Not to disturb your 3 way conversation, but I just wanted to add support to the notion that NASA is gradually losing viability as the sole agency for both building and running our nation's space program. Why? Because of the bureaucratic overhead of being a government agency. They aren't nearly as nimble as something like Space-X. NASA made sense in the day when the private sector was nowhere near capable of doing what NASA could do. Today the technologies, materials, and brain trust involved have become far more accessible. While I don't think NASA will disappear completely anytime soon, I do see it shifting out of the building end of the business. Private companies will build the hardware with more control and autonomy over the specifications, while still making exceptions and customization for NASA, the customer.
The old veterans like Buzz Aldrin don't want to hear this. But that's the age old problem of the elderly, who are usually stubborn about not making changes to what they know. What they forget is that NASA commissioned the likes of Lockheed and Grumman to build what they needed. The model isn't terribly different. It's just that the government would be less involved in control over how and what gets built. Actually, I think it makes for a better product because there's some competition at hand.