Executive Summary
Astravon partnered with a European aerospace company to deliver a 410 mm λ/20 PV precision flat mirror for a cleanroom optical testing system. The project involved challenges in system definition, gravitational deformation concerns, cost scaling, and quality validation. By focusing on high-precision manufacturing and clearly defining scope, Astravon reduced risk and ensured efficient delivery. The team also provided guidance on cost-performance trade-offs and testing methods. The result was a reliable, high-performance optical solution, reinforcing Astravon’s role as a trusted partner in aerospace optics.
Project Overview
Astravon was engaged by a leading European aerospace and satellite imaging company to deliver a large-aperture, ultra-high precision flat mirror (~410 mm diameter). The mirror would serve as a critical component in a cleanroom-based optical testing system, positioned facing downward and aligned precisely with a device under test (DUT).
The application demanded exceptional surface accuracy (λ/20 PV), mechanical stability, and seamless integration into a custom alignment system
A large flat mirror
Key Challenges
1. System-Level Design Complexity
The customer required support extending beyond optics into mechanical integration, including:
- Multi-point clamping mechanisms
- Motorized tip/tilt alignment systems
However, incomplete system definitions—such as DUT specifications, environmental conditions, and load factors—introduced uncertainty in optimizing the full system design.
2. Optical Performance Uncertainty in Real Conditions
The customer expressed concern about maintaining λ/20 PV surface accuracy when the mirror is mounted horizontally (facing downward).
Key question:
Would gravitational deformation compensation (pre-biasing) be necessary?
To address this concern, Astravon conducted finite element analysis (FEA), which indicated that for a 410 mm aperture, gravitational deformation under downward mounting is less than λ/50 PV, demonstrating that pre-bias compensation is not required.
As an alternative solution for enhanced performance assurance, Astravon also evaluated a three-point rear support configuration combined with pre-compensated polishing. Interferometric measurements confirmed that the system maintains λ/20 PV surface accuracy after installation.
This analysis and validation ensured lab-grade precision could be reliably maintained under real operational conditions.
MFT Testing for the large flat mirror
3. Scaling vs. Cost Trade-offs
The customer explored increasing the mirror aperture from 410 mm to 650 mm, but encountered:
- A 4–5× increase in cost
- Increased manufacturing complexity
- Greater risk in maintaining precision
Balancing performance ambitions with budget constraints became a critical decision point.
4. Quality Verification & Acceptance Risk
The customer needed clarity on:
- Post-delivery optical validation methods
- Appropriate testing protocols and standards
This reflected concerns about:
- Measurement capability
- Acceptance criteria for ultra-precision optics
Astravon’s Approach
1. Clear Scope Definition to Reduce Risk
Astravon established a well-defined responsibility boundary:
- Astravon: High-precision optical manufacturing
- Customer: Mechanical mounting and system integration
This approach delivered:
- Reduced engineering ambiguity
- Faster project execution
- Predictable performance outcomes
2. High-Precision Optical Manufacturing
Leveraging Sage-level craftsmanship and process control, Astravon delivered:
- λ/20 surface accuracy
- Controlled fabrication in cleanroom-compatible environments
- High consistency across the full aperture
This ensured the mirror met stringent aerospace optical performance requirements.
A high-precision large flat mirror
3. Transparent Trade-off Guidance
Astravon provided clear, data-driven insights on:
- Aperture scaling impacts (410 mm vs. 650 mm)
- Cost-performance relationships
This empowered the customer to:
- Make informed engineering decisions
- Align system design with budget realities
4. Supporting Quality Assurance Strategy
Astravon provided clear, data-driven insights on:
- Recommended interferometric testing methods
- Acceptance criteria aligned with λ/20 PV specifications
- Best practices for optical validation in cleanroom setups
This reduced uncertainty and strengthened confidence in final system performance.
Results & Impact
- Delivered a high-precision flat mirror meeting λ/20 PV requirements
- Reduced system-level risk through clear responsibility alignment
- Enabled cost-effective decision-making for aperture scaling
- Improved customer confidence in validation and acceptance processes
Conclusion
By combining precision manufacturing expertise with transparent engineering guidance, Astravon—through its Sage brand philosophy—helped the customer navigate complex design uncertainties and achieve a reliable, high-performance optical solution.
This project highlights Astravon’s role not just as a supplier, but as a trusted technical partner in aerospace optical systems.
Partner with Astravon
Astravon aims to be a trusted engineering partner for optical systems that must perform as intended, throughout their operational life.