Complex sentence: Project Thumper and Project Wizard were the earliest official efforts to develop an anti-ballistic missile (ABM) system, with the aim of shooting down V-2 like rockets in flight.
Split into simpler sentences: Project Thumper and Project Wizard were the earliest official efforts to develop an anti-ballistic missile (ABM) system. They were both concerned with the task of shooting down V-2 like rockets in flight.