FORT IRWIN, Calif. — Spc. Christopher Frank donned bright white goggles that stuck out against the desert valley. The scouts were surrounded by rocky hills like the ones they had been humping new drone gear up over the past few days. It would be over 100 degrees by the afternoon, and the soldiers were already covered in a thin film of dirt and sweat. Frank sat on a bulky black case, looking through the first-person view headset. He told Sgt. Gab…