 PLOT: The converted probe is the fictional Voyager 6, supposedly  launched in the 20th century. Given that level of technology, the  speed of such a probe couldnt be much more than that of Voyager 1,  the fastest of all the extrasolar probes launched to date, which is  about .46 light hours per year. Given a speed of .5 light hours per  year, Voyager 6 would only have traveled a tenth of a light year by  the middle of the 23rd century. So where did it meet this alien  probe and get into Klingon space? Chances are that some scientific  expedition would have tracked it down and recovered it for a museum.