And that dust — sharper-edged and more abrasive than Earth dust and sand, which is smoothed over time by weathering — posed a problem. On lunar missions, the astronauts returned to the LM covered in it. Wiping it off their helmets could scratch the surface, which made it harder to see. And dust would get into every nook and cranny in their suits, as well as on and in tools and instruments.

'There goes a fender'



But the dust-busting fenders only worked, of course, while they remained intact and attached to the rover. During the first EVA of Apollo 17, a hammer in astronaut Gene Cernan’s strap-on shin pocket caught on the rover’s right rear fender, pulling it off the vehicle.



“Oh – there goes a fender,” Cernan can be heard saying, chagrined, on recordings of the mission. “Oh, shoot,” Schmitt agreed, seconds later.



Fortunately, another vital component of Apollo was duct tape (innocuously labeled as simply “tape”). While Schmitt forged on ahead, Cernan taped the dislodged fender back into place. It was no easy task: “Good old-fashioned American gray tape doesn't stick to lunar-dust-covered fenders,” Cernan lamented; but eventually, he managed to reaffix the fender “for an indefinite period of time,” he predicted.



“I never thought I'd be out here doing this,” Cernan said of fixing a fender on the Moon, as he got back to work on the EVA’s main tasks once he’d finished. The two astronauts continued on in the rover to other sites; the duct-taped fender held for some time, but eventually it fell off in transit due to dust on the tape, which prevented it from holding the fender securely. While neither astronaut noticed the fender falling off, Schmitt did note an immediate increase in the amount of dust falling back on the astronauts and the rover as they drove, piping up with, “I think you have lost a fender. I keep getting rained on here [with lunar dust].”



Already on their way back to the LM, the pair carried on with only three fenders. By the time they reached to the LM, Cernan noted that the dust on the rover’s battery covers was thick enough to write in — much worse than the normal, thin layer of dust that would accumulate with a working fender. They needed a solution — and this time, it needed to include a new fender.