>>10855920Cont->
The 2.0 update would probably have a launch escape system for the crew, and possibly a means of on-orbit abort in the event of TPS damage as well. Payload weight might take a bit, but maybe they'd go with a shorter but wider payload bay designed around launching space station modules into orbit rather than recovering KH-9s. The launch escape capsule would also likely eat into crew living space, but emphasize the design around short transits to and from space stations, rather than around long+endurance solo flights, with long solo science missions carrying a new larger spacelab 2.0/habitation module in the payload bay. Otherwise, keep the SSMEs and OMS from the old shuttle, and keep the launch configuration, with either revised SRBs or kerolox-based boosters. For true 90s /comfy/, maybe NASA could have bought Energia strap-ons from the Ukraine.
The 3rd gen would then probably be the 2nd gen with updated materials/TPS for a lighter bird, with the possibility for a dramatically increased fuel capacity and on-station endurance to allow it to fly translunar trajectories. The launch stack would be an update of the 2.0 stack, but with liquid fuel flyback boosters utilizing SpaceX technology. In addition, it would fly with two external tanks, a smaller one for ISS missions, and a larger extended one for translunar flights. The main publicity stunt would be a moon return flight in time for the 50th anniversary of Apollo 11, with the Shuttle 3.0 (Challenger II, maybe?) flying a lunar orbit insertion trajectory carrying a re-useable lander the size of an ISS docking node in the payload bay, which it then recovers and returns to earth with.
