From what I read, they were never even sure of what the centripetal acceleration (G-force) actually was, because of the uncertainty of the measurements.  Either way, I suppose you could call this research, but I have always categorized this as a proof of concept of a potential research method.<p>It should also be noted that NASA has had trouble with tethers in the past, due to vibrations along the wire(s) and orbital mechanics related issues.