Mechanical Engineer, Space and Defence FSO Systems

eXalt; Paris (TX); Hybrid; USD 90,000 - 130,000; Full time

Job summary

eXalt is seeking a Mechanical Engineer for Space and Defence FSO Systems to design high‑precision opto‑mechanical hardware for space and defence environments. You will own subsystems from concept through testing, interfacing with optics, electronics and thermal teams to ensure alignment and reliability.

You will apply CAD/FEA tools to develop mechanical hardware, mounts, and thermal solutions, while supporting qualification campaigns, including vibration and vacuum tests, in a demanding

Qualifications

• Experience taking mechanical hardware from CAD design through fabrication, assembly and testing.
• Space-qualified hardware experience with vacuum, thermal cycling and launch loads.
• Proficiency in CAD tools (SolidWorks, CATIA, Creo, NX) and GD&T.
• Ability to specify, perform or challenge structural and thermo-elastic analyses (FEA).
• Collaborative mindset across optics, thermal, electronics and system engineering.

Responsibilities

• Design precision mechanisms including motion stages, bearings and encoders.
• Develop opto-mechanical structures, benches and mounts from concept to detailed drawings.
• Define thermal architecture, heat paths and athermalisation strategies.
• Lead or support structural and thermo-elastic analyses and test correlations.
• Manage tolerance chains affecting optical alignment and stability.
• Support space mechanism qualification, life testing and testing campaigns.
• Collaborate with cross-functional teams to balance performance, mass and cost.
• Ensure manufacturability, assembly, and alignment processes are defined.

Skills

SolidWorks

CATIA

Creo

NX

FEA

GD&T

Vacuum tribology

Thermal modelling

Thermal analysis

Vibration analysis

Education

Master’s degree in Mechanical/Aerospace Engineering

Engineering degree in Mechanical/Aerospace Engineering

Tools

SimScale

ANSYS

Nastran

CAD tools

Job description

Our 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.

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.