The Hipparcos satellite in the testing facilities at ESTEC, The Netherlands, in 1988

Ten years ago, on 15 August 1993, communications with ESA's Hipparcos satellite were terminated, marking the end of a remarkably successful mission. Hipparcos, the first space astrometry mission, was a uniquely European project. Built for ESA by the European aerospace industry, and launched by an Ariane-4 rocket, the 1.4-tonne Hipparcos satellite operated from 1989 to 1993. Turning slowly on its axis and repeatedly scanning the sky on different slants, Hipparcos measured angles between widely separated stars, and recorded their brightness, which were often variable from one visit to the next. Each star selected for study was typically visited about 100 times over four years. The results from these observations were published in 1997 as The Hipparcos and Tycho Catalogues.

Hipparcos pioneered the techniques of space astrometry and placed Europe at the forefront of this scientific discipline. Gaia builds on this expertise to create a satellite capable of addressing one of the most difficult challenges in modern astronomy: to create an extraordinarily precise three-dimensional map of more than one billion stars throughout our Galaxy and beyond

To learn more about Hipparcos visit the Hipparcos website.

Image courtesy of ESA.

[Published: 11/08/2003 ]