A few weeks ago, some artwork was put on ebay showing an alternate concept for the Lunar Roving Vehicle. This one was apparently sold as being optionally manned, which would certainly be a useful feature. Especially if it could be teleoperated from Earth after the crew has gone home. Note that one of the illustrations shows the unmanned rover towing a two-wheeled cart loaded with nuclear power generator (an RTG); similar RTGs are shown hanging off the sides of an unmanned LRV, and two RTGs are shown in the distance in the illustration showing unmanned-to-manned conversion. What *may* be intended here is that the unmanned version would drive around under RTG power and charge up batteries; for manned use the RTGs are left in the distance and the things operates purely under battery power. If returned to RTG/unmanned prior to the crew leaving, then the LRV would have virtually unlimited range. With enough time, an LRV could even drive to another landing site and be there in time for a new crew to land and make use of it.