Complex sentence: From the rocket equation, the delta-v of a rocket is logarithmically related to the mass ratio of the vehicle, minimising the delta-v budget as far as possible is usually very important to avoid the necessity for infeasibly big and expensive rockets.
Split into simpler sentences: From the rocket equation, the delta-v of a rocket is logarithmically related to the mass ratio of the vehicle. Minimising the delta-v budget as far as possible is usually very important to avoid the necessity for infeasibly big and expensive rockets.