Re: There is still legitimate concern about solar flares
"Water has long been proposed as a good solar storm cellar shield for spacecraft."
Any Hydrogen rich material would be a good shield from charged nucleons. Like the LH2 tank on the NTR graphics from Borowski and Co. at Glenn or the 6 external tank monstrosity proposed for VASIMR architecture by Lock-Mart New Orleans for Chang-Dias.
Sorry, I didn't mean to get into the whole VASMIR thing again...
