I inadvertently built one of these as a kid. I did something wrong with the "launch wadding" and maybe the nosecone. When the recovery stage blew and it was suppose to blow off the nose cone and deploy the parachute, it just blew up the whole rocket and then it nosedived into the grass of the park.
I recall having that exact experience as a kid. It was equally disappointing (it definitely ruined the rocket), and hilarious. Finding the remains of the rocket protruding from the earth, like a sad javelin sent from the heavens, still lightly smoking... priceless. Thanks for unlocking that memory, those were some great times.
Certainly a cool achievement. I struggle to see how you would scale up that pusher thing on the left side to an orbital class rocket. Also how does this technology fit into a world of re-usable and re-lightable rocket engines?