How to stop larger rockets from flipping

[Drewskii]

Right now, my only solution is to go straight up on the 3rd and 2nd stages until I reach 70000 M and then attempt to raise my periapsis above 70000 M. I believe this problem revolves around going straight up on launch to stop flipping. In other words, how do you stop flipping?

[Chibbity]

A proper rocket is like an arrow.

Mass at the tip, long sturdy shaft, fins at the back.

A good gravity turn is done very slowly, started right off the pad, and completed before 10kish.

Also, autostrut to get rid of any wobbling.

[Drewskii]

Ah. The mass on my rocket is lower. Weird question: what is the best way to raise it?

[Chibbity]

Originally posted by Weeaboo:

Ah. The mass on my rocket is lower. Weird question: what is the best way to raise it?

Well...literally raising it.

If your rocket is short and squat and wide you may want to consider redesigning it somewhat.

However, you might get away with just adding lot's of drag at the rear. Slap some tail fins/wings to the bottom. Reaction wheels never hurt either if a rocket is a pain in the butt to keep from flipping.

[Drewskii]

Originally posted by Chibbity:

Originally posted by Weeaboo:

Ah. The mass on my rocket is lower. Weird question: what is the best way to raise it?

Well...literally raising it.

If your rocket is short and squat and wide you may want to consider redesigning it somewhat.

However, you might get away with just adding lot's of drag at the rear. Slap some tail fins/wings to the bottom. Reaction wheels never hurt either if a rocket is a pain in the butt to keep from flipping.

I currently have a probe in a low Mun orbit. I can try grinding some science out of it to buy some new parts.

[Chibbity]

Originally posted by Weeaboo:

Originally posted by Chibbity:

Well...literally raising it.

If your rocket is short and squat and wide you may want to consider redesigning it somewhat.

However, you might get away with just adding lot's of drag at the rear. Slap some tail fins/wings to the bottom. Reaction wheels never hurt either if a rocket is a pain in the butt to keep from flipping.

I currently have a probe in a low Mun orbit. I can try grinding some science out of it to buy some new parts.

Is this an early game Career save?

Even the most basic of wings/control surfaces will work; just add more of them.

Really, anything draggy at the base of the rocket will help, even non aero surfaces. Also, command pods and some probe cores come with built in reaction wheels, adding an empty command pod to your ship for better SAS is a viable solution in the early game.

[Drewskii]

Originally posted by Chibbity:

Originally posted by Weeaboo:

I currently have a probe in a low Mun orbit. I can try grinding some science out of it to buy some new parts.

Is this an early game Career save?

Even the most basic of wings/control surfaces will work; just add more of them.

Really, anything draggy at the base of the rocket will help, even non aero surfaces. Also, command pods and some probe cores come with built in reaction wheels, adding an empty command pod to your ship for better SAS is a viable solution in the early game.

I'm more in the early middle game, starting to get into the 160 science parts.


Also it's science mode.

[Chibbity]

Originally posted by Weeaboo:

Originally posted by Chibbity:

Is this an early game Career save?

Even the most basic of wings/control surfaces will work; just add more of them.

Really, anything draggy at the base of the rocket will help, even non aero surfaces. Also, command pods and some probe cores come with built in reaction wheels, adding an empty command pod to your ship for better SAS is a viable solution in the early game.

I'm more in the early middle game, starting to get into the 160 science parts.


Also it's science mode.

Ahh, I see. (A screenie of the rocket would certainly help if you had one.)

The gravity turn doesn't have to be perfect either, for a large or cumbersome rocket; you can spend more time going vertical but the important thing is to turn slowly and gradually, trying to crank it over suddenly is bound to end badly.

If you have insane TWR off the pad that can be an issue too, and cause flipping; you want to go fast, but not too fast.

[whatdoesthisbuttondo?]

A common problem people tend to overlook with multiple fuel tank stages (you tend to have those early- and mid-game a lot) is your center of mass moving downward when draining fuel tanks, as it will drain the tanks in the stage from the top down.

This can be solved with fuel lines from the bottom tanks to the upper tanks, disabling fuel feed from upper tanks until lower tanks are empty (requires fast clicking), or a simple redesign of the rocket.

Decoupling can be another source of flipping, with tall stages that are fully drained, the engines will drag the center of mass down, and decoupling will then jerk the center of mass suddenly upwards, which can cause a flip.

