No immune system....oh crap!

redhorizons · 2005-10-12 16:12:32

http://www.scienceblog.com/cms/microgra … genes_9069

This is a link to a blog talking about microgravity and our decreased immune system.
Even more of a reason to find a way to generate artificial G for a Mars mission.

GCNRevenger · 2005-10-12 16:33:21

Well... I think that settles it. Some kind of artifical gravity system is an absolute nessesity if this can't be fixed with drugs.

Are they sure that the immune system doesn't perk back up after exposure? Any Mir/ISS work done in T-cell production?

noosfractal · 2005-10-12 17:08:32

Well... I think that settles it. Some kind of artifical gravity system is an absolute nessesity if this can't be fixed with drugs.

They'd be some interesting drugs.

Why is there resistance to artificial gravity anyway? Just because it is another thing that can go wrong? Or does it make lots of things more difficult?

Are they sure that the immune system doesn't perk back up after exposure?

Everything I've read said that the only long term effect of low gravity was bone loss, which takes lots of work to reverse.

Commodore · 2005-10-12 19:52:36

Perhapes even more conserning, if the function of these cells is tied to gravity, is it tied Earth's gravity?

Why is there resistance to artificial gravity anyway? Just because it is another thing that can go wrong? Or does it make lots of things more difficult?

The expense, or precieved expense. It would involve lots of launches and on orbit construction that basically requires the ship be designed to be reusable, or be disassembled and landed to make a base, both of which make things complicated. Thanks to the ISS this makes people cringe. And if it were being done 20 tons at a time at a half billion dollars per launch, I'd cringe too.

But thankfully its far more apt to be done 120+ tons at a time at a cost of maybe $200million per launch.

GCNRevenger · 2005-10-13 07:49:28

If we did need artifical gravity, we would obviously do it Bob Zubrin style (at least initially) which wouldn't require any massive space construction. It would, however, be one big thing that could go wrong if the cable broke or the RCS system malfunctioned. It would also complicate solar arrays (which now must sustain G-loadings) and communications dishes. It also, over all, is just not as simple and trouble-free as doing without... of course, if the immune problem is persistant, then trading technical complexity for crew health will be an equitable arrangement.

If the immune response problem is due to a chemical signaling problem (a chemical being released to tell certain cells what to do) rather then a mechanistic problem (certain cells won't work in zero-G), then if we can synthesize and deliver that chemical to the appropriate organs then the problem can be fixed with drugs.

SpaceBull · 2005-10-13 08:32:55

We do not need artificial gravity. The people within the space ship will already have been exposed to all the diseases present in their ship before their immune systems starts to deteriorate. The trip to Mars is not that long either, and human t-cells have a lifespan of 20 years.

Grypd · 2005-10-13 08:41:53

We do not need artificial gravity. The people within the space ship will already have been exposed to all the diseases present in their ship before their immune systems starts to deteriorate. The trip to Mars is not that long either, and human t-cells have a lifespan of 20 years.

We carry the problem with us and the immune system protects the body from more than just viruses. The immune system stops cancer and the various bugs naturally found in a human body to keep in control. Immune system gets damaged and these can go out of control.

This can lead from constant stomach acid complaints to cancer

So now we just have to ask how much gravity is needed to keep the immune system working and the best way to provide it.

SpaceBull · 2005-10-13 08:55:39

If we consider this a problem then the obvious solution is to have astronauts take a long break on Mars before they climb into their spaceship and go back again, not to introduce artificial gravity. The human immune system will most likely be able to adapt to the Martian gravity, but this obviously depends on the age of the astronauts. The younger they are, the more sure we can be on that they will adapt.

redhorizons · 2005-10-13 09:03:32

Grypd, you are asking the right question. Now that we know that we need Artificial Gravity, we need to find out how much. I know there have been discussion on how much G we need to make the transition for Earth to Mars good just on a comfort and adapation standpoint. But the question now is about our Immune system.
Is the human immune system so connected with it's evolution of Earth that it will only function to its fullest on Earth? If so then is it possible to develop a treatment to counter the change in G on Mars?
Or is it as simple as determining at what level of G does the immune system stop working.

SpaceNut · 2005-10-13 09:17:05

Is the lack of gravity the only cause for loss of one's immune system or are there others such as radiation?

redhorizons · 2005-10-13 09:26:14

I am sure radiation does not help any, but the study was looking at the effect of microgravity specifically.

GCNRevenger · 2005-10-13 11:53:52

If extended zero gravity does effectively "deactivate" the immune system, then it is simply impractical to expose astronauts to it for any length of time. The reason that you have a resistance to a particular disease (or why vacines work) is not because your cells become invulnerable to attack, it is because your immune system can recognize the disease organism (or cells that are subverted by them as with virii) and destroy them before they can multiply.

