The thing was, the moon buggy was churning up the fine powdery moondust whaich was contaminating their onboard bug stuff, so with some paperwork they had lying around (!) and DUCT TAPE they fixed this gizmo which kept the dust down. What do they call them on bikes, like mudguard attachments? Oh and it's here,
http://antwrp.gsfc.nasa.gov/apod/ap011110.html if you'd enjoy a closer look.