AEOLDOS – Areodynamic End Of Life DeOrbit System

1. AEOLDOS – Areodynamic End Of Life DeOrbit System Malcolm McRobb Clyde Space Ltd.

2. Do we have a problem? • Access to LEO vital for many services: • Crop monitoring • Navigation • Observation • Disaster Response • Etc… • 1978 – Donald J. Kessler proposes a scenario whereby the density of debris in LEO reaches a point such hat collisions between objects cause a cascading effect. • Approx’ 13,000 objects bigger than a softball; 100,000 pieces bigger than a penny; tens of millions smaller still…. • Hurtling around Earth at up to 18,000 mph. Enter, the CubeSat era: In fact, it is thought that CubeSats account for <1% of orbital debris…

3. Who is responsible for the clear up? WARNING, FUZZY GREY AREA!!! ….but in short, all parties launching spacecraft into LEO should have the moral obligation to ensure that they responsibly, and safely dispose of their craft at the end of its operational lifespan. 25 years is often thrown about as figure, but in reality this is a long time for something to cause a collision…….. • ASI (AgenziaSpazialeItaliana) • CNES (Centre National d'EtudesSpatiales) • CNSA (China National Space Administration) • CSA (Canadian Space Agency) • DLR (German Aerospace Center) • ESA (European Space Agency) • ISRO (Indian Space Research Organisation) • JAXA (Japan Aerospace Exploration Agency) • NASA (National Aeronautics and Space Administration) • ROSCOSMOS (Russian Federal Space Agency) • SSAU (State Space Agency of Ukraine) • UK Space Agency { Inter-Agency Space Debris Coordination Committee (IADC)

4. What are the solutions? Capture vs. Mitigation

5. AEOLDOSAERODYNAMIC END OF LIFE DEORBIT SYSTEM • Passively deployed drag sail • Residual atmospheric particles generate drag forces to reduce host spacecraft velocity. • Double the projected area, halve the time to deorbit. • Compatible to most commercially available CubeSat structures. • Modular; can be either end stack or mid-stack mounted. • Autonomous deployment achievable. • 0.4U – up to 3m2 radially symmetrical sail. • Integrated button cell for deployment activation (no power requirement from host). • Low-cost; in-keeping with the CubeSat ethos. { 0.4U

6. Stored Strain – simple and elegant • Spooled tape-springs are a popular deployment mechanism. • Uni-stable structure due to its C-shaped cross section. • Stores strain energy when wound into a spool. • Only requires electrical energy to initiate release. • Multiple booms can be wrapped around a single spool. • Low-cost prototyping using COTS. Other devices using tape-springs often deploy their booms tangentially…this can lead to a number of problems.

7. Radial Vs. Tangential Deployment Square Hub Petal Hub

8. Radial Vs. Tangential Deployment Square Hub Petal Hub Petal Hub

9. Sail Casting Doors and the Innards Sail casting doors in stowed position Once the spool is released, the booms extend and the doors are cast outwards Sail stowage area Petal Hub ensures safe and robust deployment Cage bearings force the booms to deploy radially

10. Symmetrically Folded Sail Fitted cartridge Optimised folded sail Empty sail cartridge

11. Symmetrically Folded Sail Real-time footage High-speed camera footage

12. 3D AEOLDOS – New Opportunities? Novel Bevel Crux Drive (BCD) that enables the symmetrical deployment of a 3D sail. Utilises the already demonstrated tape-spring approach in combination with radially spaced bevel gears that communicate generated torques evenly throughout the assembly. Research focussing on using the BCD to effectively raise and lower the orbits of host spacecraft.

13. Thank you for listening… please feel free to ask me questions at the end of the session… ….or contact me at Malcolm.McRobb@clyde-space.com