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All this could be avoided by fully implementing artificial gravity on deep-space journeys. This should not be particularly difficult and would involve just taki
by iwwr 11y ago
All this could be avoided by fully implementing artificial gravity on deep-space journeys. This should not be particularly difficult and would involve just taking the last rocket stage along for the ride, tied to a tether. Rotate to produce gravity.
Even if the zero-g journey to Mars is uneventful, astronauts will be severely weakened by the time they arrive there, even with heavy exercise and preventative measures. And in the first few weeks they actually do the most and heaviest work.
So there's a little mystery why NASA insists on trying to find a pharmacological or mechanical workaround when artificial gravity is right there.
- moron4hire 11y agoIDK, considering they have a lot more people working on the problems than just some guy on the internet, I'm assuming they have good reasons.
- techdragon 11y agoOne is mechanical engineering but the other generates thousands of valuable research papers each year. Research papers that prove NASA are doing their job. The other simpler way requires expensive in orbit construction to do anything in the way of research.
- iwwr 11y agoMind you, I'm not against research in either drugs or mechanical solutions (better exercise machines), but they could serve as backup in case the main system - centripetal acceleration - is malfunctioning. One question NASA has yet to answer is the minimal level of gravity necessary to prevent muscle and bone degradation. Is the Moon or Mars human-habitable in terms of gravity? If that's not the case, then mission plans would have to include rotating habitats for planetary surfaces, which makes matters a little more complex.
- AndrewKemendo 11y agoYou're joking right? A quick google search returns hundreds of resources from nasa.gov about research into bone and muscle degradation.
- coldtea 11y agoHundreds of resources from nasa.gov regarding research into bone and muscle degradation don't automatically translate to what the parent asked for, for NASA "to answer (...) the minimal level of gravity necessary to prevent muscle and bone degradation".
- AndrewKemendo 11y agoIt's probably the wrong question was my real point.
- eximius 11y agoIs there one? I imagine it is a proportional effect. You'd experience degredation at .9g, it just wouldn't be nearly as bad. The more interesting, and difficult I'd wager, is what is the minimum healthy level.
- coldtea 11y agoLots of things in large organizations are done for political, budgetary, turf-war, ideological and finally idiot-in-charge reasons, not necessarily for "good reasons".
- deelowe 11y agoHow do you propose this would work actually? The last article I read on the subject suggested that AG isn't viable near term as the space craft would have to be prohibitively large. I recall the primary issue being that living quarters have to be a certain distance from the axis of rotation. [EDIT] Here you go. The relevant info is on wikipedia: https://en.wikipedia.org/wiki/Artificial_gravity#Rotation https://en.wikipedia.org/wiki/Artificial_gravity#Rotation The radius of rotation would have to be a minumum of 224 meters.
- slfnflctd 11y ago...meaning a diameter of almost half a kilometer, or over a quarter mile-- more than four times the longest part of the current ISS, which took over 12 years and 150 billion dollars (and is essentially flat when compared to the cylinder shape needed for AG). I can see why this might be a bit of a challenge, the time and costs involved would be enormous.
- iwwr 11y agoSee my reply here: https://news.ycombinator.com/item?id=10649760 https://news.ycombinator.com/item?id=10649760
- pavel_lishin 11y agoWhy would you need a full cylinder? Living quarters on one side, (rocket stage) counterweight on the other, tether in between. You'd probably want all that stuff reeled in together for acceleration and deceleration, but you can unspool the whole thing while you're coasting in between.
- Xylakant 11y agoso how do we stop the rotation while reeling in for acceleration? Shortening the tether would accelerate the objects at the end and we'd end up with a rotating drum filled with seasick astronauts. I sincerely doubt it's that easy.
- creshal 11y agoYou make it sound like tethering in space is a solved problem – it isn't: https://en.wikipedia.org/wiki/Space_tether_missions https://en.wikipedia.org/wiki/Space_tether_missions Reliable reeling mechanisms that actually work in vacuum seem a yet unsolved problem, and there's occasional research into it. Sure, there could be more, but it's not like the lack of gravity is the only (medical) problem to solve for a Mars flight.
- troutwine 11y agoOh shoot, I accidentally downvoted you when I meant to upvote. Terribly sorry! Parent commenter presents this idea occasionally without justification. At present stage of research, as you correctly point out, tethering in space is further out than biomedical research.