This is encouraging. I've wondered for several years why Mars when you've got places like Venus as potentially more interesting locations. Doing long term atmospheric existence there could teach us a lot about what we don't know about space travel and our ability to push ourselves. If I didn't have two bad discs and was 3 decades younger; I'd be asking where to sign up.

Edit: Reading further, "while the crewed version would be nearly 130 meters long, or twice the size of a Boeing 747.". NASA needs to get much bolder in their thinking. Two people isn't enough. You need at least the size of a submarine crew to make it work and that means an airship 5000 meters long.

Edit 2: "At this point, things get crazy.". Well, it wouldn't be worth it otherwise.