At the MIT Aeronautics and Astronautics Department’s Centennial Symposium, Elon Musk spoke.
He considers The Moon is a Harsh Mistress Heinlein’s best novel, and he wonders why rocket engines are always mounted on gimbals, and airplane engines never are.
I remember talking to a engineer or some such who said sci fi was a major source of inspiration for him and his friends. IIRC, Peter Thiel and/or his coauthor in “Zero to One” writes about how ‘Cryptonomicon’ by Neal Stephenson was mandatory reading at PayPal, where I guess Elon Musk also was. I’m sure sci fi authors love to hear that. :)
Rocket engines are gimbaled because directional control by airlerons and other surfaces is impossible in space. Aircraft engines aren’t because it is in air. Also, leaving out the gimbals saves weight. Rotary engines are still used in some small aircraft to save the weight of the cooling system.
Yes, rocket engines need to be gimbaled, because control surfaces don’t work in a vacuum, and airplane engines don’t need to be gimbaled, because control surfaces do work in atmosphere, but can we replace airplane control surfaces with gimbals? That’s an interesting question, and Musk suggests that we could, at least with electric engines.
I think some Su-27 had gimbals. There is also thrust vectoring in the F-22, if I am not mistaken.
Luckylucky beat me to it, but a lot of high-performance modern combat aircraft have thrust vectoring. I think what Musk is referring to, though, is engine gimbaling and vectored thrust as a total replacement for conventional control surfaces.
Always gimballed is incorrect. Look at Goddard’s first design and most of the early VfR designs.
I’m surprised the commenters haven’t yet mentioned the Harrier in the TVC world…