From the various communities I've been in contact with, hydrogen is best for anything that is just one giant skyscraper with a tiny-tiny little habitation and cargo block at the front end.tpkc_klick wrote: ↑Wed Mar 03, 2021 9:19 pmThe "best" option for a propellant is usually extremely case-specific, and depends heavily on the mission and operational goals of a vehicle, the logistical and industrial capacities of whoever is building and fueling it, and the design and configuration of the engine itself. Thus, there is no one "best" proellant for any given type of engine (so of course people have pointless internet nerd fights about it...)GrandAdmiralFox wrote: ↑Wed Mar 03, 2021 5:14 pmGood to know. Then again I keep in touch with various SciFi communities and you wouldn't believe the flame wars that asking what is the best propellant for a nuclear rocket would be.
I do think hydrogen has one huge advantage as reaction mass for an advanced space-faring species like the Loroi: its easy to get in huge quantities from just about anywhere (most abundant element and all that). It also bonds nicely with other elements to form things like water, which does things like freeze, making it easy to collect. It means that keeping ships supplied with hydrogen reaction mass practically can't turn into a strategic choke-point, which is a risk for potentially more efficient but much rarer proellant (like xenon, for example).
Unless you've got Battletech fusion engines that spew their hydrogen at what looks like FTL speeds.
Once you get out of the world of solid NTRs (i.e. fission reactors with one end being the rocket end and one where the propellant goes), it is generally agreed that water is the best general propellant, especially if you're wanting to go more than microgravities. Methane/Decane do better but that comes at the risk of carbon fouling, which is bad.
Playing Children of a Dead Earth for over 150 hours gets you to understand the subtleties and frustrations of solid-core NTRs and chem rockets... and gives you a good idea of how tyrannical the rocket equation (and thus rocket construction) is. That is despite the fact that there are still bugs and exploits to fix.