I think it was a little over a year ago when the Mars Odyssey spacecraft discovered a great abundance of water ice just under the surface. One of the things they made a big deal about at the time was the supposed ramifications it would have on future human missions. It was said that the presence of water ice would make a human mission significantly quicker and cheaper because they could travel lighter. Yet ever since that time, I've never heard anyone factor this important discovery into the equation when I've read or heard people debate the topic of humans to Mars. Can anyone explain to me why that is? Wouldn't the water ice thing have some impact on the cost and length of the trip or would it only be beneficial after the first astronauts actually get there.