Building the largest machine in history, enabling cheap access to space, followed by the U.S. Navy SEALS developing a hardshell wingsuit to enable them to drop from Low Earth Orbit into combat.
Discovering that Saturn’s moon Iapetus is a starship; forming a compact with the builders to advance their technology; using artificial wormholes to rescue millions from a global Jihad; developing FTL starships, and pushing out into the Galaxy.
Each book stands on its own, but the books follow each other in sequence. Slingshot and The Daedalus Files take place in the same general timeframe a few decades from now. The Starchild Compact and The Iapetus Federation take place a couple decades later, using the space-launch-loop technology developed in Slingshot. The Iapetus Federation directly follows The Starchild Compact, but they can be read independently.