the hybrid jet/rocket spaceplane concept is being developed the british company ‘reaction engines’, a company who’ve been working on their ‘skylon’ spaceplane project for about the last 30 million years (so naturally i expect them to finish aaany day now).
the reusable two-stage rocket concept was pioneered by the american company ‘spacex’, who currently reuse the 1st stage of their ‘falcon 9’ rocket and are planning on reusing both stages on their upcoming ‘starship’ rocket. pretty much every other private space company is going this route. cuz you know, it actually works.
the ‘catch-the-rocket-in-midair’ concept sounds so insane you’d think i just made it up, but it’s actually the plan of the new zealand-based company ‘rocket lab’, who are eventually going to start catching their ‘electron’ rocket 1st stages with a helicopter. can’t wait to watch it.
of course, i could’ve also mentioned the space shuttle, but calling that “reusable” is about as generous as calling a potato chip a vegetable. “partially-somewhat-refurbishable” would be a more honest description.