LEOniDAS drag sail experiment on the 2021 ESA Fly Your Thesis! parabolic flight campaign

Space engineering students and academics from Cranfield University have developed two space debris mitigation drag sail concepts and three sails are currently in orbit. The sails enable a reduced time to atmospheric re-entry by increasing the natural aerodynamic drag forces acting on the host satellite. Intended to be used on small, low Earth orbit satellites, these sails provide a low-cost solution to achieving compliance with the IADC target of removal from orbit within 25 years of end-of-mission. The LEOniDAS team, comprising one PhD and three MSc students, submitted a proposal to the ESA Fly Your Thesis! parabolic flight campaign to perform microgravity deployment testing on a more scalable and adaptable hybrid design. The project aimed to qualify the new design, provide a better understanding of deployment behaviour in microgravity and allow for a deeper understanding of the effect of deployment on the host satellite. Participation in the programme provided significant educational benefits to the students involved, resulting in three Masters theses and a major input to a PhD thesis, as well as publications and outreach activities. The experiment was presented by the students at the ESA Academy Gravity-Related Training week in January 2021. There followed extensive design, prototyping and assembly work, with regular review and input from ESA and Novespace, culminating in the two-week parabolic flight campaign in October 2021. The planned deployment experiments were successfully completed across all three flights, with the experimenters accumulating a total of more than 30 minutes of microgravity. Data on dynamics of the sail deployments was recorded via high-speed video cameras, accelerometers and torque sensors. This paper will highlight the key scientific and educational achievements of the project, and summarise the lessons learned for the benefit of future participants in this exceptional student opportunity.