Getting to orbit isn't about escaping gravity — it's about going fast enough horizontally that as you fall, Earth curves away beneath you.
Getting to orbit isn't about escaping gravity — it's about going fast enough horizontally that as you fall, Earth curves away beneath you.
An orbit is not 'above gravity'. At 400 km, gravitational acceleration is still ~8.7 m/s². You're not outside gravity; you're moving sideways so fast that the curved Earth falls away as fast as you fall toward it.
A rifle bullet travels about 1 km/s. An orbital spacecraft travels 7.7× faster. The energy required scales with velocity squared — which is why getting to orbit is so expensive.
Most propellant is consumed in the first few minutes — fighting two forces that only exist at low altitude.
This is why early tracking of a rocket shows a horizontal acceleration phase — the vehicle is spending most of its energy building sideways speed, not going up.