5 ms·

Not everyone is ready to admit it yet, but IMO there is no long term future for us in space without something like artificial gravity. I remember back in the 1

Not everyone is ready to admit it yet, but IMO there is no long term future for us in space without something like artificial gravity. I remember back in the 1970s one of the Skylab astronauts came to my college to give a talk. I had read about some problems, so I asked him about the effects of prolonged weightlessness. He was very dismissive, he vehemently denied that there could be any problems at all. As they say, denial isn't just a river in Egypt. And the denial has been going on for many many decades.

trentmb 10y ago
> He was very dismissive, he vehemently denied that there could be any problems at all. We exist as we do because of the pressures our environment exhibits on us (e.g. gravity)- outside of hubris I can't imagine why folks would think weightlessness would have zero impact.
- hoorayimhelping 10y ago
  >We exist as we do because of the pressures our environment exhibits on us (e.g. gravity)- outside of hubris I can't imagine why folks would think weightlessness would have zero impact. Skylab 2, 3 and 4 specifically tried to study the effects of space habitation on the human body. I seem to remember reading that the later Skylab crews were considered to be in better health when they came back than when they left. Even though it was early, it could explain the dismissiveness. The data at the time might have made it seem that we'd figured it out already.
gizmo686 10y ago
I am not aware of research on how much gravity is needed to maintain a healthy environment. For example, it is possible that an body as light as Pluto (with only .06 Gs) would offset the majority of the effects of low gravity. If this is the case, then permantant bases on Moons/Planets would face little issues from micro-gravity concerns. If humans require closer to 1G to remain healthy, then these bases become more difficult. We have already demonstrated that humans can stay in space for over a year while remaining relativly healthy. Further, we can achieve artificial "gravity" with centrifugal force if we needed to. Additionally, we could also attempt to solve the problem through medical science, and treat the effects of micro-gravity instead of outright preventing it.
- stuff4ben 10y ago
  That's a great point. Makes me wonder why we're not getting that moon base setup. Seems like a natural first step prior to colonizing Mars. Learn how to survive on the Moon, take that knowledge and apply to Mars.
jerf 10y ago
Artificial gravity is easy. You "just" spin things. The tricky bit is being able to launch enough mass to build something safe and comfortable to spin; there's a limit to how small you can make your spinning habitat before the difference between "centrifugal force" and gravity is too pronounced for our long term comfort. That's part of why making it cheaper to launch per unit mass is so important. If we could put ten times the mass in space for the same price, the ISS would probably look quite different. I'm of the same opinion as you in general; what spending years in zero-g has proved is that it's not long-term viable. There's too many ways in which it is not viable to expect us to be able to fix all of them, when indeed it's not clear we can fix any of them with drugs or anything short of massive genetic engineering. We don't know how much gravity is necessary, though I'm inclined to guess closer to .5G than .05G. Once you get enough mass in space, though, that's not really that difficult.
- jfoutz 10y ago
  Two skylabs and a really long rope seems pretty achievable. The full wheel from 60's sci fi looks very cool, but two weights on opposite sides of a string seems so much simpler.
  - lttlrck 10y ago
    This idea is used in Seveneves https://en.m.wikipedia.org/wiki/Seveneves https://en.m.wikipedia.org/wiki/Seveneves
- hoorayimhelping 10y ago
  >The tricky bit is being able to launch enough mass to build something safe and comfortable to spin; Is it? I might have a completely busted mental model, but I thought you only need a module-sized mass on one end of a rod the length of things we've already assembled in space (e.g. an ISS truss) and a motor to spin it.
  - jerf 10y ago
    It gets complicated, and the mass budget starts going up fast, if you want other things to be able to dock to it. Two space stations on the opposite side of a long rope (per the other reply) is also not a very compelling story to tell to Congress when you have to admit that astronauts won't be able to travel between those two space stations to speak of, unless, again, you really up the mass budget. We're space-poor. It's just too darned expensive. Even relatively simple designs are out of our reach right now, if you have to manifest them in real designs with real safety margins and real practical applications, such as being dockable.
vixen99 10y ago
'no long term future for us in space without something like artificial gravity.' and without an answer to the radiation problem. http://www.wired.com/2014/04/radiation-risk-iss-mars/ http://www.wired.com/2014/04/radiation-risk-iss-mars/
mkstowegnv 10y ago
Except for Venus with .9 Earth gravity and where colonies floating above the clouds have many advantages over, and may be no more difficult to create than, colonization schemes for Mars or anywhere else in space/away from Earth. https://en.wikipedia.org/wiki/Colonization_of_Venus#Advantages https://en.wikipedia.org/wiki/Colonization_of_Venus#Advantag...

