Your Lack Of Understanding Is Showing Again
It takes about the same minimum energy to reach Mars as The Moon. It would take more effort to bring the bodies home, but not to send a robotic mission to survey the damage. That is of course assuming appropriate timing. A time sensitive investigation would require more energy, but not by an order of magnitude unless you are assuming something far beyond minimum energy paths. Or are you talking about sending humans without understanding what killed the last crew?
Regards,
Mark