A Tower in Space-Time — Laurence E. Dahners

This hard Sci-Fi novel is the fifth book in the Stasis Stories, a series of optimistic tales of technological innovation in the near future. They follow Kaem Seba, a young man with extraordinary math talents. With his friends, he's developing a device that allows time to be stopped within limited volumes of space-time. In this 5th story, Kaem's newfound physical fitness is letting him perform at an astonishing level in physical endeavors such as soccer, and martial arts. The company he, Arya Vaii, and Gunnar Schmidt founded to commercially develop his time-stopping discovery making money hand over fist. Currently, their profits come from their use of the phenomenal physical properties of a time-stopped segment of space-time to build rockets.But now they are building their space tower. Taking off at a thirty-degree angle from eastern Virginia, it's 200 kilometers long and a hundred kilometers high. By placing the interior of their spacecraft-and its passengers-in stasis they can accelerate launches at fifteen gravities, reaching orbital speeds before the craft leaves the rail! This lets them put payloads in orbit for a thousand times less than a rocket. The world, and some unscrupulous people, are turning to Kaem and his company to further our exploitation of orbital space...