MM or MC......Voyager Expedition

Watched a very interesting program on PBS the other day about the Voyager Expedition.  A lot of time was devoted to the gold record that accompanied the space craft on its journey.  The Chief Engineer mentioned that a cartridge was included along with the record and with graphic instructions on how to play the recording.  No mention by the engineer if MM or MC cartridge was chosen.  Does anyone have any inside information on what type of cart was included?  Just curious.....Thanks!