Episode 14: Yo-Yos in Space

Science off the Sphere

Astronaut and chemist Dr. Don Pettit does physics demos that are out of this world. Currently on board the International Space Station, Dr. Pettit presents fantastic physics that can only be demonstrated in micro-gravity.


Episode 14: Yo-Yos in Space

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Challenge Question: How is Don's "tether assist" like the tether technology used in satellites?

Challenge Answer: Don's yo-yo acts like an end-mass in a momentum exchange tether system. He spins thestring(tether), thus exerting a centripetal force on the yo-yo. Given that a 2-bodysystem will orbit around its center of mass and Don's hand represents a satellite, the yo-yo and his hand will experience constant acceleration. Momentum exchange can occurif an end-mass is released during rotation. A transfer in momentum to the released masscauses the system to change orbital energy, adjusting satellite orbit.

Challenge Winner: Indronil Ghosh of Folsom, CA


More Science off the Sphere

Episode 1: Dancing Droplets

Episode 2: Bistro-nauts

Episode 3: Thin Film Physics

Episode 4: Lenses and Vortices

Episode 5: Fun with Antibubbles

Episode 6: Earth in Infrared

Episode 7: Space Soundwaves

Episode 8: Goo!

Episode 9: Electric Didgeridoo

Episode 10: 1.21 Legowatts

Episode 11: Space Balloonacy

Episode 12: Spring Theory

Episode 13: Astro Puffs

Episode 14: Yo-Yos in Space