And, as Grypd pointed out correctly, cancer is the other biggie... much like a cell subverted by a virus and reprogrammed to reproduce, cancer also fucntions likewise except that it reproduces directly and arises from normal healthy cells with damaged DNA. Almost everyone will, at some time, get one (or more!) cancers over their lifetimes; the reason why we don't all get afflicted with it is because the immune system usually recognizes the haywire cells and destroys them.

With both of these capabilities essentially shut down by zero gravity exposure, even over short time scales like the Apollo missions (two weeks), then this is a show-stopper problem if the immune system doesn't quickly adapt and "reinitialize" or be tricked into doing so. We can't lock astronauts together in such an enclosed space and expect clenliness and air filtration to protect them from biological agents, that is definatly a battle already lost. Similarly, I wouldn't even want to expose the crews to normal cancer risks without a functioning immune system, much less the much higher risk environment with the known highly cancer causing cosmic radiation which we can't block 100%.

If this effect is not temporary and short-lived while the crew adapts to zero-gravity, and no synthetic means of jump-starting the immune system chemically, then there appears to be no alternative but to give Mars ships artifical gravity. It also should give the ISS management pause to think about ways to mitigate pathogen and cancer risks. If we are going to hang onto the ISS, this might be a worthwhile question for them to work on answering... remove and freeze blood samples on a regular basis might do the trick?

Oh, and if the article is right about the "hunch" as to why this happens, then you shouldn't need full Earth gravity to maintain at least some immune function if all you need is a little pull to organize cellular structures.

redhorizons · 2005-10-13 11:59:50

Very good points GCNRevenger. This whole concept really puts a lot of wholes in current theories for Mars missions. The big Mars CEV sounds like it will not be feasible now.

GCNRevenger · 2005-10-13 12:01:39

If "big Mars CEV" means something like the NASA DRM vehicle, then they could make artifical gravity MarsDirect style without a huge amount of trouble.

redhorizons · 2005-10-13 12:29:20

I was thinking of the propossed NASA CEV that they are talking about making into a 8 person vehicle for a Mars mission.
I guess I have to research to do to learn what the DRM is.

SpaceNut · 2005-10-13 12:35:08

All of which the means to create gravity even in burst maybe enough to resolve the issue through exercise such as in this method. Which I posted in the
Long duration Human space missions - Can we survive them? thread on page 9.

Here is that post:
We know that the muscle lose and so do the very bones to which are there under laying strength over time in 0 g . But what if there were a way though exercise...

Space Cycle tests artificial gravity as solution to muscle loss

A bike-like centrifuge that creates artificial gravity may help astronauts combat muscle atrophy in space. Through a study at the University of California, Irvine, the National Space Biomedical Research Institute (NSBRI) is exploring the concept of a Space Cycle for inflight resistance-training exercise.

Commodore · 2005-10-13 13:06:30

If we did need artifical gravity, we would obviously do it Bob Zubrin style (at least initially) which wouldn't require any massive space construction. It would, however, be one big thing that could go wrong if the cable broke or the RCS system malfunctioned. It would also complicate solar arrays (which now must sustain G-loadings) and communications dishes.

You'd never get anyone to spend any serious money on something like that.

GCNRevenger · 2005-10-13 13:23:44

NASA DRM-III plan
NASA DRM-I plan

I think the DRM-III plan, with some small changes perhaps, offers the most practical missions to get to Mars without dangerously small & optimistic mass margins (like MarsDirect), enough size and payload for maximum capability for nominal cost (unlike MarsDirect), plus has potential for future use as a reuseable crew cycler (also unlike MarsDirect). It also avoids the dangers of direct no-abort departure (like MarsDirect) with time for diagnostics on orbit, and overall I think is a more realistic plan than MarsDirect.

However, Bob Zubrin's method for making artifical gravity isn't outlandish, it could probobly be done without an excessive amount of trouble. It would cost a little bit, but if zero gravity is a show stopper, it could be done.

Considering how slow most biological processies are, I doubt that "burst" gravity will be sufficent to avoid the immune issue.

Austin Stanley · 2005-10-13 13:45:58

Ptth... nothing to see here. People have spent quite some time in space and no one has died from any diseases in space. Primarily because after Launch the LSS is closed to outside micro-orginisims. If it didn't launch with them, they aren't going to be exposed to it, hence it poses no danger to their immune system.

That said, pleanty of people here on Earth (a germ laden enviroment if ever there was one) live active lives despite compromised immune systems. People with AIDS or taking immuno-suppresent drugs. In comparision a spacecraft is a very clean, nearly sterile enviroment if properly managed. In any case modern anti-biotics can cure most bacterial infections and anti-viral drugs are making good progress against viral ones.

There are plenty of reasons to be worried about microgravity. But I think the immune system is the least of them.

