A yo-yo de-spin mechanism is a device used to reduce the spin of satellites, typically soon after launch.
[3] Yo-yo de-spin systems are commonly used on sub-orbital sounding rocket flights, as the vehicles are spin stabilized through ascent and have minimal flight time for roll cancellation using the payload's attitude control system.
[4] As an example of yo-yo de-spin, on the Dawn spacecraft, roughly 3 kilograms (6.6 lb) of weights, and 12-metre (39 ft) cables, reduced the initial spin rate of the 1,420-kilogram (3,130 lb) spacecraft from 46 RPM to 3 RPM in the opposite direction.
Yo-yo de-spin was invented, built, and tested at Caltech's Jet Propulsion Laboratory.
In March 2009, a leftover yo-weight caused a scare when it came too close to the International Space Station.