I'm not sure about strength being mostly compressive -- for example, Apollo 9's Saturn V withstood a longitudinal oscillation with an amplitude of 12g[1] and it

I'm not sure about strength being mostly compressive -- for example, Apollo 9's Saturn V withstood a longitudinal oscillation with an amplitude of 12g[1] and it wasn't deemed to be dangerous enough to cause an abort. I'd expect maintaining pressure in the tanks not to be a significant problem, though it would need to be addressed -- pressure needs to be maintained reasonably constant during the whole burn, and it's done by admitting helium from compressed helium tanks. If the fuel/oxidizer tanks don't leak too much, the same mechanism could be used after the rocket has landed. [1] http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080018689.pdf http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/2008001...