Historical Videos/Channels
Dark Skies
Dark Skies is an educational aerospace history channel that talks about secret or forgotten planes, aviation projects, and more! It is a great way to learn about the many genius planes in the past that looked great on paper but were too expensive or unreliable in the skies above. Overall, it truly brings you to the realm of experimental aviation and gives you an insight into the origins of genius aeronautical design today.
Olaf Willocx
Yes, his name is spelled correctly, and yes, he is a fantastic YouTuber. He does an amazing job of explaining the basics of rocket propulsion. His videos also explain the difference between hybrid, solid, and liquid rocket fuels. If you are a cadet who is heavily interested in propulsion systems, this is the perfect channel for you.
Mustard
Mustard and Dark Skies are fairly similar channels. They both explain the history behind interesting aircraft that are not super well known. His videos are extremely interesting and educational and are very well made in terms of graphics and animations. Mustard is probably one of the best channels you could possibly watch to learn more about aviation history.
Animagraffs and Jared Owen
This is another truly amazing channel with regard to animation style and in-depth knowledge. Jack O' Neal, the creator of Animagraffs, does a fantastic job at explaining the engineering and mechanical works behind planes and other vehicles in general. Jared Owen does many of the same things. Their animations, channel style, and what they teach are very similar in general which is why they are paired together. If you are a visual learned of mechanics and engineering, these channels are for you.
Everyday Astronaut
Everyday Astronaut is one of the most famous space commentators. Has data and information-rich videos for those who love specific details about certain launches, engines, rockets, etc.
Scott Manley
Scott Manley has made many YouTube videos explaining recent events regarding rockets and has many Kerbal Space Program videos that will help give you an insight into what space travel is like and what it involves.
Greg's Automobiles and Airplanes
This is, frankly, an awesome channel. One who dives deeply into the technical elements of WWII aviation. A multi-hour-long series diving into the P-47's construction and armament, 30 minutes on the Wildcat's supercharging system, and a discussion of the engineering of the FW-190 or ME-163. All of this, you shall find, and much, you shall learn. Check it out!
Greg's Automobiles and Airplanes - YouTube
The Operations Room
Clear, chronological, fantastically engaging outlines of major battles during WWII - With maps to show the precise positions of units in 'real time', which I have no idea how he reconstructs. It's cool, nevertheless. He also has a second one, The Intel Report, which is equally cool.