Center of thrust
The center of thrust (or CoT)is one of the three "centers" you can measure in the VAB and Spaceplane Hangar along with the Center of Lift and Center of Mass abbreviated CoL and CoM respectively. The CoT is the direction in which the thrust is acting and on which point the thrust is acting on. The CoT and center of mass should be in one line to minimize steering losses. It is important to note that the CoT is calculated based on ALL rockets on the craft Not just the rockets in any individual stage. As you activate/deactivate engines, detach engines, run out of fuel, and even dock with other craft, the CoM and CoT will change.
Reading the Center of Thrust
The Center of Thrust is used mainly to determine a rockets' behavior in flight by comparing its position to the Center of Mass. It's basically the same as the Center of Lift but this is generated by rockets rather than wings. If the CoT is left of the CoM then the rocket tilts right, to far right, and it tilts left. It behaves similarly if it is to far forward or backwards. The CoT should also be above the CoM as well, if it is below the CoM then the rocket will be top-heavy and be prone to tilting.
This is usually called pendulum rocket fallacy. In Kerbal Space Program such craft will be less efficient, as thrust vectoring needs to be applied to keep the craft pointing straight,and the thrust spent doing that is no longer available to push the rocket up like it normally would be. You can fix steering problems by adding rockets with thrust vectoring, adding an RCS, or adding control surfaces.
See also
- Center of lift
- Center of mass
- Pendulum rocket fallacy on Wikipedia
