When is weighing the rocket typically performed in the launch process?

Weighing the rocket is typically performed before the rocket is loaded with fuel to ensure accurate calculations of total weight and balance for flight. At this stage, the rocket's structure and components are fully assembled, allowing for a complete assessment of its dry weight. This step is crucial for various reasons: it helps in determining the rocket's performance metrics, such as thrust-to-weight ratio, and allows for adjustments to the design if necessary.

Having the weight calculated before adding fuel is vital because the weight distribution changes once the engine is loaded with propellant. This pre-fuel weighing provides a baseline for understanding how the rocket will behave during the launch sequence, especially regarding stability and aerodynamics.

The other stages mentioned, such as after assembly or immediately before launch, may not offer the same level of controlled variables needed for precise weighing. After pre-launch safety assessments could also be misleading, as those assessments typically focus on procedural safety rather than performance metrics. Thus, weighing prior to loading fuel is a standard procedure to ensure comprehensive preparation for a successful launch.