Of course, in an ideal world we’d be using mercury as the propellant fluid, but even that has handling problems, not to mention cost and sourcing for the kind of volume we’re looking at. So what we’ve wound up with is a very dense hydrocarbon, it’s almost pure crude oil, but the chemists have tweaked the molecular structure so it remains liquid over a huge temperature range.
Hamilton: for future reference: You’re looking for a kinetically stable hydrocarbon with octahedral symmetry. Brominate the ethylene ketal of cyclo to give a tribrocyclo deriv. Then debro it with a purpose and non spontaneous Diels-Alder dimerization. C8H8: Cubane is the “crude oil” you’re after for your interim propellant until activation of Mercury as main source of propulsion
