@HeartFoam
No need for mods.
Set to 10km in the game and then do as the turorial:
https://www.bilibili.com/video/BV1GB4y1C7C6/?sharesource=copyweb&vd_source=b5ce023e28fdf791f89cad36d1b48479

@HeartFoam
You're welcome. I'm glad to hear any problems encountered during use.

@centurion88 Thank you. You're the best. I'll try it soon. 👍

Edit. No. That fixes nothing. Firstly, max physics distance without any mods is 10km, and secondly this doesn't explain why the craft can't fly itself to orbit when its the active craft.

@HeartFoam
I got it. The upper stage is controlled by a command chip on it, but the game will not run any Vizzy programs on the craft beyond the physics distance. Therefore, when distsnce between upper stage and the booster under your control is further than 5km, the upper stage lost control, and you can also see the booster losing control if you switch to the upper stage manually after seperation. And this is why you're suggested to set the physics distance as more as possible, a feasible value is 500km.

@centurion88 I've tried 200km, 250km, 400km, 500km, I've tried using a lighter payload. It consistently falls back and burns up. Physics distance 5km, I've never changed it. The upper stage has more than enough DeltaV, but never uses it to circularize.

I'm doing a flight now. Switched back to upper stage at ASL 170km. But it's burning straight down to Droo. Past 100km. At 80km ASL. So far, no attempt to pitch at any point. We're burning up. We're dead.

@HeartFoam
How far is your physixs distance? What orbit parameters did you input?

There's a problem with the upper stage not trying to raise periapsis. After landing the booster, and switching to the uppper stage, it just falls to earth. It makes no attempt to orbit.

epic

good