Like Jeff Bezo’s… Uhh… Rocket… Don’t rockets need “fins” or “wings” to help stabilize or something?
In: Technology
Big rockets generally are able to steer by angling their engines. Also, if you’re going to actually orbit the planet, you don’t fly straight up, you pitch over sideways in what’s called a gravity turn, because getting into space is the easy part, to actually get into orbit you need to go sideways fast enough to miss the planet on the way back down, which takes much more energy.
If you check on Google images, you’d see his rockets had fins near the bottom to stabilise the rocket and act as control surfaces
If you’re surprised how small they are as compared to aeroplanes, the reason is that the thrust and lift of the rockets are coming from it’s engines pointed downwards (edit: and as another user mentioned, via engine gimballing). These engines are huge and have a lot of fuel to produce a lot of thrust. In aeroplanes, you are space limited so you need engines that provide thrust attached to large wings to generate lift, otherwise aeroplanes would either be huge or have little space for passengers and cargo in their current sizes
As a comparison, look up an image of a missile that is fired from military jets or vehicles – you’d also see that those have small fins for stabilisation and direction control, because the rocket motor is providing the thrust and subsequent lift
A different way of achieving the same result is by using attitude thrusters. Either the big rocket nozzles can move around a bit, or you have smaller rockets that can be pointed in different directions. I don’t anything about Bezos’ rocket itself, but if it does not have fins it will have this. It is probably more efficient anyway, because wings (or fins) only work up to a certain altitude; after that air is to thin to have an effect, so you will need attitude thrusters anyway.
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They do have relatively small stabilizer fins. The ones on Bezos’s New Shepard rocket are small, but they’re definitely still there. Also, a lot of the(suborbital) maneuvering and stabilization of rockets is done with engine gimballing, where the rocket engine physically swivels a few degrees to offset the thrust, especially once the atmosphere gets thin at high altitudes.
The rocket goes in the opposite direction to the exhaust product from the engine nozzle.
If that is directed vertically downward, the rocket will go vertically upward.
This can be modified by a gimbal mount on the engine to vary its alignment.
Fins and control surfaces which rely on airflow become useless once the craft clears the upper atmosphere, and this is typically achieved in a couple of minutes. After that, the fins are non-functional dead weight, and might as well not be there.
Bezo’s rocket relied on what is called gimballed thrusters for stability. Basically, the rocket can swivel on its mounting to point in whatever direction it needs to to turn or go straight up.
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