Intern in the Ground Systems Engineering & Innovation Department - Optical Technologies Section

## Location ESOC, Darmstadt, Germany ## Our team and mission ​​​The Ground Systems Engineering and Innovation Department is responsible for all the ground systems engineering and support activities required to support mission operations and implement innovation. ​The Department maintains and manages a full level of competences, technologies and services in all engineering disciplines related to ground systems, infrastructure, technology evolution and Engineering R&T and innovation. ​The Department provides expert support in these areas to the Directorate of Operations for all current and potential missions and leads, in the role of architect, ground systems evolution and innovation implementation in the infrastructure.

The Department is furthermore responsible for the overall technical standardisation coordination for the ground segment, in particular in the Management Council of the Consultative Committee for Space Data Systems (CCSDS). ## The Department is relying on the following domains of expertise - ​Ground Station Engineering; - ​Flight Dynamics and Mission Analysis; - ​Mission Operations Data Systems Engineering; - ​Navigation Support; - ​Multi-Mission Infrastructure – Ground Segment Integration and Testing.

Candidates interested are encouraged to visit the ESA website: http://www.esa.int ## 1) Topic 1: Measuring Space with Light: Satellite Retroreflector Arrays In-Orbit Validation Using Laser Ranging ​​Satellite Laser Ranging (SLR) is one of the most accurate space measurement techniques available today, enabling millimetre-level orbit determination and supporting a wide range of scientific and operational applications as precise orbit determination (POD), geodesy, Earth observation missions, navigation systems and space debris tracking.

Within this context ESA offers an exciting internship opportunity for students interested in optics, space systems, data analysis and laser technologies to contribute to the in-orbit validation of spacecraft Retroreflector Arrays (RRAs).

Using real mission data acquired from operational SLR stations, you will help analyse laser returns, assess optical performance in orbit, and develop innovative methods to characterise the behaviour of retroreflector arrays under real operational conditions. ​ You will contribute to the development and application of advanced techniques for the in-orbit validation of spacecraft Retroreflector Arrays (RRAs) through Satellite Laser Ranging observations.

Activities may include: - ​designing and supporting laser ranging observation campaigns for satellites equipped with RRAs; - ​modelling retroreflector array performance, including signal return characteristics, pulse spreading and observation geometry effects; - ​analysing high-precision laser ranging measurements to assess RRA performance and ranging accuracy in orbit; - ​comparing in-orbit observations with numerical predictions to validate optical models and mission assumptions; - investigating performance trends and anomalies caused by spacecraft attitude, thermal conditions or operational constraints; - ​developing data-analysis pipeline and visualisation tools to support the interpretation of SLR measurements; - ​contributing to technical reports and engineering assessments supporting current and future ESA missions. ​ ## What you will gain experience with - ​Satellite Laser Ranging systems and optical ground stations; - ​precision optical measurements and timing systems; - ​numerical modelling and simulation of optical payloads; - ​spacecraft orbit and attitude geometry; - ​scientific data analysis and visualisation tools; - ​real mission data from satellites operating in orbit. ​ This internship offers a unique opportunity to gain experience at the intersection of spacecraft engineering, optics, laser systems and data analytics, contributing to the validation of technologies that enable millimetre-level satellite positioning and support scientific and operational space missions. ## 2) Topic ​2: Optical Systems Performance Characterisation Using Astronomical Observations ​​Laboratory measurements and design analyses provide the reference expectations of the performance of an optical system.

However, the operational verification of an optical system requires the ability to assess its image quality and its system-level performance using observational data acquired under real operating conditions.

Stellar observations provide a unique and powerful means to evaluate the end-to-end performance behaviour of a telescope, enabling the characterisation of optical, geometric, photometric, tracking and dynamic performance directly from observational data. ​ ​The main objective of the internship is to develop a methodology and establish a comprehensive framework for the characterisation of optical systems from on-sky observations under real operational conditions and to identify measurable indicators that describe the overall performance of the instrument. ## ​The activities will address topics such as - ​field-dependent image quality characterisation; - ​optical distortion and geometric calibration; - ​throughput, vignetting, and photometric uniformity; - ​tracking accuracy and dynamic effects; - ​wavefront behaviour and wavefront error estimation; - ​field-dependent aberration characterisation; - ​focus and optical alignment assessment; - ​stability and repeatability of performance over time; - ​comparison between measured performance and optical design predictions; - ​definition of performance indicators suitable for operational performance assessment. ​ ## You will contribute to - ​analysis of observational datasets acquired under representative operational conditions; - ​development of methods and automated processing workflows for optical performance assessment; - extraction and visualisation of image quality, geometric, photometric, and stability metrics; - investigation of methodologies to characterise optical performance across the field of view; - ​generation of performance maps, statistical summaries, and trend analyses; - ​assessment of the impact of operational and environmental conditions on system behaviour; - ​comparison of observational results with optical models and expected performance; - ​consolidation of characterisation results into a coherent set of performance indicators and assessment products; - ​preparation of technical documentation and presentation of results; - ​verification and refinement of the optical model and optical prescription through comparison between measured performance and theoretical predictions. ​ ​This internship offers practical experience at the intersection of optical engineering, astronomical instrumentation, scientific computing, and performance verification, contributing to the assessment and validation of advanced telescope systems in an operational environment.​​ ## Behavioural competencies Result Orientation Operational Efficiency Fostering Cooperation Relationship Management Continuous Improvement Forward Thinking For more information, please refer to ESA Core Behavioural Competencies guidebook ## Education You must be a university student, preferably in your final or second-to-last year of university course at Master's level.

In addition, you must be able to prove that you will be enrolled at your university for the entire duration of the internship. ## Additional requirements The working languages of the Agency are English and French. A good knowledge of one of these is required. Knowledge of another ESA Member State language is an asset.

During the interview, your motivation for applying to this role will be explored. ## 1) Topic 1: Measuring Space with Light: Satellite Retroreflector Arrays In-Orbit Validation Using Laser Ranging - a strong interest in space and ground-based systems, optics, laser technologies, and satellite applications; - basic knowledge of optics, photonics, astrodynamics, spacecraft engineering, or scientif