I am not a lawyer myself, but I think that my remarks concern a matter of legal importance. This is the question of the juridical height of the boundary between “air space” and “outer space”. We all agree that with the development of rocket techniques and of aviation, aircraft and other craft will continue to fly higher and faster than ever. For the aircraft of the future there seems to be no practical limit concerning the altitude at which they will fly. The X-15, a typical modern hypersonic aircraft equipped with a rocket motor, for example, can achieve an altitude of 160 km, and when provided with an appropriate booster, will reach a much higher altitude, perhaps 300 km, or even more. For this reason, I think that the best solution would be to set as a practical limit of “air space” the altitude at which we can effectively put our artificial satellites—the first true astronautical objects evolved by man This is an altitude of a little more than 200 km. But the density of the very rarified gas layer at this altitude varies with time, the geographical position, the changes in solar activity, and so on. And for these reasons, I propose that the practical limit of “air space” be set at an altitude of 200 km, irrespective of the geographical position and other factors.