[HN Gopher] Space anemia
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       Space anemia
        
       Author : feross
       Score  : 49 points
       Date   : 2022-01-14 17:32 UTC (5 hours ago)
        
 (HTM) web link (arstechnica.com)
 (TXT) w3m dump (arstechnica.com)
        
       | DrammBA wrote:
       | Definitely makes you wonder how dependent the human body is to
       | gravity.
       | 
       | Would be interesting to run these tests on different groups
       | experiencing varying degrees of gravity, on a spinning station
       | perhaps, and see what's the minimum amount of gravity we can get
       | away with while keeping side-effects to a minimum.
       | 
       | Long term tests would also be very valuable, 1-2 years.
        
         | bena wrote:
         | Gravity is probably the big one as it is the hardest to
         | approximate in space, but we're likely dependent on a lot of
         | stuff that exists on Earth. We evolved to live on Earth. Earth
         | may not be particularly suited for life, but what we consider
         | life may be particularly suited for Earth.
        
         | R0b0t1 wrote:
         | There may be processes that use gravity to either sort proteins
         | or concentrate chemicals. I can't think of much else, besides
         | hormone response to stress caused by gravity.
        
         | chinathrow wrote:
         | Scott Kelly spent a year on the ISS while his twin brother Mark
         | stayed on the ground for comparison studies.
         | 
         | https://www.nasa.gov/twins-study
         | 
         | https://en.m.wikipedia.org/wiki/Scott_Kelly_(astronaut)
        
         | ginko wrote:
         | I really feel like it's high time we try a rotating wheel space
         | station to see if the artificial gravity fixes problems people
         | develop in zero gravity.
        
           | dwohnitmok wrote:
           | My impression is that a rotating wheel space station, while
           | theoretically well within the grasp of current engineering
           | ability, would be _extremely_ expensive given that we 've
           | never done it before.
        
             | TheDudeMan wrote:
             | And that it's big and heavy.
        
             | bjelkeman-again wrote:
             | These guys are planning to fly a prototype in 2023.
             | https://orbitalassembly.com/
        
       | xwdv wrote:
       | Not a doctor but perhaps we can give astronauts some sort of
       | coagulants.
        
       | pgt wrote:
       | Aren't blood cells made in our bones? If yes, it seems reasonable
       | to assume that anything which affects bone density would also
       | affect blood cell production, no?
        
         | 420official wrote:
         | The post contends that there's an increase in destruction and
         | not a decrease in production.
        
       | kderbyma wrote:
       | probably the EM field of the earth causes the blood to polarise
       | in the correct way for iron to work properly
        
       | viburnum wrote:
       | Eventually people will come to realize that humans don't belong
       | in space.
        
         | detritus wrote:
         | Eventually people will come to realise that humans don't belong
         | above 36degN.
        
           | toss1 wrote:
           | If we don't get a handle on climate change, that statement
           | will be that humans don't belong below 36degN (and 36degS)...
        
             | detritus wrote:
             | That too, which is why we need to get crypto-mining off-
             | planet, stat!
        
             | boringg wrote:
             | We are completely off the rails on climate already. Best we
             | can do is mitigate the full extent of the damage but our
             | politicians can't quite pull it together.
        
       | eps wrote:
       | Kinda puts 9 months needed to get to Mars into an interesting
       | perspective.
       | 
       | Is there a "fast fix" for treating anemia? Because if humans do
       | get there and land on a surface, this _will_ probably be
       | required.
        
         | lapetitejort wrote:
         | Anemia is just one of a myriad of problems humans would face on
         | a Mars trip. My chief concern, and the one that's probably
         | hardest to tease out, would be the psychological stress.
         | There's no escape pod, no truncated emergency schedule, no one
         | to greet you on the other end, and potentially not enough work
         | to keep you busy. These conditions are hard if not impossible
         | to replicate on earth.
        
           | skulk wrote:
           | If stress is such a problem, then why not just sedate the
           | passenger? Some forms of sedation can be quickly reversed as
           | a last-ditch effort if there's a problem that the
           | computer/mission control absolutely cannot solve.
        
             | 420official wrote:
             | Astronauts on the space station work out nearly every day
             | for several hours to stave off atrophy and still have
             | issues. Leaving someone sedated for months in a zero G
             | environment would make the atrophy far worse.
        
           | _tom_ wrote:
           | > These conditions are hard if not impossible to replicate on
           | earth
           | 
           | Really? Where have you been for the last two years?
           | 
           | On the other hand, it does fully supports your hypothesis
           | that the psychological stress will be huge.
        
             | lapetitejort wrote:
             | The majority of people who had prepared for the 2020 snap
             | study elected to drop out after only a few weeks. Science,
             | and humanity as a whole, are worse off as a result.
        
             | RavingGoat wrote:
             | It seems like death row inmates would be a good comparison
             | group.
        
         | Tuna-Fish wrote:
         | > Kinda puts 9 months needed to get to Mars into an interesting
         | perspective.
         | 
         | It doesn't take 9 months to go to Mars. It's true that the
         | idealized Hohmann trajectory to Mars takes ~8.6 months, but
         | reality is both a lot more messy and more amenable to
         | optimization.
         | 
         | Just to take this year's launch window as an example:
         | 
         | The absolute lowest launch Dv trajectory is about 390 days, at
         | 3.73km/s. This is obviously unworkable.
         | 
         | However, if you limit yourself to the lower, faster half of the
         | porkchop plot, you'll find that the lowest Dv trajectory is
         | ~200 days, at 4.3km/s.
         | 
         | If you are willing to spend 5km/s, you can bring the trip time
         | down to ~150 days.
         | 
         | And if you have a fully retanked starship in orbit
         | (assumptions: 250t mass at burnout including payload and
         | landing fuel, 1200t tanks, 365s average Isp. These are very
         | conservative, and will probably all be improved upon before any
         | trip to mars is realistic.), which nets you 5615m/s, you can
         | push that down to 130 days.
        
         | bena wrote:
         | Anemia isn't a disease in and of itself, it's a symptom of
         | something else. You don't treat anemia, you treat what's
         | causing the anemia.
         | 
         | From reading the article, we don't know why it's happening. So
         | we don't know how to treat it yet.
        
         | JamesBarney wrote:
         | EPO is a medication that increases the number of red blood
         | cells.
        
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