Hipparcos

Acronym for High Precision Parallax Collecting Satellite, a scientific mission of the European Space Agency (ESA), launched in 1989 and operated between 1989 and 1993. It was the first space experiment devoted to astrometry, the accurate measurement of star positions, parallaxes, and proper motions. The Hipparcos Catalogue, a high-precision catalogue of more than 100,000 stars, was published in 1997 and is the primary realization of the ICRS at optical wavelengths (see IAU 2000 Resolution B1.2).

Source: IERS Technical Note 36: Glossary (PDF, 244KB, Not barrier-free file.) of the IERS Conventions (2010)