Also, this article mentions that it is a tube of some sort: http://www.businessweek.com/articles/2012-09-13/elon-musk-the-21st-century-industrialist#p5 http://w

Also, this article mentions that it is a tube of some sort: http://www.businessweek.com/articles/2012-09-13/elon-musk-the-21st-century-industrialist#p5 http://www.businessweek.com/articles/2012-09-13/elon-musk-th...