[sci.space] Comments on the Astrometric Telescope Facility

ESG7@DFVLROP1.BITNET (11/22/86)

Paul Dietz is right (as usual) about the ATF being seriously compromised

by mounting it on the Space Station.  The thing is designed to be a free

flyer and **not** man tended.  Also its whole mission is based on high

precision pointing which is completely compromised by mounting it on the

Station.  I see this as a classic example of engineering ethics being

compromised for the sake of flakey, short term politics.  This is the

same sort of stupidity that NASA Headquarters was doing with the

Shuttle and ELVs.  If they can't find enough legitimate projects to

justify the Space Station then they need to reevaluate why they're

building the thing in the first place.  Paul did have one minor

glitch in his last posting (probably his source was faulty).  Paul

claimed that the ATF can detect earth-like worlds.  However the AIAA

1986 report "Astrometric Telescope Facility: Status Report" written by

the NASA Ames people running the project states:  The ATF can "detect

Uranus/Neptune-class planets (i.e. masses as small as 15 Earth masses)

through astrometric measurement of the star's motion."  ATF doesn't have

the resolution for earth-like worlds.  My own opinion is that the ATF

may actually be redundant, since the HST could in principle be

retrofitted with astrometry equipment after it has performed its primary

mission as currently configured.  Since the HST is designed to be

recovered, returned to Earth and easily modified, this strikes me as

a much more cost effective approach to the important work of astrometry.



                                Gary Allen