Why do launch vehicles fly exclusively in an arc? To escape | Tech & Astronomy

Why do launch vehicles fly exclusively in an arc?

To escape the Earth's gravity, rockets are launched in an arc whose curvature increases with height. But why don't these vehicles fly vertically upward throughout the ascent?

In order to move steadily in orbit, the speed of the spacecraft must be equal to the speed with which it falls to Earth. This will prevent the ship from crashing, nor will it move too far away from the planet. However, below about 100 km, this is practically impossible, because air resistance will slow the ship down too quickly.

But above this boundary of space, or, as it is called, the Karman line, the ship can accelerate to a fairly high speed - more than 7 km per second. Due to this, after the engine is turned off, the device will drift in space at the same speed with which it falls, and, therefore, will rotate around the Earth.

Objects in orbit have the same mass as on Earth. They still have the same inertia and are also affected by the gravitational pull of the planet. They fall, but if they move away at the same rate as they fall, they will never fall to the surface of the Earth.

Launch vehicles are launched along an arcuate trajectory for the correct entry of the apparatus into orbit. At the first stage, the spacecraft moves upward, overcoming air resistance, and when the atmosphere becomes sufficiently rarefied above 100 kilometers, the rocket changes its trajectory in order to reach the desired orbit with minimal fuel consumption. If the launch vehicle is launched immediately at an angle to the horizon, the air resistance will be stronger and it is not certain that it will be able to overcome it and enter a stable orbit.