CUBES (Cassegrain U-Band Efficient Spectrograph) will be the most efficient UV spectrograph on an 8-10m class telescope, exploiting the ESO VLT's higher telescope efficiency relative to the ESO ELT in ground-based UV wavelengths. The instrument provides wavelength coverage over a range of 300-405nm, with high instrumental efficiency (>37

ANDES,the high resolution spectrograph for the ELT, will work both in seeing limited mode and with Adaptive Optics (AO) correction. ANDES-SCAO is a single conjugated AO system working with natural guide stars, feeding the IFU coupled to the YJH spectrograph. The main science goal of the ANDES AO mode is the characterization of the exo-planet atmosphere in reflected light. Hence, the driving technical requirement for the AO system is the PSF contrast. The level of achieved contrast determines the number of exo-planets on which the instrument will be able to detect bio-signatures. The key challenge for the achievement of high contrast is the control of M4 petalling. Here, we present the current status of the ANDES-SCAO design, approaching the ANDES preliminary design review scheduled in fall 2024.

In the era of Extremely Large Telescopes, the current generation of 8-10m facilities are likely to remain competitive at ground-UV wavelengths for the foreseeable future. The Cassegrain U-Band Efficient Spectrograph (CUBES) has been designed to provide high instrumental efficiency ( > 37%) observations in the near UV (305-400 nm requirement, 300-420 nm goal) at a spectral resolving power of R > 20, 000 (with a lower-resolution, sky-limited mode of R similar to 7, 000). With the design focusing on maximizing the instrument throughput (ensuring a Signal to Noise Ratio - SNR- similar to 20 per spectral resolution element at 313 nm for U similar to 17.5 mag objects in 1h of observations), it will offer new possibilities in many fields of astrophysics: i) access to key lines of stellar spectra (e.g. lighter elements, in particular Beryllium), extragalactic studies (e.g. circumgalactic medium of distant galaxies, cosmic UV background) and follow-up of explosive transients. We present the CUBES instrument design, currently in Phase-C and approaching the final design review, summarizing the hardware architecture and interfaces between the different subsystems as well as the relevant technical requirements. We describe the optical, mechanical, electrical design of the different subsystems (from the telescope adapter and support structure, through the main opto-mechanical path, including calibration unit, detector devices and cryostat control, main control electronics), detailing peculiar instrument functions like the Active Flexure Compensation (AFC). Furthermore, we outline the AIT/V concept and the main instrument operations giving an overview of its software ecosystem. Installation at the VLT is planned for 2028/2029 and first science operations in late 2029.

Safety analysis methodically assesses potential hazards and risks associated with a system. It encompasses an evaluation of all potential sources of harm, including equipment failures, human errors, and external factors, aiming to identify vulnerabilities and devise risk mitigation strategies. This proceeding presents the safety analysis technique and results for the Cassegrain U-Band Efficient Spectrograph (CUBES), Very Large Telescope (VLT) class Instrument, with a specific focus on its safety aspects. Safety considerations are paramount in the design and development of any scientific instrument; one can proactively address any safety concerns and prevent any accidents or mishaps that could jeopardize the successful work of the Instrument. This analysis presents the assessment of the Severity, Probability, and Risk factors that each hazard has on humans, damage to products, or the loss of operations. CUBES, as a complex instrument, falls into multiple hazard classes, each with unique risks. Thus, this safety analysis plays a crucial role in ensuring the project's safe operation. The methodology used follows five steps in Assessing and Mitigating the risk. The obtained results give an insight into the effectiveness of the carried-out mitigation, reducing the unacceptable hazards from twenty-one to zero.

