This thing is cute. Before SpaceX announced Starship, I always expected the first fully-reusable orbital launcher to be very small, because it's so much easier and less expensive to make prototypes, and to come from a small, focused company.
It has some interesting features. Peroxide/alcohol is a well-recognized option for room-temperature propellants, but I hadn't heard before about dissolving propane in the alcohol to make it self-pressurizing. x.com/vbklgd/status/…
@vbklgd Be careful with that bipropellant combination. Peroxide/alcohol is not well-liked because they mix so easily into an explosive, though one could say this is also a problem with methane/oxygen. Non-water-soluble hydrocarbons have some big handling advantages.
@vbklgd If I remember correctly, @ID_AA_Carmack in his Armadillo days turned away from peroxide/alcohol propellants in part because of the hazard they'd pose if they leaked and mixed together.