The HST Key Projects
Before astronomers submitted the first proposals for observing time
on the Hubble Space Telescope, the 1983 Space Telescope Advisory
Committee recommended that certain ``Key Projects'' be established.
These projects would focus on fundamental science objectives which
could only be carried out by the HST, but would require a large
investment in observing time. Defining these Key Projects was a way
of declaring a commitment to address these fundamental science issues
at the probable expense of other, smaller, projects. Initially, three
Key Projects were defined: the Determination of the Extragalactic
Distance Scale, the Quasar Absorption Lines Survey, and the HST Medium
Deep Survey. New Key Projects will be defined over the life of HST.
The main goal of the HST Key Project on the Extragalactic Distance
Scale is to measure the rate of expansion of the universe (known as
the Hubble Constant) to an accuracy of 10%. This is accomplished in
part by determining the distance to external galaxies with
unprecendented accuracy. The Hubble constant can be used to estimate
the age of the universe, and tells us something about the ultimate
fate of the universe. There is a Web page for the
Extragalactic Distance Scale, for those who which to pursue the
topic in greater depth.
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