Keeping space clean: ΦINIX-1 team tests CubeSat drag sail at ESA’s CubeSat Support Facility

Empowering student teams for a more sustainable future in space

Space debris is increasingly posing collision risks to operational missions. ESA Academy's Fly Your Satellite! (FYS) programme is supporting efforts to clean up Earth’s orbit and investing in students who will carry that mission forward. Aligned with ESA’s zero space debris approach, the ΦINIX-1 student team from the National and Kapodistrian University of Athens has taken the bold step of developing and testing a CubeSat drag sail — an innovation aimed at supporting a more sustainable orbital environment.

Drag sail technology: a clean space solution

Drag sails are a cost-effective and reliable method for accelerating the deorbit of small satellites, especially CubeSats, at the end of their mission lifetime. By increasing the satellite’s surface area, a drag sail increases the effect of atmospheric drag in low Earth orbit, ensuring faster re-entry and disintegration in the atmosphere.

The ΦINIX-1 team has engineered a lightweight, compact, and deployable sail, integrated into a CubeSat bus. The sail is a type of passive post-mission disposal technology - a system that allows a spacecraft to move or deorbit without needing commands or propulsion.

From proposal to testing: the ΦINIX-1 journey

The ΦINIX-1 team was selected for the March 2025 test window of ESA Academy’s FYS Test Opportunities programme, following a call for proposals launched in September 2024. The FYS Test Opportunities programme provides university teams and early-career professionals with access to educational test facilities which can provide test environments as used for qualifying professional missions.

After completing the test preparation phase and receiving approval for the test campaign execution plan, students from the ΦINIX-1 team travelled to Belgium.

Vibration and thermal vacuum testing at the CubeSat Support Facility

The primary objective of the two-week test campaign was to qualify the drag sail’s design under representative conditions that simulate the launch and orbital environment by subjecting the system to:

•  Vibration testing: Simulating launch-induced stresses to verify structural integrity and deployment reliability. The team conducted both functional and vibration tests to assess the drag sail system’s performance under launch conditions during the first week.

• Thermal vacuum testing (TVAC): Replicating the extreme thermal cycles and vacuum conditions of low Earth orbit to ensure functionality in space-like conditions. These tests were carried out during the second week, following the so-called “test as you fly” approach.

 

 

 

These tests were not only critical for verifying the drag sail’s design but also served as a hands-on learning experience for the students. The team participated in the full test campaign lifecycle – from pre-test preparations and cleanroom procedures to data analysis and documentation – gaining valuable skills in spacecraft systems engineering, test management, and contamination control.

Test outcomes: learning through challenges

The drag sail’s vibration test was successfully completed, confirming the mechanical robustness of the system under launch-like conditions. However, during the TVAC testing, the system did not perform as expected. While initially a setback, this outcome was ultimately one of the most valuable learning experiences for the team.

In the space sector, testing is not just about success, it's about learning. Failures during environmental qualification provide critical insights into design limitations, material behaviour, and system integration under real space-like conditions. For the ΦINIX-1 team, the TVAC testing led to a deep dive into product assurance. Supported by ESA’s expert staff, operators, and test facility environment, the experience reinforced the reality that failure during testing is where learning happens.

A training ground for future space professionals

The ΦINIX-1 drag sail test campaign is more than a technical milestone. It is also a vivid example of how practical educational programmes help train the next generation of engineers and researchers. Through mentorship, peer learning, and industry engagement, the Fly Your Satellite! programme fosters a growing ecosystem of young professionals ready to lead future missions.

The students from the National and Kapodistrian University of Athens gained hands-on experience in executing high-level testing campaigns, mastering documentation, and adhering to strict laboratory protocols. The team commendably adapted to the off-nominal events and expertly managed all the processes and challenges encountered during the environmental test campaign.

Looking Ahead

With the testing now complete, the ΦINIX-1 team are preparing for the next phase of analysing the data collected during the test campaign. The results will be used to refine the drag sail design, leveraging all the lessons learned during their testing.

ESA Academy is proud to have hosted the ΦINIX-1 team and congratulates them on their achievements. Their work contributes meaningfully to the global effort to keep space clean and accessible for future generations.

About ESA Academy test opportunities

Beyond satellite projects, the FYS Test Opportunities programme extends to a broader audience, such as REXUS teams and participants in the ESA Academy Experiments programme, fostering innovation across multiple disciplines. To learn more, click here.