 Other tricky issues were control systems, since an MAV couldn't be flown like a model airplane and would have to be able to tolerate turbulence and wind gusts, and miniaturizing navigation, communications, and sensor systems, as well as ensuring that they didn't interfere with each other.DARPA specified that the payload would be no more than 15 grams.As extreme as MAV specifications were, a team under Ilan Kroo at Stanford University worked on an even more extreme design in the form of a centimeter-wide four-rotor mesicopter using microcircuit fabrication techniques.