On this date 20 years ago, four women and four men began their 2-year stay inside the self-contained "Biospehere 2" outside Tucson, Arizona. I remember thinking at the time that the whole endeavor, a stated focus of which was to develop technology for future space colonization, was sort of flaky. Nonetheless, that original mission ran as planned from 1991 to 1993. But then the problems began. A second mission in 1994 lasted only six months before being terminated prematurely in what Wikipedia termed, "a dispute over the financial aspects of the project." (Hard to believe that a gigantic self-contained environment the size of two football fields, enclosed in glass in Arizona, might burn rapidly through $200 million in venture investment and then run into money problems.) While the 'Biosphere 2' remains open to tourists today, no other 'missions' have ever been mounted there. In 2007, the property was sold for $500 million to a residential developer. But the financial crisis has provided a de facto 'stay of execution' to date, apparently.