How does the saturn v work?

Saturn V was designed around a single requirement: sending a fully fuelled Apollo spacecraft toward the Moon. To do that it stacked three stages, each with its own engines and tanks, on top of one another. At lift-off the vehicle weighed about 2,800 t, and more than 90 percent of that mass was propellant. Staging, discarding empty tanks as the flight progressed, was the only way to reach lunar transfer speed with the technology of the 1960s.

The first stage, the S-IC, burned refined kerosene (RP-1) with liquid oxygen in five F-1 engines that together delivered about 34,000 kN (7.6 million lbf) of thrust. It ran for roughly two and a half minutes and took the rocket to about 67 km and 2.7 km/s before separating. The second stage, the S-II, switched to liquid hydrogen and liquid oxygen, a lighter and more energetic combination, in five J-2 engines. It burned for about six minutes and brought the vehicle close to orbital velocity at around 185 km. The third stage, the S-IVB, had a single J-2 engine that fired briefly to complete orbital insertion.

Once in a parking orbit, the crew and ground control checked the systems. The S-IVB then relit for a second burn of about six minutes, the translunar injection, raising the spacecraft's speed to roughly 10.8 km/s. After that burn the command and service module separated, turned around and extracted the lunar module from the top of the spent stage. Guidance for the entire ascent came from the Instrument Unit, a ring of computers and gyroscopes mounted on top of the S-IVB, which steered the rocket by swivelling the outer engines of each stage. Thirteen Saturn V vehicles flew between 1967 and 1973, and none was lost.