What might happen if all motors of a cluster do not ignite at launch?

When a rocket is designed to utilize a cluster of motors, the intention is for all motors to ignite and provide uniform thrust. If all motors do not ignite at launch, the resulting thrust will be uneven. This imbalance can lead to a variety of issues during flight, one of which is that the rocket may not fly straight.

When one or more motors in a cluster fail to ignite, the thrust produced by the remaining active motors creates a torque effect that can make the rocket yaw or veer off course. This yaw can cause the rocket to spiral or tumble, depending on the degree of thrust imbalance, compromising its stability and trajectory. The resulting flight path may be unpredictable and erratic as the misalignment of forces can drastically alter its intended path.

This scenario emphasizes the importance of ensuring that all motors in a cluster are fully operational before launch, as failure in ignition can lead to significant deviations from the planned flight characteristics.