I agree with you that there is are a wide variety of ideas about SLS and Orion in NASA, but the official policy (and the basis for this thread) is that SLS will take NASA to Mars.  In  the article you cited, Bolden is saying that he needs commercial crew to be fully funded to enable research on the ISS, which will allow for the use of SLS on trips to Mars. From the article:<p>&gt;<i>Bolden said that without the ISS, he would recommend that SLS and Orion be cancelled.</i><p>SLS and Orion are useless and should be cancelled without respect to what happens with the commercial crew program.  SLS or derivatives thereof will not allow for the expoloration or colonization of Mars, the system is already in a cost&#x2F;scope death spiral, and even if it is completed, it will be too expensive and too unreliable to be used for its intended purpose.<p>If NASA really wanted to go to Mars, they would propose cancelling SLS, and spending the money on Blue Origin, SpaceX, and Orbital Sciences (and possibly Skylon).  BO, SX and OS super-heavy launch systems could be developed for a combined cost lower than SLS&#x27;, they will have lower specific cost to orbit ($&#x2F;kg) and they do not have the problems which NASA has with cost and schedule overruns.  They could even fund two of the super-heavy launch systems, and use the extra money for launches to do induced low-gravity research, and high-efficiency propulsion research (amongst other things).