one of my long time friends is a flat earther........

[Photon440]

I'll put this here to ponder: Why do we need Saturn rockets to escape the earth's atmosphere, rather than just let a plane fly at a straight horizontal plane vs. the earth ?

Rockets traditionally take off straight up just to get out of the atmospheric drag faster. If they flew horizontally, they'd be in thick air much longer. Even going straight up, the rockets aren't at full power all the time because of the air; they launch at full power, then throttle back as air resistance rises to prevent excessive loading (Max Q), then when they've reached thinner air they go to full power.

For example, for the Space Shuttle, Max Q was around 36,000 feet. Before that point, the main engines were throttled down to 65–72% of their rated thrust. Different designs vary, Apollo reached 43,000 - 46,000 feet before full power could be used.

Accelerating to the speeds needed to reach orbit while traveling horizontally would use much, much more fuel and create too much heat through friction.

 

[WileE]

Rockets traditionally take off straight up just to get out of the atmospheric drag faster. If they flew horizontally, they'd be in thick air much longer. Even going straight up, the rockets aren't at full power all the time because of the air; they launch at full power, then throttle back as air resistance rises to prevent excessive loading (Max Q), then when they've reached thinner air they go to full power.

For example, for the Space Shuttle, Max Q was around 36,000 feet. Before that point, the main engines were throttled down to 65–72% of their rated thrust. Different designs vary, Apollo reached 43,000 - 46,000 feet before full power could be used.

Accelerating to the speeds needed to reach orbit while traveling horizontally would use much, much more fuel and create too much heat through friction.nd why a plane would not gain altitude flying horizontally vs. the earth surface.

Gravity. You need to reach escape velocity to overcome gravitational force.