The story
From the cables being wrapped around the spacecraft and unreeling in the manner of a double yo-yo.
Etymology from Wiktionary, CC BY-SA 4.0.
yo-yo despin
Today it means: A method of reducing the rotation rate of a rapidly-spinning spacecraft by unreeling a pair of weights from the spinning spacecraft, greatly increasing the spacecraft's moment of inertia and transferring most of the spacecraft's angular momentum to the weights. Full definition →