What Happens When You Throw a Paper Plane From Space? These Physicists Found Out

Key Points:

• Researchers at the University of Tokyo simulated the descent of an origami paper airplane released from the International Space Station (ISS) to study its behavior during atmospheric reentry.
• The paper plane, weighing just four grams and made of cellulose and kaolinite, remains stable for several days as it spirals down from 400 km altitude, but begins tumbling and burning at around 120 km due to increased atmospheric drag and heat.
• Wind tunnel tests at Mach 7 speeds confirmed the plane's nose would char and deform, demonstrating that such lightweight, plant-based materials would combust upon reentry, effectively making it a one-way trip.
• Beyond curiosity, the experiment suggests potential applications in sustainable space debris disposal and as a sensitive passive probe for measuring upper atmospheric density due to the paper plane’s high responsiveness to aerodynamic drag.
• The study highlights the importance of material choice for spacecraft not only during orbit but also during reentry, contributing to ongoing discussions about space sustainability and atmospheric research.