eso9808 — Organisation Release
Tests of FORS - the First Major VLT Instrument
3 March 1998
We continue the publication of video clips which illustrate the rapid progress of the VLT project. The present footage of the FORS (FOcal Reducer/low dispersion Spectrograph) instrument for the ESO Very Large Telescope was obtained by the ESO EPR Video Team during a recent mission to DLR (Deutsche Forschungsanstalt für Luft- und Raumfahrt e.V.) in Oberpfaffenhofen near Munich (Germany).
This video clip shows the FORS1 instrument for the VLT during the preparations for the acceptance tests in Europe. FORS (built under ESO contract in two copies by a consortium consisting of Landessternwarte Heidelberg and the University Observatories of Göttingen and Munich, Germany) will be the first scientific instrument to be mounted on Unit Telescope 1 of the VLT later this year. With this instrument astronomers will be able to observe extremely faint objects ranging from the most remote quasars near the edge of the observable universe to the enigmatic tiny bodies in the outer part of our solar system.
Due to its versatile design, FORS can be used in various observing modes, like recording images or spectra. These capabilities demand a great optical and mechanical complexity and careful construction and alignment. This is not trivial in an instrument consisting of three major parts containing the delicate optics and mechanics. Fully assembled, they measure 2.5 metres in length and weigh 2.3 metric tons.
As the instrument will be attached to the Cassegrain focus (behind the giant 8.2-m main mirror) of the VLT, it will move with the telescope when following the daily motion of the sky and simultaneously has to rotate around its axis. This double motion is being tested on a specially designed telescope simulator, presently located at an assembly hall of DLR in Oberpfaffenhofen.
For further technical information and more images, please visit the FORS home page
More information is available at the ESO website about the VLT project. Note also that preparations are now being made for the UT1 First Light Event that will occur within a few months.