by kleinbl00

ie gravity

It is unclear why the rocket failed to return safely, as it had on earlier occasions.

I mean, statistics. When your plan includes a used steam boiler that's going to launch you to 5,000 feet so you can ride a balloon to the Karman Line so you can parachute down, the critical points of failure have multiplied well past the fault tolerance of your design.

An all-around bad outcome. The world would have been a much better place had he landed safely to say "whelp, looked pretty round up there."