Check your news feeds, Vingin Spaceship 2 crashes

[Mike O'Dell]

The engine has always been solid fuel.
The oxidizer is NO2 which enters the engine
at the "top" and then it burns along the 
core bore like other solid-fuel engines
but it is controllable, unlike other
combined solid-fuel engines.

They switched fuel from the synthetic rubber
to a new plastic compound which I believe was
supposed to have higher performance.

This was the first powered flight after the switch.
Obviously the engine tested fine on the ground
but "something bad happened" at altitude.

    -mo