A bunch of problems with the FAME/New Horizons dichotomy.

First of all: a FAME-like instrument can be flown at any time; & at least two similar instruments are already on the cards (Germany's DIVA & ESA's GAIA... the former will have lower resolution than FAME would have; the latter almost certainly much better, even allowing for likely downsizing from the current nominal design). This is not a statement you can sanely make of New Horizons; which flies cheaper in 2006 than at any other time & has a better chance of returning good science at Pluto/Charon the earlier it gets there.

Secondly: the instrument was canned because it couldn't deliver... the costs were blowing out badly; & the science return was reducing at the same time. New Horizons cut the costs that JPL claimed that a Pluto fast flyby required & improved the science return massively. I know who i'd be supporting on these circumstances; & it wouldn't be rewarding the FAME team's failure.

Thirdly: despite your personal interest in astrometry, this is basically a rather dull scientific mission with zero public interest; whereas the Pluto fast flyby has been kept alive - over the bureaucratic prejudices of NASA hq - by the public. Even astronomers have really struggled to defend FAME because it simply doesn't very much that is really scientifically exciting.

Fourthl: that cancelling FAME budget helped fund Kepler, another space telescope with an overlapping brief.

FAME isn't so much fleeting, it seems, as a mistake which has been belatedly corrected.

Robert.