Introduction
In recent years, the demand for small satellites has surged, driving the need for efficient and cost-effective launch solutions. However, Europe has lagged in developing dedicated small launch vehicles. The ENVOL project, part of the European Commission’s Horizon 2020 Programme, aims to bridge this gap by developing a micro-launcher that offers frequent, flexible, and low-cost access to space for small satellites. This blog explores the innovative manufacturing processes developed within the ENVOL project, focusing on efficiency and automation, and highlights the benefits for the small launcher industry. Jaap Dekker wrote an indept paper about the project. Are you interested in this paper? Please contact Jaap via Linkedin.

Research and development insights
The ENVOL project’s research has focused on overcoming the challenges associated with manufacturing complex structures for small launchers. Key research insights include:
1. Design optimization
The research team developed a parametric Python script to design feasible tow paths for the AFP process, considering the minimum tow steering radius and the need to manage gaps and overlaps. This approach enables Airborne to quickly design and optimize a new tank with a different geometry and requirements, utilizing the full potential of the AFP process.
Furthermore, for the draping process, the team used simulation software to predict the draping behaviour of multi-angled UD stacks. This helped in designing patches that minimize fibre angle deviations and wrinkling, ensuring high structural performance.
2. Material and process validation
Extensive trials were conducted to validate the manufacturing processes. For instance, the AFP process was tested to determine the minimum steering radius for different fibre angles, ensuring the fibres do not buckle or wrinkle. Also, FEA was used to estimate the knock-down factor of manufacturing limitations. This analysis helps in understanding the impact of manufacturing defects on the structural performance of the tank.
3. Integration and assembly
The tank assembly involved cold-bonding the two tank sections together and integrating an aluminium liner as a chemical barrier, also allowing the integration of other internal system. The outer shell, including skirts, was manufactured using ATL and co-bonded to the tank during an autoclave cure-cycle. This results in a structurally integrated tank that can easily be integrated into a launcher structure.

Automated manufacturing processes
The ENVOL project has pioneered two novel manufacturing processes for a structurally integrated second stage H2O2 tank for small launchers. These processes are designed to be highly automated, reducing costs and increasing production rates.
Automated Fibre Placement (AFP)
The AFP process involves laying down continuous fibres with precise control over their placement and orientation. This method is used for the bottom dome and cylindrical section of the tank. AFP allows for local reinforcements, resulting in significant weight savings compared to traditional methods like filament winding. The process is highly flexible and can be adapted to various geometries, making it ideal for complex structures.

Automated Tape Laying (ATL) and Draping
The ATL process is used to create flat stacks of Uni-Directional (UD) material, which are then cut into patches and manually draped onto the mould for the top dome. This method combines the efficiency of ATL with the flexibility of manual draping, resulting in a high-quality product. The use of UD material enhances structural performance while reducing material costs.
Benefits for small launcher industry
The automated manufacturing processes developed in the ENVOL project offer several key benefits for small launcher manufacturers:
Cost efficiency
Automation significantly reduces the need for manual labour, lowering production costs. Also, precise control over fibre placement minimises material waste, further reducing costs.
Scalability
Automated processes enable higher production rates, allowing companies to scale up operations quickly to meet increasing demand. Automation also ensures consistent quality across all manufactured parts, reducing the risk of defects and improving reliability.
Innovation and competitiveness
The flexibility of AFP and ATL processes allows for innovative design solutions that can enhance the performance of small launchers. By adopting cutting-edge manufacturing technologies, startups and scale-ups can differentiate themselves in a competitive market, attracting investment and customers.
Conclusion
The ENVOL project’s focus on efficiency and automation in manufacturing small launcher components represents a significant advancement for the aerospace industry. By leveraging these innovative processes, small launcher manufacturers can achieve cost-effective, scalable, and high-quality production, positioning themselves for success in the rapidly growing market for small satellite launches.
For companies in the small launcher industry, embracing these technologies not only enhances operational efficiency but also drives innovation and competitiveness, paving the way for a new era in space exploration.
Feel free to reach out if you need additional information.
