Ellen Wilson: Lives have been lost, and, honestly, probably more will be lost. But every one of us knew the risks before we joined, the toll it takes on us, and on the ones we love. But we all signed up just the same. It's the price we pay to push forward to explore the universe and wander into the unknown. Pushing ourselves to the limits of what's possible. Are there sacrifices that have to be made? Of course. But sacrifice is a part of any journey. It's like those caravans, the wagon trains that crossed our country a hundred years ago in search of a new home. Or the ships that sailed across the Atlantic in search of a new world. Taking on these great challenges against great odds that's what makes us human. Remember, we chose to go to the moon not because it was easy but because it was hard. So, yes. Yes, I think it's worth it. Because no matter how hard it is now, when we look to the future, we can see that things can... they can get better. I do believe that.