They understood the risks; there is no question in my mind that they didn’t. I think they were bored with what life could offer them with that much money. At a certain point you really can basically experience it all. Instead of going on a tested rocket ship; they gambled the ultimate wager. Their life or bragging rights. Image the tale you could tell coming back from the journey in such a rigged tube; or the publicity of your fatal demise and making a “historical” moment regarding it. The world was watching. Darkly their death reads better than any final service of passing or headstone does.