RTG Plutonium Flag from The Martian - 2015

Perhaps the most unique flag in the movie The Martian 2015 - is the Plutonium marker flag.  It is pennant with metallic hoist.  The field is yellow.  It has a green spoke working symbol with a black skull and cross bones on the center.

Usually we see people in science fiction movies about Mars, planting flags on this planet.  But in The Martian we see our hero un-planting a flag.