The first generation of ELT instruments includes an optical-infrared high resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion Echelle Spectrograph). ANDES consists of three fibre-fed spectrographs ([U]BV, RIZ, YJH) providing a spectral resolution of similar to 100,000 with a minimum simultaneous wavelength coverage of 0.4-1.8 mu m with the goal of extending it to 0.35-2.4 mu m with the addition of an U arm to the BV spectrograph and a separate K band spectrograph. It operates both in seeing- and diffraction-limited conditions and the fibre-feeding allows several, interchangeable observing modes including a single conjugated adaptive optics module and a small diffraction-limited integral field unit in the NIR. Modularity and fibre-feeding allows ANDES to be placed partly on the ELT Nasmyth platform and partly in the Coude room. ANDES has a wide range of groundbreaking science cases spanning nearly all areas of research in astrophysics and even fundamental physics. Among the top science cases there are the detection of biosignatures from exoplanet atmospheres, finding the fingerprints of the first generation of stars, tests on the stability of Nature's fundamental couplings, and the direct detection of the cosmic acceleration. The ANDES project is carried forward by a large international consortium, composed of 35 Institutes from 13 countries, forming a team of almost 300 scientists and engineers which include the majority of the scientific and technical expertise in the field that can be found in ESO member states.

ESO is in the process of upgrading one of the two FORS (FOcal Reducer/low dispersion Spectrograph) instruments - a multi-mode (imaging, polarimetry, long-slit, and multi-object spectroscopy) optical instrument mounted on the Cassegrain focus of Unit Telescope 1 of ESO's Very Large Telescope. FORS1 was moved from Chile to Trieste, and is undergoing complete refurbishment, including the exchange of all motorised parts. In addition, new software is developed, based on the Extremely Large Telescope Instrument Control Software Framework, as the upgraded FORS1 will be the first instrument in operations to use this framework. The new Teledyne e2V CCD has now been procured and is undergoing testing with the New Generation Controller at ESO. In addition, a new set of grisms have been developed, and a new set of filters will be purchased. A new internal calibration unit has been designed, making the operations more efficient.

We present a comprehensive overview of the collaborative efforts between the End-to-End (E2E) Simulator and the Data Reduction Software (DRS) team, focusing on the modeling of the U-band efficient Cassegrain spectrograph CUBES (ESO-VLT). The E2E model is a Python-based numerical simulator capable of rendering synthetic raw frames with high precision for both astronomical and calibration sources, starting from their 1-d radiation spectra up to the data produced by the detectors. Data from the E2E are processed by the prototype Data Reduction Software (pDRS), a Python library which implements the critical algorithms of the DRS. The PDRS performs wavelength calibration and extracts a 1-d spectrum from one or more reduced science exposures. The 1-d spectrum produced by the extraction routine is meant to be compared directly with the input spectrum fed to the E2E, actually "closing the loop" allowing for a real end-to-end assessment of the instrument capabilities.

FORS (FOcal Reducer and Low Dispersion Spectrograph), a multi-mode optical instrument mounted on the Very Large Telescope's (VLT) UT1 Cassegrain focus, gets a new look. The upgrade, known as FORS-Up (FORS-Upgrade), is being carried out by ESO and INAF-OATs, and includes, beside replacement of some optical components, the replacement of all the motors, the development of a new calibration unit, the adoption of a new detector, and the design of a control electronics based on the new ELT standards. The refurbishment work has started on the twin spectrograph FORS1, decommissioned in 2009 which was sent to the integration premises of the Astronomical Observatory of Trieste. After resuming the final design of the control electronics, this paper presents the PLC software implementation and the current state of the electronics integration with the new mechanics carried out at INAF-OATs. It also focuses on the ELT-based software and hardware solutions that have been adopted to meet the performance and safety requirements for the motorized functions that control the multi-object spectroscopy blades and the scientific exposure shutter, and require customized applications.

We present our numerical simulation approach for the End-to-End (E2E) model applied to various astronomical spectrographs, such as SOXS (ESO-NTT), CUBES (ESO-VLT), and ANDES (ESO-ELT), covering multiple wavelength regions. The E2E model aim at simulating the expected astronomical observations starting from the radiation of the scientific sources (or calibration sources) up to the raw-frame data produced by the detectors. The comprehensive description includes E2E architecture, computational models, and tools for rendering the simulated frames. Collaboration with Data Reduction Software (DRS) teams is discussed, along with efforts to meet instrument requirements. The contribution to the cross-correlation algorithm for the Active Flexure Compensation (AFC) system of CUBES is detailed.

