4 ms·
They may have solved the LOX boiloff problem, but perhaps not.
by NortySpock 6y ago
They may have solved the LOX boiloff problem, but perhaps not.
- cookingrobot 6y agoEven if they need to refuel quickly, why not launch 6 starships for that mission? They’re planning to build lots of them aren’t they?
- jsmcgd 6y agoAs long as the crewed starship is fuelled in orbit not too long after the last tanker ship launched, then the amount of boiloff will be negligible. I suspect Spacex will develop cooling systems to re-liquefy any gaseous propellants as this will be more of a concern for the ~6 month mission to Mars.
- pharke 6y agoWikipedia[1] cites a 2010 study that gives a boiloff rate of 0.1% per day for hydrolox. Not sure if it would be less for pure LOX. Methane would remain stable so I wonder if there's a way you could balance the fuel load so that you can deliver only methane on some of the trips and then all the LOX in one trip to avoid having it hang around in orbit. [1] https://en.wikipedia.org/wiki/Propellant_depot#Feasibility_of_propellant_depots https://en.wikipedia.org/wiki/Propellant_depot#Feasibility_o...
- laverya 6y agoOxygen is the vast majority of the propellant mass, I'm afraid. Methalox is CH4+2O2->CO2+2H2O, so you need 4 Oxygen atoms for every Carbon atom (with Hydrogen being a rounding error).