The center of mass (in zero-g) or short CoM, also known as center of gravity (in gravity), is the middle of a grid, calculated by the physics engine.
Where is the center of mass?[]
Use the Info Screen to make the center of mass and Grid Pivot visible.
Every time you add or remove blocks when building, the CoM is recalculated accordingly. The center of mass can be outside any actual blocks if the grid center is hollow, because it's, for example, bell or donut or horseshoe shaped.
When you add blocks, the grid pivot stays but the center of mass moves
Why do I care about the center of mass?[]
The center of thrust and center of lift are less important in Space Engineers than in, say, Kerbal Space Program. In contrast to real-life physics, Space Engineers always applies thrust and rotation to the center of mass, even if the thrusters or Gyroscopes are placed asymmetrically, to avoid tailspinning.
- Knowing where the CoM is on a ship or rover is advantageous when placing gyroscopes close to the center for best rotation efficiency.[1]
- Place Parachutes Hatches symmetrically around the CoM prevents tilting.
- A mobile grid (like a rover or a tall rocket) in gravity will tip over when the CoM is unsupported.
Counterintuitively, Space Engineers does not realistically calculate tensile strength, so a static grid such as a bridge won't collapse, even if the CoM is massively under-supported.