Certainly. First, build the Shuttle-C : although hardly perfect by any mean, it provides a HLV.
And then start building the Mars ship. One external tank, filled to the brim, should be enough to send a decent expedition to Mars.
Maybe an habitat could be added, with an ACC - Aft Cargo Carrier. The neat thing would be that it would be partially radiation-shielded by the enormous tank.
Spacelab modules seems an obvious choice for the habitat.
Main problem are
- the lack of capsules for Earth return, because Apollo was long dead
- the Mars lander which has to be build from scratch.
- the lack of a viable LOX/LH2 engine
a) RL-10 are too small
b) J-2 is long dead
c) SSME was designed to start and work from the ground, not in space
Lot of re-inventing the wheel, but technically doable.
The huge problem is NASA itself. Two abysmal byproducts of its catastrophic 1980's shape
- STS-51L
- The 90-day-study in 1990 (their answer to Bush 41 request for a Mars shot)
1980's NASA was dysfunctional at so many levels, I wouldn't bet my life on them, as an astronaut...
As for the pretext... have the Soviets throw Reagan into panic, succeeding with Mars 4M and 5M.
Or Mars 4MN and 5MN.
IF the Soviets brought back Mars samples in the early 80's, Reagan should blow a fuse enough to forget SDI and return to a more peaceful space race...
[URL unfurl="true"]http://www.astronautix.com/m/mars5m.html[/URL]
[URL unfurl="true"]http://www.astronautix.com/m/mars5nm.html[/URL]
(obviously, considering the catastrophic record of both Soviet Mars probes and N-1 rocket, that would be an enormous stretch...)
