A rocket can go vertically upwards in earth's atmosphere because
It is lighter than air
Of gravitational pull of the sun
It has a fan which displaces more air per unit time than the weight of the rocket
Of the force exerted on the rocket by gases ejected by it
A rocket can go vertically upwards in earth's atmosphere because
In accordance with Newton's $3^{rd}$ Law of Motion the exhaust exerts an equal and opposite force on the rocket which propels it upward enabling it to overcome the gravitational force of the earth.It flies along a path at an angle to the earth's surface which places the payload in an orbit around the earth.