значительно увеличивать

• Nuclear propulsion has vastly multiplied (or improved, or enhanced, or increased) the capabilities of the submarine.

• Service life of the tubes has been drastically (or greatly, or considerably, or substantially) extended.

• Useful life is increased considerably.

• The ease with which the nuclear force field deflects particles of lower energy adds greatly to the difficulty of working backward from the experimental data to the probabilities of alpha scattering.