1: Development of autonomous robots. The light-time delay forces autonomy. 2: Possibility of discovering signs of prior life on Mars. 3: Baby steps on the wa

1: Development of autonomous robots. The light-time delay forces autonomy. 2: Possibility of discovering signs of prior life on Mars. 3: Baby steps on the way to developing a more robust space presence. I don't want to take the time to flesh these out. You could argue with all of them. You could grant them, and argue about cost/benefit. But ultimately, it's exploration, and there are no guarantees what will turn out, so arguing cost/benefit when benefit is unknown is not an analytical process.