Many years ago, when I was the front desk evening week-end manager, I trained tour guides. They were inevitably high school students who were naturally apprehensive about giving a tour through a museum that primarily dealt with things they had not directly experienced. My advice to them was to go downstairs, identify their favorite artifact, then learn all they could about that piece. This exercise would eventually lead them to a deeper understanding of the whole story our museum tells. The cosmosphere's Russian collection is a big part of why the Hall of Space is so incredible. So, at number nine, is my personal favorite, the RD 107 rocket engines from the Soviet Union.