[Astronaut]

try to hit 10 degrees every 8000m, gradually. For example, don't wait until 8000m to turn. Gradulally apply this so that every 800m you have 10 degrees more. Also add fins. Make sure center of lift is under center of mass.
The math:
Navball can only display 180 degrees at once. Half the navball, which is 90 degrees in diameter, has the launch trajectory your craft will follow. 90 divided by 10 is 9. 10 is ten degrees. 9 is 9x10. That is 90. Which means that you should split the path into 9 parts. Pitch ten degrees on each part. 70000m, the atmosphere height, divided by 9 (the upper atmosphere doesn't really have aerodynamic effects.), gives you about 8000m. A more accurate estimate is 7500 to 8000, but stick with 8000m. Don't forget start pitch over when you have reached at least 100 meters per second

[RoofCat]

Originally posted by Astronaut:

try to hit 10 degrees every 8000m, gradually. For example, don't wait until 8000m to turn. Gradulally apply this so that every 800m you have 10 degrees more. Also add fins. Make sure center of lift is under center of mass.
The math:
Navball can only display 180 degrees at once. Half the navball, which is 90 degrees in diameter, has the launch trajectory your craft will follow. 90 divided by 10 is 9. 10 is ten degrees. 9 is 9x10. That is 90. Which means that you should split the path into 9 parts. Pitch ten degrees on each part. 70000m, the atmosphere height, divided by 9 (the upper atmosphere doesn't really have aerodynamic effects.), gives you about 8000m. A more accurate estimate is 7500 to 8000, but stick with 8000m. Don't forget start pitch over when you have reached at least 100 meters per second

are you trying to teach him circle or parabola?

At ~30km you should be at ~30°.

Now explain me, how to divide the first 30km by 6 (90°-30°) and then remaining 40km by 3 (30° left) to get the same number, genius :)


Actually, during gravity turn you just initiate and then let that gravity do the rest. There is no need to push anything. Still haven't done TRAINING mission, I see.

[Ogre420]

Hope this helps...

In the newest versions of the game high speeds and hard turns in atmo equals crashes.
NOTE: This applies to re-entry also.

For improved stability from launches in Ver. 1.0.+....

Add fins to BOTTOM centerline of EACH stage of your rocket that you expect to be firing below 45k.
(Make sure that they are NOT AIR BLOCKED by fairings or other stuff above.)
Fins on booster stages or fins that are NOT centerline are OK also, but remember that the fins drop off with the boosters.

Turn OFF all thrust vectoring from any firing engine in each stage that is NOT dead center (can be done in VAB)

If you are seeing MACH EFFECTS (The white speed lines around the rocket) throttle back if you can until they disappear.

The nav ball has a flying "V" with a DOT dead center that shows where the rocket is POINTED.
The PROgrade marker (Circle with 3 lines around the outside in a cross pattern) shows where the craft is GOING.
To be safe make sure that the DOT in the flying "V" does NOT go past the ends of those lines on the outside of the PROgrade marker during your grav turn.

SAS and RCS can help keep the craft stable durring the grav turn, extra SAS units can be added (and dropped) with booster stages. If you add RCS JUST for the stability assist during launch, place the monoprop tanks/RCS thrusters where they can be ditched as you reach orbit.

If you are launching with solid rockets as your main boosters around a liquid engine, add a bit more fuel and have the liquid engine firing at low throttle for the thrust vectoring during the SRB's burn.

All rockets and launches are different but as a rule of thumb...
Get to 150 m/s as fast as possible then a slow throttle up to 200 m/s at 10k.
From 10k to 20k a slow throttle up to 350 m/s.
From 20k to 30k a slow throttle up to 500 m/s.
After 30k it's usually safe to floor it and go max throttle.

As you leave the launch pad you will want to start your gravity turn.
If you DIDN'T rotate your control part in the VAB, then that means pressing the "D" key for a zero degree (Equatorial) orbit.

For beginers I suggest a 5 degree turn per 1k meters of altitude until you get to 45 deg. angle.

0k-1k 90 deg. (Straight up . Get to 150 m/s as fast as possible)
1k-2k 85 deg.
2k-3k 80 deg.
3k-4k 75 deg.
4k-5k 70 deg.
5k-6k 65 deg.
6k-7k 60 deg.
7k-8k 55 deg.
8k-9k 50 deg.
9k-10k 45 deg. (200 m/s accelerating to 350 m/s)

At 30k continue turning until the prograde marker is sitting on the horizon line of the nav ball.

NOTE: most people will say that these speeds/altitudes are off, these numbers are just to get you started in the new version, as you gain experiance with the new versions adjust to your own playing style.

[Xerxes]

^ Keep your angle of attack to less than 5 deg. and you should be able to prevent toppling effect however if the design is fundamentally flawed than the slightest turn is non-recoverable. I have built a few craft of non-efficient design and used excess gyros and even mass amounts of rcs thrusters to prevent spin when past the first layer of atmo. The only way I properly resolved it was to build rockets properly.