  We present a bibliographic analysis of Chandra, Hubble, and Spitzer
publications. We find (a) archival data are used in >60% of the publication
output and (b) archives for these missions enable a much broader set of
institutions and countries to scientifically use data from these missions.
Specifically, we find that authors from institutions that have published few
papers from a given mission publish 2/3 archival publications, while those with
many publications typically have 1/3 archival publications. We also show that
countries with lower GDP per capita overwhelmingly produce archival
publications, while countries with higher GDP per capital produce guest
observer and archival publications in equal amounts. We argue that robust
archives are thus not only critical for the scientific productivity of mission
data, but also the scientific accessibility of mission data. We argue that the
astronomical community should support archives to maximize the overall
scientific societal impact of astronomy, and represent an excellent investment
in astronomy's future.
