Yeah, I guess I understand that, it just seems like most things that aren't a design failure are unlikely to affect more than one orbiting telescope. In other

Yeah, I guess I understand that, it just seems like most things that aren't a design failure are unlikely to affect more than one orbiting telescope. In other words, to return to your example, it seems unlikely to me that a collision would happen to more than on telescope ever, let alone in a time window too tight for a third (or fourth, etc) telescope to be built and launched. (and, anyway, it looks like you are right: this is all budgetary anyway, so whatever)