The first stage of the rocket consists of the following parts:
The oxidizer tank is that section of the rocket, where the oxidizer of the rocket propellant (see propellants) is stored. In the fuel tank, the fuel of the rocket propellant is stored.
In the centerbody section, the electronic parts of the rocket, which implement commands, are placed.
The engine used in the first stage of the rocket is Rocketdyne RS-27A. This engine burns rocket fuel (kerosene) with liquid oxygen to produce the necessary thrust. An RS-27A rocket generates 890,000 Newtons of thrust.
As stated earlier, the weight of the rocket at launch is enormous and a single RS-27A cannot alone boost such a huge object. So in addition to the RS-27A, the rocket has 9 strap-on solid propellant rockets.
On launching off the pad, more fuel needs to be supplied to the first stage engine so as to create more thrust. The fuel and oxidizer are mixed in the combustion chamber. The liquid oxygen keeps the main engine and its nozzle from getting too hot. At launch, the first-stage engine and six the strap-on boosters are ignited. The remaining three boosters will ignite when the first six boosters completely burn out. The spent casings of the boosters are jettisoned in sets of three within 1 to 3 minutes of launch.
Two small precision engines provide roll control while the main engine is burning. There are rocket sensors on the rocket. If they detect spinning or rolling of rockets, they stop the engines.
To make adjustments in the flight path gimbals controlled by fluid pressure are used.
About 4 minutes and 23 seconds into the flight, the main engine is cut off.
Now, within the next 20 seconds, the first stage will separate from the system. The first stage of launch is now over.