Science off the Sphere, Episode 14: Yo-Yos in Space!

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