In light of the recent launches I was wondering why rockets launch straight up instead of taking of like a plane.
It seems to take so much fuel to go straight up, and in my mind I can’t see to get my head around why they don’t take off like a plane and go up gradually like that.
Edit – Spelling and grammar
Edit 2 – Thank you to everyone who responded. You have answered a life long question.
In: Physics
To get out of the atmosphere as fast as possible.
In theory you are right, a rocket on a planet with no atmosphere should ideally go sideways, after all 90% of the energy of getting something into orbit is horizontal speed, not vertical.
The issue is achieving that horizontal speed is difficult inside an atmosphere, so we launch up then slowly curve horizontally to eventually push our craft sideways.
There is a case for launching sideways though. Air breathing engines are generally more efficient than rocket engines, mainly because they give something to push back on. To propel something forward it must also push back on something else, a normal rocket brings its own fuel which it pushes back but a plane takes air from its surroundings and pushes it behind to accelerate.
There have been a few concepts of such a launch. For instance one solution has been strapping a rocket to the bottom of a plane and launching it from the plane at high altitude at decent speed and low atmospheric pressure to get in the way, this has been done successfully a few times but isn’t without its problems.
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