I believe. Plus they're canted outwards. This high gimbal range lets the real shuttle, and droptank, tilt, and keep the center of thrust in line with the center of mass. The only way to accomplish this in KSP is to edit part cfg files, and fly manually. ASAS isn't capable of flying like this, and mechjeb isn't smart enough to either.

give me a min and i'll whip up a MS paint drawing of what i'm talking about.

Here we go.. (ignore the SRB's, they're gone by this stage of flight) As shown here, after the SRB's detach, the shuttle actually flies at an angle relative to it's direction of motion, which keeps the center of mass inline with the center of thrust, and by the time the SRB's are dumped, the shuttle is high enough that atmospheric drag isn't an extreme issue and the high engine gimbal range is able to adjust for it. Like I said, neither ASAS or mechjeb are capable of flying a craft in this kind of offset inclination currently. It can only be done manually at the moment.

[ATTACH=CONFIG]34911[/ATTACH]

Edited October 17, 2012 by Qumefox

[Resender]

Stick your shuttle on the end of a normal rocket, instead of hanging it off the side.

'space shuttle emulation' builds are ridiculously hard to do in KSP for two reasons.. The real shuttle's main engines have gimbal ranges of almost 11 degrees, where as the largest gimbal range of a stock part in KSP is only 2.5 degrees I believe. This high gimbal range lets the real shuttle, and droptank, tilt, and keep the center of thrust in line with the center of mass. The only way to accomplish this in KSP is to edit part cfg files, and fly manually. ASAS isn't capable of flying like this, and mechjeb isn't smart enough to either.

give me a min and i'll whip up a MS paint drawing of what i'm talking about.

Like this