POP-FAME

The bacterial-grown fuel has been knocking around for about a week, which week I had better things to write about; I may as well get to it.

The backstory is that kerosene ain't the best fuel, being sooty. Also the best kerosene for rockets gives up 35 megajoules per liter (46.3 MJ/kg), which is nice, but not as nice as methane's 55 MJ/kg or maybe 55.5. (I don't care to look up the difference between CH₄ and LNG. But: 120% as good, by mass.)

In an analog to the metastable nucleus, metastable carbon compounds exist. These are "polycylcopropanated fatty acid methyl esters" which name Pablo Cruz-Morales and his crew have arranged to spell out POP FAME. That's 50 MJ/L. I don't see how they converted that to MJ/kg and, again, can't much be bothered but it looks like 1/70% = 143% as good as kero', by volume.

The same problem applies as applies to all metastable compounds - how do you even make it before it goes boom. Fatty acids imply that some organic life form might secrete it slowly and carefully... of which they're looking to Streptomyces. If they can ramp it up to industrial levels, a mature process for methane but not yet for a petri-dish.

Also if methane-driven engine melt is a consideration for the Raptor 2 then POP FAME's energy is that much % more a consideration. I suggest this for the supersonic sustained denotation also rotational, assuming that at least the energy isn't blasting through for as long. Manufacture should be easiest in microgravity itself.

At the end, nonreusable rockets should get a nicer massratio: lookin' to Uranus here on Falcon Heavy or maybe SLS. I dunno about SuperHeavy or Starship, both designed to come back down to Earth like the Falcon 9. Controlling that burn is going to be ... difficult. And won't the pickup barge or those tongs melt into pieces?