| I agree with you that the no-gravity part is likely doable with an acceptable risk. What I haven't seen are actual solutions for how to deal with the radiation. Yes, there is ongoing research from NASA, ESA, JAXA and others, and lots of interesting proposals like hydrogenated boron nanotubes, electromagnetic force fields, lithium shields etc. But no solutions even close to implementation. Here's from an ESA blog post on the topic earlier this year: > As it stands today, we can’t go to Mars due to radiation. It would be impossible to meet acceptable dose limits. http://esa.int/Science_Exploration/Human_and_Robotic_Explora... Are we going to send astronauts who have accepted they will likely die from the mission? Is getting a person quickly to mars worth such a suicide trip? The final issue I believe will be a hurdle is the psychology. It's one thing sending people to the moon for a few days, or to the ISS for half a yesr where they can look out the window at Earth every day. But I'm not sure the human mind is going to stand up well to the type of extreme isolation a trip to Mars requires. It's certainly never been tested before. |
https://www.nytimes.com/2013/05/31/science/space/data-show-h...
"According to the National Cancer Institute, the lifetime risk of dying from cancer is 21 percent; the two-thirds of a sievert from a round-trip mission to Mars would raise that risk by three percentage points, to 24 percent."
Mars advocates like Zubrin argue the "acceptable dose limits" are exceedingly conservative, and that NASA willingly permitted far more dangerous operations (like the Shuttle) than radiation incurs.
> It's certainly never been tested before.
Sure it has. https://en.wikipedia.org/wiki/MARS-500