Dragons on Mars?

Reuters reports that SpaceX apparently plans to send an unmanned Dragon capsule to land on the Martian surface as soon as 2018.

SpaceX MarsWe’ve landed numerous craft on Mars, and this wouldn’t have capabilities that have made robotic explorers so useful.  However, it would be the first designed to bring humans to Mars, quite a milestone.  While the company has indicated that it doesn’t intend to provide details on the program until September, there is some very interesting potential .

Besides demonstrating the descent and landing technology, the mission could add greatly to our knowledge of radiation exposure and the long term performance of life support systems without a team of highly skilled (and motivated!) mechanics in the loop.  I wonder if the mission could include a simulated crew, consuming oxygen, expelling CO2 and other waste.  Of course the Dragon craft wouldn’t be the only habitable volume for the six month trip in a manned mission, but any opportunity to test systems under challenging, real-world conditions would be welcome.