  Rough terrain locomotion has remained one of the most challenging mobility
questions. In 2022, NASA's Innovative Advanced Concepts (NIAC) Program invited
US academic institutions to participate NASA's Breakthrough, Innovative \&
Game-changing (BIG) Idea competition by proposing novel mobility systems that
can negotiate extremely rough terrain, lunar bumpy craters. In this
competition, Northeastern University won NASA's top Artemis Award award by
proposing an articulated robot tumbler called COBRA (Crater Observing
Bio-inspired Rolling Articulator). This report briefly explains the underlying
principles that made COBRA successful in competing with other concepts ranging
from cable-driven to multi-legged designs from six other participating US
institutions.
