Henry,
One other point (emphasis added to your original quote):
On Thu, Dec 24, 2015 at 12:34 PM, Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
The one big win is if you eventually want to refuel somewhere off Earth, in
which case it's a lot easier to make methane than anything resembling
kerosene. (Making hydrogen is easier yet -- indeed, making methane may
involve that as an intermediate step -- but it's much harder to store,
which is important since fuel-making is likely to be slow and you'll have
to accumulate fuel for a while. *It's especially hard to store if you're
in an environment, like say the surface of Mars, where there's enough
atmosphere to ruin the effectiveness of MLI.*)