> Could this be used as initial propeler to raise a rocket high enough to use this technique as a "first stage engine" in flying object out into space?
I don't really see how. You'd need some kind of gigantic and fairly stable platform to shoot the jet from - if you have that, it would be easier to just launch the rocket from that.
And you're forgetting the fact that we seldom just launch stuff "into space" - we want it in orbit. Only about 20% of the delta-v budget of a typical launch to orbit is the "vertical" component, the large majority is spent on attaining angular ("sideways") velocity. So you'd be doing an awful lot of work just to cut down that 20% by, say, a quarter - it's simply not worth it.
I don't really see how. You'd need some kind of gigantic and fairly stable platform to shoot the jet from - if you have that, it would be easier to just launch the rocket from that.
And you're forgetting the fact that we seldom just launch stuff "into space" - we want it in orbit. Only about 20% of the delta-v budget of a typical launch to orbit is the "vertical" component, the large majority is spent on attaining angular ("sideways") velocity. So you'd be doing an awful lot of work just to cut down that 20% by, say, a quarter - it's simply not worth it.