<font color="yellow">Shannon Lucid walked off the Shuttle after 6 months on Mir.</font><br /><br />edit: *She* walked off, yes, but could she walk for potentially a kilometre in a 50 kilogram, stiff EVA suit under 0.6g's of gravity? Possibly involving a climb? Would she have any endurance to do any actual science after such a walk and climb? Would she require a fortnight of gravity conditioning on the surface, and possibly medical aid that she could not provide himself after the 8+g deceleration through the thin mars atmosphere with a heavily atrophied body?<br /><br />Big questions. Not ones I'd spend several hundred billion on answering with a mars surface mission. And you won't get a mission at all if it's for telepresence from orbit. I mean, to me it makes sense, but the public wont support it politically.<br /><br />If we ever want to go to mars we need to answer the partial gravity bone question, preferably soon. There needs to be flags, there needs to be footprints, and there needs to be cameras. Can we stay two years on mars, one year in microgravity, and still survive a 10g+ earth reentry? Why isnt someone putting chimps, lemers and rats in orbital centrifuges to find this &%$#@! out?<br /><br /><font color="yellow">You could use a theoretical EDS as a fuel depot in LLO</font><br /><br />Yes, you could. NASA however would likely come to the genius idea to go minimal development (no kilowatts of power or active refrigeration, and hydrogen) and retrofit an actual EDS, with a cargo lander payload ontop of it to again shave costs. Now you've got a too small fuel depot with excessive boiloff issues that will prevent you from storing useful fuel for useful amounts of time, and will likely break down after a few months.