trentmb 10y ago

> He was very dismissive, he vehemently denied that there could be any problems at all. We exist as we do because of the pressures our environment exhibits on us (e.g. gravity)- outside of hubris I can't imagine why folks would think weightlessness would have zero impact.

hoorayimhelping 10y ago
>We exist as we do because of the pressures our environment exhibits on us (e.g. gravity)- outside of hubris I can't imagine why folks would think weightlessness would have zero impact. Skylab 2, 3 and 4 specifically tried to study the effects of space habitation on the human body. I seem to remember reading that the later Skylab crews were considered to be in better health when they came back than when they left. Even though it was early, it could explain the dismissiveness. The data at the time might have made it seem that we'd figured it out already.

gizmo686 10y ago

I am not aware of research on how much gravity is needed to maintain a healthy environment. For example, it is possible that an body as light as Pluto (with only .06 Gs) would offset the majority of the effects of low gravity. If this is the case, then permantant bases on Moons/Planets would face little issues from micro-gravity concerns. If humans require closer to 1G to remain healthy, then these bases become more difficult. We have already demonstrated that humans can stay in space for over a year while remaining relativly healthy. Further, we can achieve artificial "gravity" with centrifugal force if we needed to. Additionally, we could also attempt to solve the problem through medical science, and treat the effects of micro-gravity instead of outright preventing it.

stuff4ben 10y ago
That's a great point. Makes me wonder why we're not getting that moon base setup. Seems like a natural first step prior to colonizing Mars. Learn how to survive on the Moon, take that knowledge and apply to Mars.

jerf 10y ago

Artificial gravity is easy. You "just" spin things. The tricky bit is being able to launch enough mass to build something safe and comfortable to spin; there's a limit to how small you can make your spinning habitat before the difference between "centrifugal force" and gravity is too pronounced for our long term comfort. That's part of why making it cheaper to launch per unit mass is so important. If we could put ten times the mass in space for the same price, the ISS would probably look quite different. I'm of the same opinion as you in general; what spending years in zero-g has proved is that it's not long-term viable. There's too many ways in which it is not viable to expect us to be able to fix all of them, when indeed it's not clear we can fix any of them with drugs or anything short of massive genetic engineering. We don't know how much gravity is necessary, though I'm inclined to guess closer to .5G than .05G. Once you get enough mass in space, though, that's not really that difficult.

jfoutz 10y ago
Two skylabs and a really long rope seems pretty achievable. The full wheel from 60's sci fi looks very cool, but two weights on opposite sides of a string seems so much simpler.
- lttlrck 10y ago
  This idea is used in Seveneves https://en.m.wikipedia.org/wiki/Seveneves https://en.m.wikipedia.org/wiki/Seveneves
hoorayimhelping 10y ago
>The tricky bit is being able to launch enough mass to build something safe and comfortable to spin; Is it? I might have a completely busted mental model, but I thought you only need a module-sized mass on one end of a rod the length of things we've already assembled in space (e.g. an ISS truss) and a motor to spin it.
- jerf 10y ago
  It gets complicated, and the mass budget starts going up fast, if you want other things to be able to dock to it. Two space stations on the opposite side of a long rope (per the other reply) is also not a very compelling story to tell to Congress when you have to admit that astronauts won't be able to travel between those two space stations to speak of, unless, again, you really up the mass budget. We're space-poor. It's just too darned expensive. Even relatively simple designs are out of our reach right now, if you have to manifest them in real designs with real safety margins and real practical applications, such as being dockable.

vixen99 10y ago

'no long term future for us in space without something like artificial gravity.' and without an answer to the radiation problem. http://www.wired.com/2014/04/radiation-risk-iss-mars/ http://www.wired.com/2014/04/radiation-risk-iss-mars/

mkstowegnv 10y ago

Except for Venus with .9 Earth gravity and where colonies floating above the clouds have many advantages over, and may be no more difficult to create than, colonization schemes for Mars or anywhere else in space/away from Earth. https://en.wikipedia.org/wiki/Colonization_of_Venus#Advantages https://en.wikipedia.org/wiki/Colonization_of_Venus#Advantag...