The M2 secondary mirror of the Vera C. Rubin Observatory, scheduled to be commissioned on-sky in 2024, will be the first active secondary mirror of 3.5m diameter in operation. Its substantial dimensions and advanced functionalities place it in league with the secondary mirrors of the upcoming 30m class telescopes. Characterizing its performance serves as a critical step towards comprehending and controlling the optics of the next generation of Extremely Large Telescopes (ELTs). This study focuses on testing and validating the M2 cell in the Observatory’s integration hall and at the Telescope Mount Assembly (TMA). We also report on the integration steps of the M2 cell onto the TMA itself, including installing the light baffle. During the testing campaign, the M2 cell is equipped with an aluminum mirror surrogate for safety reasons regarding the glass mirror. To ensure integrity when the thin glass mirror (10cm) is installed onto the telescope, the M2 support system must be actively controlled during any M2 cell movement. This prompted the development of a dedicated control system to enable closed loop mode for transporting the M2 cell with the glass mirror from the integration hall to the telescope. The tests in the integration hall were conducted with the M2 cell mounted on a rotating cart, allowing different orientations with respect to gravity as it will experience on the telescope. Upon reaching the telescope, static and dynamic tests are conducted at progressively higher telescope performance, increasing slewing speed, acceleration, and jerk. A significant novelty introduced by Rubin to astronomical instrumentation is the Verification & Validation architecture as part of the model-based Systems Engineering approach where requirements, test procedures and executions are merged into an interlaced and dynamic flow. This report presents the experimental results from the distinct test campaigns covering a wide range of M2 cell functionalities. These include characterization of actuator behavior in terms of maximum stroke and force limits, evaluation of closed-loop (active) and open-loop (passive) support system operation for the M2, system settling time and Force Balance response to different slewing speeds of the telescope.
The Vera C. Rubin Observatory is an integrated survey system, currently under construction in Chile, to accomplish a 10-year optical survey of the southern sky. The 8.4-meter Simonyi Survey Telescope mount is nearing completion and undergoing final verification and performance testing. Since the system is optimized for etendue, the telescope mount slewing performance is particularly critical to overall survey efficiency. For example, this high performance mount is required to slew 3.5 degrees, on the sky, and settle in a 4-second period. Here an account of the mount subsystem is presented and selected dynamic performance results from on-site testing are described.
The Vera C. Rubin Observatory is reaching the final stages of its construction and integration, advancing towards its 10-year Legacy Survey of Space and Time (LSST). One of the key milestones was the installation of the M1M3 Mirror Cell Assembly onto the Simonyi Survey Telescope’s (SST) Telescope Mount Assembly (TMA). The Cell Assembly actively supports the primary/tertiary mirror (M1M3), playing a crucial role in maintaining the glass safe and ensuring image quality. However, before the mirror glass installation, the Cell Assembly was installed on the TMA while supporting a steel surrogate M1M3 mirror. This surrogate closely mimics the glass mirror’s mass, center of gravity, and geometry. The M1M3 cell and surrogate were tested under conditions that simulate rapid field changes in the sky, which are essential for the observatory’s ambitious sky mapping schedule. These tests, extending from 1-100% of designed telescope slew velocities/accelerations, assessed the M1M3 active mirror support system, including the force balance system’s performance, the hardpoint behaviors, and the efficacy of the pneumatic figure control actuators. Preliminary results suggest the system meets operational requirements, ensuring safety and effectiveness at full speed.
The Vera C. Rubin Observatory is nearing completion, and we are embarking on a campaign to optimize the image quality during its upcoming 10-year optical survey. Here, we present the tools and methods we are implementing to disentangle and quantify the different sources of image degradation, as well as our plans to correct and mitigate as many of these different contributions to seeing as possible. The tools include an on-site Differential Image Motion Monitor (DIMM) for measuring atmospheric seeing, multiple 2D and 3D sonic anemometers for measuring in-dome wind speed and turbulence, and direct dome seeing monitors. We also implement a guider mode that allows data to be taken at 9Hz over small regions and a stuttered and streaked imaging mode that allows us to measure mount tracking and jitter and perform atmospheric tomography. Additionally, we use curvature wavefront sensing to estimate the residual wavefront error to support the telescope’s alignment and focus. This is the same algorithm that we will use for the Simonyi Survey Telescope. Many of these tools, as well as additional techniques to quantify the contribution of astigmatism to seeing, have been tested at the Auxiliary Telescope (AuxTel). This 1.2m telescope acts as a pathfinder for the Rubin Observatory. We present initial results and the creation of an image quality budget table for AuxTel to characterize and monitor significant sources of image quality degradation. We then discuss plans for implementing these techniques on the 8.4m Simonyi Survey Telescope.
The shipment of the LSST Camera from SLAC National Lab in California to Rubin Observatory in Chile was completed successfully in spring 2024 after extensive road and flight testing of the Camera’s shipping container. Prior to final shipment, two local driving tests and one full test shipment from California to Chile were completed with a mass simulator to validate the performance of the wire rope isolator system by collecting data on acceleration events and vibration modes. This paper presents the results from the second test drive as well as the final shipment of the LSST Camera and associated hardware to the observatory.
