PLATO (PLAnetary Transits and Oscillations of stars)1 is the M3 class ESA mission dedicated to the discovery and study of extrasolar planetary systems by means of planetary transits detection. PLATO Payload Camera units are integrated and vibrated at CSL before being TVAC tested for thermal acceptance and performance verification at 3 different test facilities (SRON, IAS and INTA). 15 of the 26 Flight Cameras were integrated, tested and delivered to ESA for integration by the Prime between June 2023 and June 2024, with the remaining flight units to be tested by the end of 2024. In this paper, we provide an overview of our serial testing approach, some of the associated challenges, key performance results and an up-to-date status on the remaining planned activities.

Digitally supported Systems Engineering, or Model Based Systems Engineering (MBSE) methodologies usage in full scale space science missions development in Europe is so far limited to a few cases and several factors limit a wider adoption: from lack of clear methodology, to limitations in tooling, to lack of clarity on contractual aspects. To tackle some of these limitations, a progressive implementation of MBSE practices in Science missions at the European Space Agency has been adopted, starting with the Euclid mission and continued with PLATO and ARIEL. We present an assessment of the experience in the PLATO mission with the usage of two main MBSE approaches: i) SysML model and ii) a Mission Parameters Database used for all performance and pipeline development. We review the lessons learned from the experience in Euclid, and the implementation in PLATO, and identify areas for development to reach standardization of practices in Europe.

A STOP (Structural, Thermal, Optical and Performance) analysis has been conducted on the camera units of the PLATO space mission. The analysis is devoted to the prediction of in-orbit performance metrics that could not be otherwise verified through direct testing. The analysis presented in this paper is restricted to the so-called "static cases" which provide a snapshot of a specified thermal condition. These are intended to evaluate the camera performance over the expected operational temperature range and at zero gravity. We hereby provide a description of the model, the requirements to be tested, the simulation strategy and the performance results.

PLATO (PLAnetary Transits and Oscillations of stars) is an M3 medium-class space mission in ESA's Cosmic Vision program devoted to detecting and studying a large number of extrasolar planetary systems. Its launch is planned for the end of 2026 from Europe's Spaceport in French Guiana. The PLATO Payload consists of 26 wide field-of-view Cameras, each observing a specific part of the sky, associated data processing units and power supply units. The 24 Normal-Cameras will provide a very high-resolution photometric measurement of light from a large number of stars, while the other two Fast Cameras will provide the colour information and will deliver the pointing data to the AOCS (Attitude and Orbital Control System). The Cameras will be integrated into an optical bench. Each of them is composed of the Telescope Optical Unit (TOU), the Focal Plane Assembly (FPA) and the Front-End Electronics (FEE). Currently, the serial production of the Cameras has already started facing critical key points, non-conformities and challenging problems. The status of the Product Assurance activities during the serial production for which the first flight models are being delivered after the AIT phase is reported.

In the context of PLATO Camera Subsystem development, it has been decided to take advantage of MBSE methodologies using Enterprise Architect by Sparx Systems as tool. A Local SysML Camera model for PLATO mission(1) has been built from different Excel spreadsheets, i.e. Verification Control Matrices, released by Subsystems. Same approach has been used for the Camera-System itself. The complete flow-down of requirements has been created in order to easily identify and monitor any impact on the design due to changes, deviations and non-compliances. The model can be updated at any time importing Excel spreadsheet while it can be used as source to export documentation needed during formal reviews, both as Word and Excel files. In addition, Model architecture and constraints have been created through Block Definition Diagram and Internal Block Diagram so that structure, interfaces as well as interaction between different items, can be easily identified and monitored at both System and Subsystem level.

Within the ESA PLATO M3 mission, the Telescope Optical Unit (TOU), i.e. the opto-mechanical unit, is a fully refractive optical system. The 26 TOU Flight Models (FM) to be delivered to the upper level, the PLATO Camera, make it a series production. The first Flight Models production faced many initial challenges from a Product Assurance point of view, mostly related to MAIT activities, while moving forward these challenges decreased. Discrepancies and non-conformities associated with, mainly, but not only, materials and processes, cleanliness and contamination control, safety, qualifications and validations, are the object of this proceeding. Thus, showing that serial production adds one more variable to possible failures, but at the same time, when root causes are corrected and solved, yields less difficulties in subsequent FMs MAIT and final production. Product Assurance, in monitoring the product in failure-proofing aspects, aims at mitigating criticalities and arranging for corrective and preventive actions that allow improving the likelihood of success of the mission.

Systems Engineering requires the involvement of different engineering disciplines: Software, Electronics, Mechanics (often nowadays together as Mechatronics), Optics etc. Systems Engineering of Astronomical Instrumentation is no exception to this. A critical point is the handling of the requirements, their tracing, flow down and the interaction with stakeholders (flow up) and subsystems (flow down) in order to have traceable and methodical evolution and management. In the Italian Astronomical Community, we are developing methodologies and tools to share the expertise in this field among the different projects. In this paper we will focus on the requirement management approach among different projects (ground and space based). We will analyses here different architectures and tools in order to provide to the end user a useful tool optimized for Astronomical instrumentation. The target and synthesis of this work will be a support framework for the Requirement management of the Italian Astronomical Community (INAF) projects.

Systems Engineering requires the involvement of different engineering disciplines: Software, Electronics, Mechanics (often nowadays together as Mechatronics), Optics etc. Systems Engineering of Astronomical Instrumentation is no exception to this. A critical point is the handling of the different point of view introduced by these disciplines often related to different tools and cultures. Model Based Systems Engineering ( MBSE) approach can help the Systems Engineer to always have a complete view of the full system. Moreover, in an ideal situation, all of the information resides in the model thus allowing different views of the System without having to resort to different sources of information, often outdated. In the real world, however, this does not happen because the different actors (Optical Designers, Mechanical Engineers, Astronomers etc.) should adopt the same language and this is clearly, at least nowadays and for the immediate future, close to impossible. In the Italian Astronomical Community, we are developing methodologies and tools to share the expertise in this field among the different projects. In this paper we present the status of this activity that aims to deliver to the community proper tools and template to enable a uniformed use of MBSE (friendly name Astro MBSE) among different projects (ground and space based,.). We will analyze here different software and different approaches. The target and synthesis of this work will be a support framework for the MBSE based system Engineering activity to the Italian Astronomical Community (INAF).

The TOU is the Telescope Optical Unit for the PLATO ESA mission, consisting of the opto-mechanical unit for each of the 26 Cameras of which PLATO is composed. The TOU is currently in the manufacturing, assembly, integration and testing (MAIT) phase for the Proto Flight Model (PFM) and for Flight Models (FMs). We present the design processes as seen from the Product Assurance (PA) point of view: PA aims at monitoring the design and addresses specific issues related to, among others, materials and processes (these shall be suitable for the purpose and for the life-time of the mission), cleanliness and contamination control (to limit the loss of optical performance), safety, monitoring of qualifications/validations. PA supports the project in failure-proofing aspects to mitigate criticalities, e.g. in the elaboration of non-conformances and deviations that can arise during the design and MAIT process, and/or are highlighted during the reviews for manufacturing, test, and delivery of the related hardware. PA ensures early detection of potential problems and risks for the TOU and arranges for corrective actions that aim at improving the likelihood of success of the mission.