"The biggest model rocket engine can *maybe* go 1000 feet. Prolly a lot less carrying another stage."
Hahaha. Common model rockets (up to D class engines) can go around 3000 ft. straight up. Multistage rockets, of course, go higher than single stage.
"Enthusiast" class rockets can use up to P engines (each letter is a doubling of total impulse, P is quite large). Amateurs have launched rockets in excess of 60,000 ft. altitude.
What makes these rockets essentially harmless is lack of a seeker and guidance system.
If the rocket in question was still producing a plume at 6,000 ft (as the article seems to imply) it would have had to have been quite large.
"Hahaha. Common model rockets (up to D class engines) can go around 3000 ft. straight up. Multistage rockets, of course, go higher than single stage. "
D engines will go 1000' with one pound of payload.
With 3 stages I would guess a lot less than that, not to mention the timing issues.
My point was that it is impractical.
High powered rockets, well, now your talking a different thing altogether...