FORS-Up: Making the most versatile instrument in Paranal ready for 15 more years of operations

TL;DR

The FORS-Up project upgrades ESO's VLT instrument FORS2 with new technology and software, extending its operational life by 15 years and serving as a test bed for future ELT technologies.

Contribution

This paper details the comprehensive upgrade of the FORS2 instrument, including new detectors, software, and hardware, ensuring continued scientific productivity and testing ELT standards.

Findings

Successfully upgraded FORS2 with new detector and software

Extended instrument operational life by at least 15 years

Served as a test bench for ELT standard technologies

Abstract

The FORS Upgrade project (FORS-Up) aims at bringing a new life to the highly demanded workhorse instrument attached to ESO's Very Large Telescope (VLT). FORS2 is a multimode optical instrument, which started regular science operations in 2000 and since then, together with its twin, FORS1, has been one of the most demanded and most productive instruments of the VLT. In order to ensure that a FORS shall remain operational for at least another 15 years, an upgrade has been planned. This is required as FORS2 is using technology and software that is now obsolete and cannot be put and maintained to the standards in use at the Observatory. The project - carried out as a collaboration between ESO and INAF-Astronomical Observatory of Trieste - aims at bringing to the telescope in 2023/2024 a refurbished instrument with a new scientific detector, an upgrade of the instrument control software and electronics, a new calibration unit, as well as additional filters and grisms. The new FORS will also serve as a test bench for the Extremely Large Telescope (ELT) standard technologies (among them the use of programmable logic controllers and of the features of the ELT Control Software). The project aims at minimising the downtime of the instrument by performing the upgrade on the currently decommissioned instrument FORS1 and retrofitting the Mask Exchange Unit and polarisation optics from FORS2 to FORS1.