Explained, by Jeff Greason (it’s buried in the comments, so I thought I’d post it up front here):
A little disappointed in the debate above.
I’m going to try, one more time, to explain flexible path. It isn’t hard. You just have to read what we said rather than try to do Kremlinology on what you think we must have meant.
I’ll boil it down the same way that I explained it to policy makers.
* We want to go to Mars.
* We can’t reasonably go to Mars without more experience with long-duration missions.
* Long-duration missions can be done to Lagrange points, NEO’s, and Phobos/Deimos and they are all worthwhile missions in their own right.
* We can’t reasonably go to Mars without updating our experience doing manned planetary exploration.
* Manned planetary exploration would be done on the Moon, which is a worthwhile mission in its own right, and could be a source of propellant for exploration.
* The Moon vs. Mars vs. NEO’s is therefore a FALSE CHOICE; the only choice we have is what sequence we do them in.
* Therefore, the only reasonable way to proceed is to accept that we MUST plan to do all of these things and plan accordingly.
* Since the spacecraft, lander, and boosters/EDS’s are the expensive part, constrained budget says develop 1 or at most 2 of them first.
Now, the version of this in the Augustine report was:
* Do the boosters/EDS’s and spacecraft first
* Do buildup flights in LEO, Lagrange, Cislunar, NEO’s
* Do Lunar landings
* Do Mars
(whether Phobos came before or after Lunar landings really wasn’t clear, it depends on how the technologies shake out).
Look at the mission timeline in the report, under flexible path, and you see Lunar landings, NEO visits, and Phobos visits before Mars. Construing that as “abandoning the moon” or “don’t touch” requires one to either refuse to read the report, to assume we only meant part of what we said, or to be dishonest.
Today, as it seems the NASA budget may not support doing 2 elements at once, I would suggest we do one at a time:
* then boosters
* then landers
Because that way we can begin the exploration sequence with spacecraft on existing boosters and build the (relatively modest) upgraded boosters we need for more agressive missions as we go.
Makes sense to me. But the “look but don’t touch” morons will continue to be confused. I’m sure that we’ll be discussing this this evening, on a panel on which Jeff and I will be on, at the conference.