What is "astrojax"

Astrojax is a trademark for a toy consisting of three balls on a string. One ball is fixed at each end of the string, and the center ball is free to slide along the string between the two end balls. Inside each ball is a metal weight. The metal weight lowers the moment of inertia of the center ball so it can rotate rapidly in response to torques applied by the string. This prevents the string from snagging or tangling around the center ball.

Roughly, Astrojax play is a cross between juggling, yo-yo, and lasso. A wide variety of tricks and maneuvers can be performed with it. The basic orbits are vertical orbits, horizontal orbits and a figure-eight (butterfly) pattern.

Astrojax was invented by Cornell University physics graduate student Larry Shaw in 1986. It first appeared on the market in 1994, when it was sold through The Nature Company, under the name of "Orbit Balls." Over the next several years it won a number of toy awards. From 2000 to 2015, Astrojax was licensed by Active People, a Swiss company specializing in yo-yos, juggling toys, kites and open-ended toys such as Bilibo. In 2003 corporate chains such as Target, Walmart, KB Toys, and Toys-R-Us started to carry the product.

Several different types of Astrojax have been sold:

• The Plus is made of a soft foam and, because of the softness of the balls, is the best version for beginners. It is good for rebound tricks but not particularly showy.
• The V-max is made from a durable polycarbonate. Because of the reduced friction, the V-max is good for faster moves. The V-max is available in a variety of colours, including half-chromed collectors' editions Black Jack, Amber, Lagoon, Snow White, Pachuli and Hyper Frog.
• The Saturn is made from high-quality plastic and has LEDs inside each ball. The LEDs can be set to be constantly on or a strobing, "disco" mode. The standard Saturn has balls with red, yellow and green LEDs. There is also a version with super-bright blue LEDs called the Blue Diamond.
• The liquid-filled Aqua has a soft bladder of phthalate-free PVC on a hard plastic "vortex." The fluid flows within the bladder dynamically lower the moment of inertia of the balls.
• The MX is a modular version of Astrojax. The modular components are a pressed-metal central weight, two-part vortex, outer mantel (of either foam or thermoplastic resin), string buds, and string. All the modular components, except the central weight, come in at least four colors, thereby allowing a large number of custom color combinations to be assembled.

Astrojax has won a number of toy awards, has been taken into outer space by NASA for their "Toys in Space" program, and there are three Astrojax categories in the Guinness Book of World Records database.