Ongoing improvement and roll-out of Diversity, Equity, Inclusion, and Accessibility (DEIA) best practices continue to be a key priority at the NSF National Optical-Infrared Astronomy Research Laboratory (NOIRLab) and the Rubin Construction Project. NOIRLab strives to be a leader in the astronomical community in the development of DEIA programs for employees, the scientific user community, and our communities where facilities are located. NOIRLab continues to build upon its foundational DEIA Strategic Plan. The DEI Officer leads the DEI Committee, which continues to strengthen the infrastructure of DEIA at the center. The flagship program of DEIA is the Broadening Participation program, which invites all 500+ staff at NOIRLab to spend up to 3% of their work time on DEIA or community engagement activities. This paper discusses all of the different opportunities that staff have to make DEIA a part of their work, and not a compartmentalized effort. We overview the work undertaken by the DEI Committee and allies throughout NOIRLab and Rubin to build DEIA into everything we do, aligning ourselves with the recommendations of the Astro2020 decadal survey, especially focusing on creating a new community astronomy model. Community astronomy recognizes astronomy participation as a two-way street, where the communities in which we occupy land and sites have equal participation in the science being done, and a culture of shared leadership is defined. We will also update on the establishment of the DEI Programs Manager position and an office of DEIA at NOIRLab.
The Rubin Observatory Commissioning Camera (ComCam) is a scaled down (144 Megapixel) version of the 3.2 Gigapixel LSSTCam which will start the Legacy Survey of Space and Time (LSST), currently scheduled to start in 2024. The purpose of the ComCam is to verify the LSSTCam interfaces with the major subsystems of the observatory as well as evaluate the overall performance of the system prior to the start of the commissioning of the LSSTCam hardware on the telescope. With the delivery of all the telescope components to the summit site by 2020, the team has already started the high-level interface verification, exercising the system in a steady state model similar to that expected during the operations phase of the project. Notable activities include a simulated “slew and expose” sequence that includes moving the optical components, a settling time to account for the dynamical environment when on the telescope, and then taking an actual sequence of images with the ComCam. Another critical effort is to verify the performance of the camera refrigeration system, and testing the operational aspects of running such a system on a moving telescope in 2022. Here we present the status of the interface verification and the planned sequence of activities culminating with on-sky performance testing during the early-commissioning phase.
The ongoing improvement and implementation of diversity, equity, and inclusion (DEI) best practices at facilities managed by the Association of Universities for Research in Astronomy (AURA) remains a key initiative driven by employees and management alike. AURA, as a leader in the astronomical community, develops and supports programs that advance our organizational commitment to diversity, broadens participation, and encourages the advancement of diversity throughout the astronomical scientific workforce.
Sandrine Thomas, Ranpal Gill, Alysha Shugart, Andrew Connolly, Richard Dubois, Felipe Daruich, Carol Chirino, Lauren Corlies, Robert Blum, Federica Bianco, Amy Davidson
The Vera C. Rubin Observatory is entering the final stage of construction, system integration, and validation. This is a very exciting and challenging phase of the life of an observatory. This phase requires a healthy workplace culture due to the significant pressure staff members may feel when trying to finish a project on schedule. At the Rubin Observatory, we value people’s diversity of experience, expertise, and perspective. We strive to have an inclusive, respectful, and fruitful collaboration between all our Rubin project personnel. Allies at Rubin work towards developing and maintaining a positive workplace culture that strives to increase motivation, improve happiness and satisfaction, and thus retains and attracts a diverse and talented workforce. We expect to continue these efforts in the transition to full survey operations and beyond. This paper describes initiatives that staff in the Rubin project have taken to achieve these goals.
Equity, diversity, and inclusion (EDI) in the workplace are essential to the success of a functioning observatory. The current climate among astronomical institutions with regards to EDI efforts is receptive. However, workplace demographics data, internal climate surveys among observatories, and representation in academic partnerships illustrate the strong need to strengthen efforts in EDI. Concrete initiatives are facilitated by strategic planning, solid goal setting, and accountability metrics. Astronomical facilities, managing entities, and their academic partners must have EDI as a central role of their operations in order to achieve and exceed their scientific goals, and to address the ongoing inequity that is strife in international astronomy. Since June of 2018, efforts of EDI have continued at facilities managed by the Association of Universities for Research in Astronomy (AURA), and goals have been established to implement the Diversity, Equity, and Inclusion strategic plan for the NSF’s National Optical-Infrared Astronomy Laboratory (NOIRlab) that was announced October 1, 2019. The objectives of this paper are: 1) to briefly overview studies illustrating the successes of EDI efforts, 2) discuss the current demographics of AURA and National Radio Astronomy Observatory (NRAO) employees, 3) to review the framework of inclusive organizations, 4) to describe the activities of grassroots EDI initiatives at AURA facilities since June of 2018, and 5) to discuss the process of writing the Diversity, Equity, and Inclusion strategic plan for NOIRlab. A report on the current status and important details from the process are presented.
Dedicated diversity and inclusion programs are important tools to utilize in a successful organization. Cross-disciplinary studies show that diversity contributes positively to overall productivity and innovation, in both profit and non-profit sectors. Diverse working groups are capable of producing better science, and creating an inclusive environment is essential to maintaining diversity in the workplace.
This paper first outlines studies of the measured benefits of diversity, and the different ways in which they manifest, in order to emphasize its importance. Demographics data from international astronomy organizations is presented to illustrate the current state of the workforce in observatories and within observatory operations. Finally, a much-needed focus is placed on inclusion in the workplace. We review why creating an inclusive environment is important for the success of maintaining a diverse organization. We discuss how different programs implemented at astronomical observatories contribute to creating an inclusive environment, and detail real-world examples of these efforts taking place in these institutions. The goal is that these strategies can be adapted to benefit other similar organizations.
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