SpaceNut · 2005-10-13 13:56:48

Well the last ISS crew to go aboard is during research as we speak as indicated by this older article:
New ISS crew to continue experiments on HIV/AIDS vaccine and a few others.

This is also to be the third space tourist on this flight, Olsen is not afraid. He believes in Soyuz.

GCNRevenger · 2005-10-13 14:09:52

Ptth... nothing to see here. People have spent quite some time in space and no one has died from any diseases in space. Primarily because after Launch the LSS is closed to outside micro-orginisims. If it didn't launch with them, they aren't going to be exposed to it, hence it poses no danger to their immune system.
That said, pleanty of people here on Earth (a germ laden enviroment if ever there was one) live active lives despite compromised immune systems. People with AIDS or taking immuno-suppresent drugs. In comparision a spacecraft is a very clean, nearly sterile enviroment if properly managed. In any case modern anti-biotics can cure most bacterial infections and anti-viral drugs are making good progress against viral ones.
There are plenty of reasons to be worried about microgravity. But I think the immune system is the least of them.

I am not so confidant... the assumption that no pathogen will accidently be introduced into the vehicle seems to me to be kind of foolhardy over the long haul before big Galactica-type ships with artifical gravity are available. Antibiotics, while good, only mitigate this risk as well. How much of an antibiotics' affect is due to supplimenting rather then replacing the immune response? Whoops, the NASA kitchen staff didn't cook that fish long enough, now the crew is going to get sick or even die, or whoops one of the assembly technicians with the flu wiped his nose with his hand and contaminated one of the crews' stateroom door knobs... etc.

Then there is the cancer issue, that the combination of radiation and zero-gravity impared immune response may well prove to be a show stopper on its own. Note that nobody has ever spent any appreciable time outside Earth's Van Allen belts and bombarded by cosmic rays.

I would say that this is now the #1 or #2 health-related worry for potential Mars crews.

Grypd · 2005-10-13 14:37:28

I have to agree with GCNRevenger we have had long duration astronaut missions but these where in LEO and as such they where heavily protected by the Van Allen belt.

So now whatever is decided for missions to Mars we will have to provide a means to copy gravity. But it still leaves the question at what level gravity can a persons immune system be made to work and at what level of protection will it give. I think we will discover that just gravity and not neacassarily terran commen is enough a feeling of up and down. If that is the case then our jobs will be a lot easier and our astronauts safer.

GCNRevenger · 2005-10-13 14:43:02

I have to agree with GCNRevenger we have had long duration astronaut missions but these where in LEO and as such they where heavily protected by the Van Allen belt.
So now whatever is decided for missions to Mars we will have to provide a means to copy gravity. But it still leaves the question at what level gravity can a persons immune system be made to work and at what level of protection will it give. I think we will discover that just gravity and not neacassarily terran commen is enough a feeling of up and down. If that is the case then our jobs will be a lot easier and our astronauts safer.

If we can find a chemical means of stimulating the immune system in place of gravity, then we could get away without it, but unless such a drug can be cooked up then this is a major factor on top of the psychological and Mars/Earth gravity-readiness bennefits which I think tips the scales. Artifical gravity Zubrin-style should be a baseline feature based (mostly) on the cancer and (less so) pathogen risk.

Austin Stanley · 2005-10-13 15:50:04

I am not so confidant... the assumption that no pathogen will accidently be introduced into the vehicle seems to me to be kind of foolhardy over the long haul before big Galactica-type ships with artifical gravity are available.

Perhapce some pathogen's will contaminate any non-sterile vessle, but the amount will be so vanishingly low that it can probably be ignored. Bacteria and viruses are primarily trasmitted via some sort of infectious material (mucus and what not) or something that was contanimated by the material and not properly cleaned. This should not be an issue on a clean spaceship. And without contact with new inficted people there is little chance of any new pathogen's being introduced into the enviroment. Infectious diseases don't just spring out of nothing or rain down from the sky, they are transmited from person to person (or animal to person). People generaly just don't get sick spontaniously, they catch the infection from someone else.

Antibiotics, while good, only mitigate this risk as well. How much of an antibiotics' affect is due to supplimenting rather then replacing the immune response?

The effects of antibiotics are wholy independant of the immune system. Antibiotics generaly destroy cell walls of bacteria causing them to disolve and be devowered and filtered by the body. Certianly the body's immune system benifits from the weakening of the infection, but the two operate independantly of eachother. Perhapce you are confusing them with antibodies, a critical componet of the immune system?

Whoops, the NASA kitchen staff didn't cook that fish long enough, now the crew is going to get sick or even die, or whoops one of the assembly technicians with the flu wiped his nose with his hand and contaminated one of the crews' stateroom door knobs... etc.

