Columbia93

Since, at least initially, SLS is using 5 Segment SRBs, that are not reuseable, which are very similar to the 4 segment STS boosters which were designed to be reusable, what differences in construction are there? Weight savings? And are there any major improvements?

For the habitat on the surface, are inflatable modules along the lines of those being designed and built by Bigelow Aerospace being considered ?

A followup on the "Why skip the Moon" question. Is the Altair Lander still a viable lander for Lunar missions or was that scrapped completely ?

I followed the Morpheus Lander project, even wrote an article on it, one of the things they were testing was the use of LOX / Methane as a propellant. And I know the whole is there Methane on Mars controversy still rolls on, but is Methane being considered for a fuel to be harvested on Mars for ascent vehicles, manned or unmanned?