* Weight changes: Weight is the force of gravity acting on an object's mass. Since the moon's gravity is about 1/6th that of Earth's, a spaceship would weigh less on the moon.

* Mass remains the same: Mass is the amount of matter in an object. It doesn't change with location. So, the spaceship's mass would be the same on the moon as it is on Earth.

Therefore, the measurement that remains the same is the spaceship's MASS.