Rocket Turns Around and Crashes When Re-Entering from a Sub-orbit

[EnderPig]

Hello. I've just come back to Kerbal Space Program after not playing it for about half a year and I'm doing career mode. The only mod I have on is MechJeb.

I'm trying to complete a contract where I have to fly two tourists to a sub-orbit and back. The problem is that, whenever I come back from the sub-orbit, the command pod and the crew cabin start going crazy at re-entry and it starts facing straight towards Kerbin, even if I try holding it at the retrograde vector, and eventually it crashes down on the ground. I've tried doing this with a few different rockets and every time it has done the same thing. The picture shows the latest rocket, which I tried too, hoping that the two extra engines would help it stay steady and not turn, but they ended up exploding and the same thing happened again. I've been stuck here for many hours trying to figure it out but I just can't do it. Does anyone here have any advice how to survive the re-entry and get both the command pod and the crew cabin safely down from a sub-orbit? I've done this before, but only with a command pod. Thanks.

[Superfluous J]

That passenger cabin is very light, so your ship is front-heavy and flips around. Also, that mystery goo is adding drag at the front on descent. You basically have 2 options:

1. Add lots of reaction wheels (1 or 2 would probably do it) and tell your pilot to hold retrograde on the way down.
2. Redesign it so the passenger cabin is on top of the pod and the pod has the heat shield, so it's really ugly bottom-heavy, and stays facing the correct way naturally.

And in either case, put that mystery goo up near the top of the descending rocket so it helps your drag instead of hurting it. Also, I'd add a drogue chute. Those can open at much higher speeds. You open it first, let it slow you down, and then open the main chute.

You *may* be able to save the current ship on re-entry, by aiming upward on descent. This will actually cause you to glide a bit (Not much, but a bit) and slow down a little more. and slow down enough to hit the chute. Probably not, though it's worth a shot.

Edited September 17, 2017 by 5thHorseman
I misspoke about the placement of the mystery goo.

[Geonovast]

Just ran a quick test.  Obviously not the same conditions you have, but;  I added some cat ears to the top of the command pod.  Might throw off your launch (I just debugged my way to orbit), but you could make changes to the rocket to adjust for that.  The fins did explode on re-entry, but the craft stayed stable the whole way down.  I came in fairly shallow, my periapsis was about 40k.

Also note you might want to raise the slider for when your chute opens.  On mine, it opened at 1000, but the pod didn't slow down to a safe speed until ~20 meters above the water.  A split second longer and it would have at least exploded the cabin.

(Yes I have the goo canister on that.)

[EnderPig]

3 hours ago, 5thHorseman said:

That passenger cabin is very light, so your ship is front-heavy and flips around. Also, that mystery goo is adding drag at the front on descent. You basically have 2 options:

1. Add lots of reaction wheels (1 or 2 would probably do it) and tell your pilot to hold retrograde on the way down.
2. Redesign it so the passenger cabin is on top of the pod and the pod has the heat shield, so it's really ugly bottom-heavy, and stays facing the correct way naturally.

And in either case, put that mystery goo up near the top of the descending rocket so it helps your drag instead of hurting it. Also, I'd add a drogue chute. Those can open at much higher speeds. You open it first, let it slow you down, and then open the main chute.

You *may* be able to save the current ship on re-entry, by aiming upward on descent. This will actually cause you to glide a bit (Not much, but a bit) and slow down a little more. and slow down enough to hit the chute. Probably not, though it's worth a shot.

Thank you! Adding two reactor wheels seemed to work. I landed safely without any damage.

[Dnarbnellih2]

Another way to go about it is to add 4-6 A.I.R.B.R.A.K.E.S. if you have them yet, you can put them on the passenger cabin, and on reentry, open them, they do miracles on slowing you down and it will cause your front half to naturally want to point retrograde, but its tricky if you go in prograde because then your aerodynamics may keep you from turning around, so as long as you point retrograde upon reentry, you should be fine, but the airbrakes can get quite hot if you're going much over 2000 m/s, so be careful.

Edited September 17, 2017 by Dnarbnellih2