Can't get MechJeb Ascent Guidance to work

[CosmicCharlie]

Been trying a couple hours and haven't gotten a ship into a stable orbit. Sometimes it turns circles on ascent (note the navball in the pic), sometimes drops back into the atmosphere when circularizing. Never achieves stable orbit.

Any ideas?

[Harry Rhodan]

That rocket in the background looks extremely overpowered and unaerodynamic.

[EliasDanger]

Limiting the AoA to 2.5 instead of 5.0 helps my ascents stay stabe. And you probably want corrective steering

[Tex_NL]

Try to design more aerodynamicly

Do use 'Prevent overheats' This will stop you from blowing up your engines. It's rare but it sucks when it happens.

Do not use 'Limit to terminal velocity' It's bugged, inaccurate and therefore doesn't help.

Do use 'Corrective steering' This will keep you on track better.

AoA at 5.0 is just fine. I've got mine on 10 and never run into problems.

Your ascent path is WAY to steep. Start your turn as early as possible with a turn shape of 40%.

[maltesh]

Indeed, your rocket is not aerodynamic, and that causes a host of issues in 1.0+

The lift profile I usually use is this one (assuming aerodynamic issues have been dealt with)

About 45% turn shape.

Limit Acceleration to 18 m/s ^2.

Begin Gravity Turn Immediately.

I usually, but not always, use corrective steering, and limit AOA to 5°

[Red Shirt]

I've never used the editor. Setting limit acceleration to 20 m/s and using corrective steering are the only settings I use differently. If that doesn't help try adding fins.

[rudi1291]

Make sure your TWR is basically >1.3 for the whole launch. MJ can´t handle craft with less. Also, keep in mind that MJ is nothing magical. If you can´t get your rocket to orbit, MJ won´t do either

[CosmicCharlie]

Yeah, the rocket sucks. But I've tried it on plenty of rockets I've gotten into orbit. No luck.

OK, I'll try some of these suggestions. Thanks all.

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But why wouldn't you want to go straight up until you get out of most of the atmosphere? I picked 18km because it's out of 2/3 of the atmosphere. But you folks are saying 5km? Or less?

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Got to the edge of the atmosphere. See how it's circularizing at 46km. And dropping.

Edited October 11, 2015 by CosmicCharlie
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