It was expensive lesson but "Gravity Probe B" was not a failure - NASA and science simply learned there is no "frame-dragging" or "space-time fabric" and Einstein's General Theory has another weakspot (his "Principle of Equivalence" is the big one). They blamed their failure to find it on the noisy sun and asked for more funding but NASA said, "no way".

Science still holds on to the concept that matter moves "relative to space" - which it does not. Matter's motion, relative to space, is zero. Michelson and Morley proved this over a hundred years ago but they nor any of the other scientists accepted the results of their experiments (they thought their experiment was a failure too, but it was not) and made up all sorts of ad hoc excuses to justify their decisions. Einstein said "it was irrelevant but it is not - far from it.

I predict that the Higg's particle will be another expensive test failure - when they cannot find it.
Actually, a body's inertial mass increases when a force is exerted on it and it rises to a higher energy level, relative to space,(its "space energy level" rises). A body's inertial mass is simply its - energy level relative to space. It does not need a Higg's particle.

Don Hamilton
http://novan.com/mind.htm