Final answer:
The Saturn V rocket, with its powerful engines designed to launch heavy payloads, made it possible to achieve the final speed required for orbit. This, together with mass reduction techniques and the use of airplanes for initial launch stages, revolutionized rocketry and space travel.
Step-by-step explanation:
The invention that made it possible to build rockets whose final speed is sufficient to put them on orbit around the Earth is the Saturn V rocket, which utilized powerful engines designed specifically for launching such heavy payloads into space. The Saturn V rocket, known for its role in the Apollo missions, used five of these engines and remains one of the most powerful rockets ever built. This technological leap, combined with other advancements in aerospace engineering, enabled not only the achievement of orbit but also the possibility of crewed lunar landings.
Rocketry also benefited from developments in the science of reducing the rocket's mass, which is crucial for achieving the high speeds necessary for orbital and beyond-Earth missions. Furthermore, innovative approaches such as launching rockets with satellites from airplanes provided an initial velocity boost and reduced atmospheric resistance, further contributing to the efficient reach of orbital speeds.