Fox2,

I noticed that the flight videos make it look like there is frost on
the launch area, maybe they are using LOX & alcohol for fuel.

Nope, I'm pretty sure it's just pure peroxide. Of the three companies
I know doing LOX/Alcohol lately (Armadillo, XCOR, and us here at
Masten Space Systems), none of our plumes have looked anything
like that. But all the guys I know who've done peroxide (John Carmack,
my boss Dave, some of the ERPS guys, etc) say it looks just like a
peroxide engine. Maybe that was steam, not frost?

But overall, pretty darned cool.

~Jon Goff