Posted on 03/18/2018 1:37:30 PM PDT by SunkenCiv
Not death, but I'd guess it will make it necessary to have some kind of longterm physical therapy if someone returns to the Earth. This has been speculated for a long while, both among scientists (von Braun's Mars mission plan included an extensible boom arm as counterweight, so the Mars-bound craft could spin for simulated gravity) and sci-fi writers at times (Asimov here and there). Mars has about 1/8th the mass of the Earth but a smaller radius, and distance is more significant, so the multiplier for Mars is .38 (your weight times .38), the same as it would be on Mercury's..
I'm also not sure humans can survive for years in underground boxes. I don't think our physiology is designed to live that way. I think we need sunlight and fresh air.
Elon Musk knows his Dad better than we do...
I just gave the transit example to show people have been thinking about it since before humans entered space.
Humans have spent over a year in the microgravity environment of Earth orbit and returned to Earth. The adverse effects have been shortlived. The humans heading to Mars will need to maintain a fitness regimen en route, and provided they manage to establish some sort of permanent dwellings on the surface (that's a big if) the recovery time from microgravity will be even shorter there.
There won't be any lack of exercise, because they'll be spending the remainder of their lives in an agrarian environment, whatever the handwaving by Musk may be.
Jumping on the Earth vs. Jumping on the Moon
imgur
Posted on 01/07/2017 8:59:33 PM PST by LibWhacker
http://www.freerepublic.com/focus/chat/3511910/posts
The Falcon 9's rated thrust has gone up, as has the fuel capacity via subcooling, but they've got to launch seven of them (or seven of anything) without modification or launch failure in order to earn man-rating. The FH is already booked for two paying customers, plus a couple more penciled in. It's also supposed to carry the two space tourists around the Moon, which means it's a good thing the outriggers stuck their simultaneous landings -- the core booster did not. That means, these four commercial sat launches have to go perfectly, plus three others, before the FH can carry the tourists. The Block 5 can't do that, and won't be able to in the future.
BFR will be another "believe it when you see it" -- Musk joked about his failure to hit timetable targets, but claimed there'd be a demo of the BFR in 2019. That suggests that the problems they've had with the Raptor have been solved, and I hope that means we'll see a demo of a Raptor-based test bed soon. A Falcon 9-sized Raptor-powered intermediate booster would be a great idea.
And vice versa. Both of them have a similar interest in younger flashy chicks.
It might not turn out to be a problem, but I think they should plan to have a means to get people back if it turns out to be a problem.
Oh, I wholeheartedly agree. Musk comes off as a huckster when he talks about Mars. I'm actually in agreement with something Robert Zubrin says in his critique of Musk's Mars colony plans -- that the ships don't have to come back, the colonists need to be sent with everything they'll need to survive on the surface. I've been a big fan of the reusability of the F9s, but Zubrin is spot on about this. Recycling the Mars transit vessels takes years, the speed of turnaound is meaningless. A bunch of colonists are going to die, and Musk is going to belong in prison as a consequence of it.
I think the colonizing idea is premature. Till we know for sure that people can survive on Mars for years, we should just look at establishing an outpost and work on transit time.
I have been following the Polywell Fusion reactor research for a long time, and a Anuetronic Polywell system married to a VASIMR engine would give us transit times of so many weeks. I think that is the direction this effort needs to be moving, but at this stage, any method of lofting a heavy payload is useful to the eventual goal.
I commend Musk for developing ways to loft heavy payloads more efficiently than past efforts.
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