"tall order" to build it in 150 years. Does this NASA director know what the world was like 150 years ago? Virtually all of the technology and all of the thing we have built today did not exist then, nor did the people to build them.
Step 0 to build something like the Elysium is to build large scale, fully automated factories that can churn out the parts to build such a station. Bonus points if those factories can also build many of the components used to build more factories, because you're going to need a lot of them.
Step 1 is to build a set of superconducting quench guns that you would use to actually put those parts into space.
Step 2 is to build more of these automated factories on the moon, since there's no environmental laws against strip mining, and plenty of real estate. Also no atmosphere to slow down your quench gun launches, and a fraction of the velocity needed.
Step 3 is to assemble all that shit together in space.
Now, building a single monolithic ring that rotates for centrifugal pseudo-gravity - THAT's hard to do and probably a bad idea (since if the ring fails, you lose the whole station). I'd much rather see several thousand smaller "hab modules" that spin opposite one another on big cables. You'd take transit cars or small spacecraft to move between the hubs of different modules (and ride an elevator down the cable to each distinct module)
If a cable snaps, you can send a recovery spacecraft to recovery them individual modules - if they didn't crash into anything, the occupants would probably be uninjured.