I went to the Royal Institution last night to hear a talk by Dr. Kevin Fong, an anaesthetist who actively studies the health problems associated with spaceflight, and who has just returned from a period spent studying at the Johnson Space Centre.
The main point he made was that the best strategy for a Mars mission was a thousand-day mission, entailing a nine-month outward flight. He explained that after that length of time in microgravity conditions, the crew of such a mission would be in no fit state to carry out any science, let alone to get out of their landing capsule and set up a base. He mentioned such problems as motion sickness, skeletal mineral loss (2% per month, apparently) and muscular degradation.
While describing these issues, Dr. Fong also described the differences between going for a ride on NASA's "Vomit Comet" and going for a ride on the Russian equivalent. NASA require you to turn up a week before, and go through all sorts of medical checks and briefings over the course of four days before you actually go for a one-and-a-half hour flight. In Russia, they sling you in the back of the plane, say something along the lines of, "Here's a parachute, if something goes wrong, open the door and jump out and try not to land in water," and then off you go.
He also described the current design for a manned Mars spacecraft. Essentially, it's a fold out scaffold 125 m in length, with a TransHab-type module at one end, a SP-100 class nuclear reactor at the other, and engines and antennae in the middle. He also mentioned that liquid hydrogen is being considered for use as the habitable module's radiation shield, but I remain sceptical.
I felt that the talk didn't really go into enough techical detail for me. Talking to some scientists beforehand, I discovered that I'd missed a very interesting lecture at the Royal Society last Thursday. Oh well.
Dr. Fong made several references to the Space Shuttle being withdrawn from service in 2010, and after the talk I asked him what sort of things were being considered as a replacement. He mentioned the Crew Exploration Vehicle (which I'd already heard about) and also a cargo launcher called Magnum (which I hadn't). Cursory Googling brings up the fact that it's being developed by MSFC, and not much other useful stuff. I'll investigate.