I remember when the first ISS expedition crew was launched (may 2000?), I thought from now on, there will always be someone in space at all time.
Then there was Columbia, exactly one year ago.
And the recent Bush's space initiative (not followed or re-assessed during the SOTO) and the most certain thing about Bush's speech is that the Shuttles won't be flying into space after 2010 and that money for the ISS will stop once the station is considered completed at around the same time.
The CEV (now part of something called "Project Constellation) will likely replace the Shuttle, but will that help maintain a permanent presence in space? At around that time, when the CEV will be ready, we'll see that the ISS is still up there and ELVs can launch the CEVs to the ISS for much less money than the STS.
The Shuttles were meant first to be one part of a triptic:a Shuttle, a Station and a Space tug. Then it was only the Shuttle which was meant to carry all kinds of payloads from 28 degrees inclination (KSC) to 98 degrees inclination (SLC-6) but the SLC-6 and the commercial payloads, the military payloads were dropped after Challenger.
Can the CEV grow to such a momentum that it can take astronauts to the Moon or are changes to its configuration too extensive (even if they don't appear that way, today) to make it go all the way ? Or is yet another kind of vehicle needed for Moonlandings anyway?
In the early 90's there was the Early Lunar Access General Dynamics project. What I find very interesting about it is that it needed only two 25 to 27 tonnes capacity to LEO ELVs to take 2 astronauts to the Lunar surface, and back.
It may not be the way it will be achieved, but it's an idea and that's what we need to go out there.
raoul