This sounds a lot like the continuing investigations of atmospheric radiation by students in the group EarthtoSky.net along with Spaceweather.com. The effort is largely funded by donations and purchases of items that are flown on the balloons.
They have been gathering data for several years I believe and recently conducted a study of radiation encountered by airline passengers on trans-continental flights.
Cool stuff that these kids are into. Maybe some of them will carry on their work with positions at NASA.
If I recall correctly, one of the hardest problems about getting humans to Mars is how to shield them from cosmic radiation. Usually stuff that shields radiation, like lead, is very heavy and very heavy stuff doesn't go very well with space travel.
Does it matter? A space ship is a closed environment, so presumably any water you start with will stay with you in some form or another. There may be some processes that turn it into a less usable form, but I imagine the majority of water would end up as either urine, essentially identical to water for the purposes of shielding, or sweat, which can be recovered as water through the life support system.
The problem is the massive amount of water you would need to create a protective shell. Getting it into orbit and accelerating the whole bubble towards Mars is very expensive and bringing it back probably impossible. But that's no problem if you're going to live on mars, right? Just bring enough water for irrigation.
I'm not sure of the procedures used to protect the Apollo astronauts, but it hasn't worked very well [0]. Though, NASA says that its too early in the process to make any conclusions [1].
The key conclusion of the study:
> They found the Apollo astronauts’ mortality rate from cardiovascular disease was as much as five times higher than for astronauts who never flew, or for those who flew low-altitude missions aboard the space shuttle that orbited a few hundred miles above Earth.
They have been gathering data for several years I believe and recently conducted a study of radiation encountered by airline passengers on trans-continental flights.
Cool stuff that these kids are into. Maybe some of them will carry on their work with positions at NASA.