Mechanical Engineer, Space and Defence FSO Systems

Business At Work; Paris; Hybride; EUR 40 000 - 60 000; Plein temps

Résumé du poste

Business At Work is seeking a Mechanical Engineer for Space and Defence FSO systems in Paris. You will own defined subsystems from concept to qualification, interfacing mechanisms, optics, and thermal control while ensuring alignment under launch and space conditions.

The role requires a Master’s in Mechanical/ Aerospace, space hardware experience, and strong CAD/FEA skills. Hybrid work with start 02 December 2026 and a Paris location offering challenging high-reliability projects.

Qualifications

• Advanced degree in mechanical/aerospace engineering.
• Experience taking hardware from CAD to test in aerospace/defense environments.
• Space-qualified hardware experience essential.

Responsabilités

• Design precision mechanisms and opto-mechanical structures.
• Perform or lead structural and thermo-elastic analyses.
• Ensure hardware maintains optical alignment under launch and thermal conditions.
• Define manufacturing, integration and test processes.
• Coordinate with suppliers and cross-functional teams.
• Lead environmental tests such as vibration and thermo-vacuum testing.

Connaissances

Analytical rigour

Hands-on engineering

Cross-functional collaboration

Documentation writing

Problem solving

Formation

Master’s degree in Mechanical/Aerospace Engineering

Outils

SolidWorks

CATIA

Creo

NX

ANSYS/Nastran

SimScale

Description du poste

## Job DescriptionOur client is an innovative and fast-growing technology company developing advanced optical communication and photonics-based systems for highly demanding applications.As part of the growth of its engineering activities, we are looking for a **Mechanical Engineer, Space and Defence FSO Systems.**Reporting to the R&D and Engineering teams, you will contribute to the design and development of high-precision opto-mechanical systems for Free-Space Optical (FSO) communication products operating in space and defence environments.You will work closely with the Lead Opto-Mechanical Architect and take direct ownership of defined subsystems throughout their full development lifecycle from initial concept and detailed design to manufacturing, integration, environmental qualification and test.This role covers the interface between precision mechanisms, opto-mechanical structures and thermal control. You will design hardware that must maintain optical alignment, withstand launch and operational environments, and deliver reliable performance over an extended lifetime without in-service adjustment.* **Precision Mechanism Design:** Design precision mechanisms including motion stages, bearing arrangements, preload strategies, actuation systems, encoder integration, launch load paths and cable-management solutions.* **Opto-Mechanical Structures:** Design optical benches, precision housings, isostatic and kinematic mounts, and structural assemblies from concept through detailed CAD modelling, fabrication drawings and fit-check activities.* **Thermal Design:** Define and optimise the thermal architecture of optical instruments, including heat dissipation paths, thermal interfaces, heater zoning, survival power, hot and cold cases, and athermalisation strategies for sensitive optical assemblies.* **Structural & Thermo-Elastic Analysis:** Specify, perform or steer structural and thermo-elastic analyses, including modal, quasi-static, sine vibration, random vibration, thermal distortion, line-of-sight stability and micro-vibration assessments. You will critically review simulation results and translate them into robust design decisions.* **Tolerance Management & Optical Stability:** Build and close mechanical tolerance chains from individual parts through to optical alignment requirements. Assess gravity-release effects, thermal expansion, assembly variations and their impact on optical performance.* **Space Mechanism Qualification:** Define and support the qualification of mechanisms, including torque and force margins, bearing performance, vacuum tribology, lubrication choices, life testing, material selection, outgassing and cleanliness requirements.* **Design for Manufacturing, Integration & Test:** Ensure designs are manufacturable, assemblable and alignable. Define the tooling, integration processes and ground support equipment required to build and validate the hardware.* **Supplier Management:** Prepare technical documentation, specifications and RFQs; follow up machining, treatments and manufacturing activities; manage incoming inspections; and incorporate supplier and test feedback into design iterations.* **Environmental Testing:** Support or lead environmental test campaigns, including vibration and thermal-vacuum testing. Contribute to test specifications, predictions, anomaly investigations, non-conformance resolution and qualification documentation.* **Cross-Functional Collaboration:** Work at the interfaces with optical, thermal, electronics and system engineering teams to balance optical stability, alignment, mass, power, pointing, manufacturability and cost constraints.## Preferred Experience* **Education:** Master’s degree or Engineering degree in Mechanical Engineering, Aerospace Engineering or a related discipline. Equivalent practical experience may also be considered.* **Professional Background:** Demonstrable experience taking mechanical hardware from CAD design through fabrication, assembly, integration and testing in a demanding industrial environment.* **Space Experience:** Previous experience with **space qualified hardware is essential**. You understand the constraints associated with vacuum, thermal cycling, launch loads, material selection, contamination control, outgassing and cleanliness requirements.* **Technical Expertise:** + Strong proficiency in a professional parametric CAD environment, ideally **SolidWorks**, **CATIA**, **Creo**, **NX** or equivalent. + Excellent command of mechanical drawings, fabrication documentation and **GD&T**. + Experience with opto-mechanical design, optical benches, precision housings, kinematic and isostatic mounting strategies. + Solid knowledge of precision mechanisms, bearings, preload design, actuation, encoders and cable management. + Experience with vacuum-compatible tribology, lubrication selection, materials and process assurance for space applications. + Ability to specify, perform, steer or challenge FEA, including structural, modal, vibration and thermo-elastic analyses. Familiarity with **SimScale**, ANSYS, Nastran or equivalent tools is appreciated. + Practical experience in thermal design and thermal modelling, including heater sizing, thermal interfaces, athermalisation and test correlation. + Understanding of micro-vibration, line-of-sight stability and their impact on precision optical payloads.* **Qualification & Test:** Experience supporting or leading hardware through environmental test campaigns, particularly vibration and thermal-vacuum testing. You are comfortable investigating anomalies and contributing to qualification and justification files.* **Relevant Industry Experience:** Experience in space systems, defence, precision instrumentation, optical payloads, laser communication terminals or other high-reliability mechatronic systems would be highly valued.* **Mindset:** You combine analytical rigour with a hands-on engineering approach. You are comfortable moving between CAD, analysis reviews, supplier discussions and test facilities, and you enjoy solving complex problems at the interface of mechanics, optics and thermal engineering.* **English:** Professional working proficiency in English, with the ability to write technical documentation and communicate effectively with international suppliers, partners and engineering teams.## Additional Information* Contract Type: **Full-Time*** Start Date: **02 December 2026*** Location: **Paris*** Education Level: **Master's Degree*** Experience: **> 5 years*** **Occasional remote authorized*** Salary: **between 40000€ and 60000€ / year**