Thoughts on hovering rocket.

I have been doing alot of thinking on the propulsion system for the hovering rocket.

My first idea was a a rocket tethered to a compressor. After talking to a nasa guy at aerosapce futures this turned out to be impractical because the relatively rigid tether would mess up the vehicle dynamics to the point where its no longer an exercise in hovering but fighting the tether.

My second idea was to use steam. There would be a boiler which would be filled with a small amount of water. Heat would be applied until the steam was superheated at about 500*c. The heat would be taken way and the rocket could be turned on.

There are two main issues with this idea. First and more importantly any motor gimballing would involve some sort of flexible pipe to conduct the steam. This is not practical. I could possibly make some sort of universal fluid joint, but that would be quite complicated.

Vanes in the exhaust are definitely possible

I am really thinking that i will just use compressed air with an internal tank. I may only got 5 seconds of hover time but as a proof of concept its definably the easiest.