In this paper, we present an overview of the software architecture for the ArmazoNes high Dispersion Echelle Spectrograph (ANDES) spectrograph, which has been developed as part of the recent System Architecture Review (SAR) held in October 2023. Our focus in this paper is twofold: we will detail about the control software and science tools that are set to be implemented. In particular, we provide a detailed view on how the ELT Instrument Control Framework has been effectively deployed to manage the complexities of a distributed instrument like ANDES. This entails a comprehensive discussion of the key architectural decisions we have made to meet the requirements of the project. Furthermore, we offer insights into the suite of science software that will be an integral part of the ANDES instrument. This includes the Exposure Time Calculator, Observation Preparation tools, and the Data Reduction Library. Finally, we provide an overview of the Data Analysis Software and the End-to-End ANDES simulator. These tools are crucial for processing and analyzing the data collected by the ANDES spectrograph.

Over the years, the European Southern Observatory (ESO) and a collaborative network of national agencies, institutes, and universities have continually upgraded the VLT and its array of telescopes, accompanied by various cutting-edge instruments and modules. Among the next generation of instruments, there is CUBES (Cassegrain U-Band Efficient Spectrograph), a mid-resolution spectrograph working in the UV ground-based band (300-400 nm). The work presented here is a proceeding on the CUBES hardware dependability and maintainability analysis up to the successful Preliminary Design Review (passed in December 2022) and some forthcoming updates from the ongoing Final Design phase. The work has been developed during the design phases in order to assess the dependability of the System, as part of the Very Large Telescope, and to verify the compliance with the System requirements. The goal has been the identification of the criticalities and potential failure and the definition of the basics of maintainability in view of the last phases of the project, with the aim to keep the system in operation with high availability. Furthermore, the document provides the functional analysis of the System, with a deep focus on the influence of the "degraded modes" on the reliability of the System. Reliability analysis plays a crucial role in ensuring the components of the CUBES project meet stringent performance expectations. It assesses the likelihood of component failure, providing insights into potential vulnerabilities and enabling proactive problem-solving to enhance overall system reliability.

The IBIS 2.0 project upgrades the Interferometric BIdimensional Spectrometer, which was operated at the Dunn Solar Telescope of the National Solar Observatory from 2003 to 2019, for installation at a new telescope at the Teide Observatory. The instrument combines two tunable Fabry-Perot interferometers, narrowband interference filters, a polarimetric unit, fast cameras, and a suitable control for the acquisition of high-resolution spectropolarimetric data of the solar atmosphere in the 580-860 nm spectral range with short exposures at high cadence under a remote control. The project underwent several phases. We provide an update on the design progress of the instrument and the status of the project, with special emphasis on the challenges arising from the vertical setup required by the new installation. IBIS 2.0 is expected to contribute to a better knowledge of plasma properties at different heights in the solar atmosphere.

FORS2 (FOcal Reducer/low dispersion Spectrograph) is a multi-mode (imaging, polarimetry, long slit and multi-object spectroscopy) optical instrument mounted on the Cassegrain focus of the UT1 of ESO's Very Large Telescope (VLT). Its versatility and large wavelength range (330-1100 nm) make it one of the most requested instruments at the VLT. To keep it operational for at least the next 15 years, the FORS upgrade project (FORSUp), a collaboration between ESO and INAF-OATs, was started: the twin spectrograph FORS1, decommissioned in 2009, has been sent to Europe and is currently undergoing a complete refurbishment in the integration hall of the Astronomical Observatory of Trieste. Once the upgrade is finished, FORS1 will replace FORS2 at the VLT. In this paper, we report the status of the work currently in progress on the control software: the original one is based on the VLT standards, and it is now being reimplemented within the new ELT (Extremely Large Telescope) software framework. New GUIs have been designed for FORS, which give the user in-depth control over the instrument; new templates for observational, engineering and maintenance procedures have been developed; hardware components have been configured, either as standard devices or as special devices (requiring customized solutions). The upgrade will ensure the continued operation of FORS and represent an invaluable testbed for the new ELT software framework.