On 8/3/2016 3:09 PM, Henry Spencer wrote:
Nevertheless, it is observed that propellant-boiling pressurization
systems for tanks initially pressurized with helium seem to work rather
better than would be expected from simple experiments attempting to
pressurize a subcooled liquid solely with its own vapor (which often
works very poorly indeed).
That said, I'm not aware of any controlled experiments that have
explored the details. Ground pressurization tends to use helium simply
to make it easier to maintain pressure during countdowns and delays, so
there's a shortage of data points without it. Actual data would be
welcome.
