Radiation poses major obstacle to future deep-space astronauts bound for Mars

Astronauts on the International Space Station don't have to worry a tremendous amount about radiation because most individual missions last six months to under a year.

More importantly, they share much of the same protection against solar wind (Earth magnetic field) and cosmic rays (half the spatial angle shielded by Earth) as non-astronauts do. It is just the protection from mainly cosmic rays hitting Earth that the atmosphere make that they lack.

Interplanetary travelers will lack that protection fully (between planets) or partially (near or on most planets). But I hear NASAs risk target is conservative, with at most a 5 % increased lifetime lethality. Half of the global population currently risk on average twice that by moving into cities mainly due to increased pollution (whether or not they are aware of the statistics; and the situation is improving).


"Science begets knowledge, opinion ignorance.
"There are already several robotic missions to the Red Planet, and sending humans there is an exciting future prospect."

After this coronavirus episode is over, I do not believe the world will be the same place. So much is changing. TV interviews with guests speaking over a video link from their homes is now commonplace and I believe this is creating a mindset favouring robotic exploration.

I do accept that the time lag makes a major difference and I am not saying that I am a robot fan. Just that I believe there will be a new slant on exploration.

Of course mankind will continue on its fanatical path to contaminate the Universe so I am sure it will get there eventually (just my opinion) never fear! Perhaps a "hands off - do not touch" approach will do some good.

Cat ;)