>>> Getting to Mars isn't actually that difficult, we already have a lot of the technical details worked out <<<
What I'm worried about aren't the mechanics of going there. It is the radiation. The Constellation program apparently planned to use high-density polyethylene to act as a shield in the case of a solar flare or any anomalous activity, but the trip would still expose any human being to large doses of radiation and the best methods for shielding are too heavy and hence cost too much right now.
Even if we set up a colony on mars that problem will be ever-present for anyone living there and constructing any long term colony would probably require large amounts of regolith, or maybe a tank of water repurposed as a shield (which might cause processing issues)
Hopefully solving for cost should make a lot of schemes possible, but I'm not so sure about that because there is an implicit requirement of other infrastructure that needs to be solved which no one seems to be tackling. (I might be wrong over here)
Radiation is by far the biggest concern. To some degree there's a bit of a guinea pig aspect for any early Mars astronauts. We do have the ability to at least ensure that the astronauts will survive the trip there and back. The best way to do that is with a combination of shielding around the outer hull as well as a "storm shelter" in the interior of the spacecraft surrounded by lots of water (such as the crew's water and food supply as well as their waste) for sitting out solar flare events. We can monitor solar flares quite well these days so we can keep overall radiation doses in check.
Beyond that we could look at other technologies such as artificial magnetospheres. That sort of thing would probably come into use by the time there are dedicated flights between Earth orbit and Mars orbit.
That makes sense. I'm sure that plenty of people (including me) would still sign up independent of such concerns.
Re: artificial magnetospheres; Wouldn't there be side effects for humans to live within a powerful magnetic field? For starters blood is ferromagnetic... I'm guessing shielding with either something diamagnetic or something like mu-metal is an assumption, but either scenario would be difficult to implement if I'm picturing it right.
What do you think needs to exist to make it viable? Because there is this entire supply chain involved over here which people seem to assume will spring up for such a program. I think that for something so audacious it's a limiting reagent which needs to be taken into account and, hopefully, solved for.
I've read your comments and I hope you don't mind, but I have a silly question for you, do you think it's possible to make a launch system by pumping something cryogenic through a diamagnetic material and using a linear accelerator to accelerate a pellet(large or small) to escape velocity? Such a system would be extremely expensive to set up, but it would be very reusable and it should pay itself back...
The biggest requirement is power, though it's within the capabilities of a large sized solar array. In terms of exposure to the crew, the actual magnetic field experienced within the cabin would probably not be that high (since the magnet itself would likely be on an external boom).
As far as bulk material launch, I don't think there's a ton of value in launching unprocessed raw materials into orbit. There's only a narrow time window where that's actually useful, because once you have built up even a moderate off-Earth industrial base then it becomes easy to produce things like bulk metals and whatnot. The biggest need will always be in complete, manufactured items, and I suspect more or less conventional launch vehicles will probably be the way that happens well into the era where off-Earth colonization is underway.
There have been a lot of studies on this in the international space station and there is essentially a good enough answer for this which involves exercise and physiotherapy once the person is back on Earth.
What I'm worried about aren't the mechanics of going there. It is the radiation. The Constellation program apparently planned to use high-density polyethylene to act as a shield in the case of a solar flare or any anomalous activity, but the trip would still expose any human being to large doses of radiation and the best methods for shielding are too heavy and hence cost too much right now.
Even if we set up a colony on mars that problem will be ever-present for anyone living there and constructing any long term colony would probably require large amounts of regolith, or maybe a tank of water repurposed as a shield (which might cause processing issues)
Hopefully solving for cost should make a lot of schemes possible, but I'm not so sure about that because there is an implicit requirement of other infrastructure that needs to be solved which no one seems to be tackling. (I might be wrong over here)