I understand the various issues related to NASA working through its process of getting out of the launch business while staying in the space exploration business. That is what it needs to do for the U.S. to stay competitive in space with the likes of China, which has a government that can spend money as a few leaders at its top see fit. But, SpaceX has not yet produced what launch vehicles NASA needs, although it seems very likely to do so. At least the SLS has flown a mission that could have put astronauts on the Moon's surface, except that there was no crew aboard, and no lander or gateway satellite there, now. NASA has not developed those, yet, and is hoping that SpaceX will do so in a timely way, but also is hedging its bet with a second contract with Blue Origin. It is a transition process that necessarily has some built in redundancies to avoid failure or unacceptable delay. But, it has to eventually settle down to the companies that can build and launch in quantity and frequency will dominate. Even China is planning to emulate the SpaceX approach to reusable massive launch vehicles. So, I don't think the SLS will last long enough to be the U.S. vehicle to take humans to Mars.