I seriously doubt that food poisning is going to be an issue, all the food brought on board must be preserved in some way (freezdrying primarily) that prevents the transmition of infectious material. And while accidental contamination is a risk, it's a minor one. Very few people catch colds from infected doornobs, it's just not a good disease tranfser mechanisim. Simple cleanlyness, like washing hands before and after meals, restroom, and proper clean-up of food and what not also drasticly lowers this risk. So while a risk of infection may exists, it's extreamly low.

Then there is the cancer issue, that the combination of radiation and zero-gravity impared immune response may well prove to be a show stopper on its own. Note that nobody has ever spent any appreciable time outside Earth's Van Allen belts and bombarded by cosmic rays.

Cancer doesn't just develop overnight. Rember that the ride out and back aren't very long from that point of view. Also, the concurns with the immune system seem to be confined to T-cells and their roll in fighting infectious disease, not the body's ability to recognize and eliminate cancerous cells, which is seperate. Cancer is not a primary worry of AIDS paitents who suffer similar (although probably more sevear) T-cell deficencies.

And while no one has long term exposure to cosmic radiation, it's not like it is any diffrent than any other sort of radiation of similar magnitude. And the data we have on that shows that the increased risk of cancer is mild (<10%) and the chances of developing it spontaniously during the mission slim to none.

-----------

Key points.
#1. A spacecraft should be a very clean enviroment, there is little infectious material to come in contact with and this material (and the kinds of infectiouns) will not change over the duration of the mission.
#2. The concurns are primarily with T-Cells which fight infectious diseases, not cancer. Cancer developes over a longer period of time anyways.
#3. The body has several layers of immune defense not reliant upon T-Cells which will still be effective. Our primary (and most effective) line of defenese, out skin and mucus membranes are not effected at all.
#4. Many people on Earth live active lives despite similar T-Cell deperesion due to AIDS or other immune disorders, some self inflicted (for transplants).
#5. Antibiotics, which can cure practicaly all bacterial infections, and antivirals can also help to support/suplant the human immune system if necessary.

Grypd · 2005-10-13 17:19:57

Perhapce some pathogen's will contaminate any non-sterile vessle, but the amount will be so vanishingly low that it can probably be ignored. Bacteria and viruses are primarily trasmitted via some sort of infectious material (mucus and what not) or something that was contanimated by the material and not properly cleaned. This should not be an issue on a clean spaceship. And without contact with new inficted people there is little chance of any new pathogen's being introduced into the enviroment. Infectious diseases don't just spring out of nothing or rain down from the sky, they are transmited from person to person (or animal to person). People generaly just don't get sick spontaniously, they catch the infection from someone else.

yes but spaceships in microgravity are really difficult places to keep clean when they are in use the place gets covered in dead skin cells hairclippings and there is the ever present moisture and spilt food. In short a haven for all bugs. And the viruses and germs we will find will be carried on board all right that is aboard inside the astronauts

Then there is the cancer issue, that the combination of radiation and zero-gravity impared immune response may well prove to be a show stopper on its own. Note that nobody has ever spent any appreciable time outside Earth's Van Allen belts and bombarded by cosmic rays.
Cancer doesn't just develop overnight. Rember that the ride out and back aren't very long from that point of view. Also, the concurns with the immune system seem to be confined to T-cells and their roll in fighting infectious disease, not the body's ability to recognize and eliminate cancerous cells, which is seperate. Cancer is not a primary worry of AIDS paitents who suffer similar (although probably more sevear) T-cell deficencies.

We are not talking short durations are we this is 6 months or more in a high radiation enviroment without an immune system. And it is hard to check to see who actually will suffer the effects as people are different and what one person can shrug off another will fall ill too.

And while no one has long term exposure to cosmic radiation, it's not like it is any diffrent than any other sort of radiation of similar magnitude. And the data we have on that shows that the increased risk of cancer is mild (<10%) and the chances of developing it spontaniously during the mission slim to none.

But if this study is proved correct this previous rendering of risk is no longer valid. It is based upon a healthy person with an active immmune system and what the effects of radiation exposure would do to that person. This is from data compiled on Earth from the results of the nuclear tests. But if we then go to space and discover that gravity and its lack causes immune deficiences in a severe scale as this report seems to say then that means simply risk is increased and by a lot more than a factor of 10% over a lifetime. Worse is that it is the immune system that fights the damage radiation exposure does and so the effects of an increased dose is now also magnified.

But in the final thought about this I do not believe that it is as bad as has been made out but this report and the effects of microgravity will be used against the manned space program so it is best if we work out the worst case scenario and find a means to ensure that the effects of too long in micro g are removed. There is a lot of people out there who would like to stop manned spaceflight and im sure they will use this report to try to damage the plans for visits to the Moon and Mars.

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