Why are NASA's new astronaut candidates called the 'Eight Balls'?

... . Pro Mujer cofounder Lynne Patterson stands next to a photo mural in the Latin American microlender's New York headquarters. Women in developing countries 'hold the key' to their futures, Lynne Patterson says. Her nonprofit Pro Mujer helps them ...

http://www.csmonitor.com/Science/2013/0821/Why-are-NASA-s-new-astronaut-candidates-called-the-Eight-Balls-video