Very sad. However he went doing what he was into and really what more could you want?
My mate who founded Australasian Dirt Bike magazine died in an unfortunate accident in a desert race years ago and somehow I think he won dieing whilst doing his favorites thing.
I bet MM just got off on the whole rocket deal and took money from the gullible to finance his desire to ride a rocket..I doubt he thought the Earth was flat. These flat earthers are such an unfortunate crew basing their beliefs upon vague references in ancient writings that clearly were hopelessly uninformed...so nice to see someone other than faith healers capitalise on their stupidity...So happily he used their belief to finance his joy.
Here is a great video where scientists give flat Earthers a run and certainly give them far more respect than most sensible folk could ever extend.
https://youtu.be/Q7yvvq-9ytElex