Turns out your 90s era CD player may not be obsolete after all—if you're in space, that is.A few self-dubbed "engineering types" experimented with CD players in zero gravity at the International Space Station, and found patterned differences in the way the devices wobbled around in air. ISS Science Officer Don Pettit demonstrates in the video what happens with various CD players in the "on" and "off" modes.A CD player in the "on" mode with a spinning disc inside presented a fair amount of "gyroscopic stability," quivering quickly back and forth, while a CD player in the off mode "freely tumbles around its center of gravity." The makers of the video went on to tape two CD players together, and then three together, examining what happened when the players were each turned on or off.With three CD players attached and turned on, the structure achieved enough stability to even become useful to the astronauts, who used it as a third "hand" to hold a flashlight when working with a drill in dark corners of the space station.One student asked if playing heavy metal would give the CD players more stability. "I don't think so," the narrator responded dryly, but the jury could still be out.The video is undated, but what appears to be an earlier version served as the final episode of Pettit's series Saturday Morning Science, released in 2003.