Hmmm... I would wonder why someone would postulate that the speed of light in a parallel dimension would be different than it is here? As far as I know either E=mc^2 or it does not.
The only way that what this article might be suggesting may have some validity is that in this parallel dimension the distance to Mars is less than it is in this dimension (and who is to say?? maybe over there it is closer...) and with only a "3-hour tour" (hmmm...set to music would remind me of a skipper, a millionaire and his wife, and a dude named Gilligan...) that distance would have to be pretty darn close. I wonder, does that article talk at all about these parallel dimensions getting off track at all? That could be seriously dangerous.