Space Faring: The Radiation Challenge - Nasa: Fill & Download for Free

NASA funds research programs devoted to studying a variety of aspects of living in space including the physical effects on the human body in a zero-gravity environment.Pregnancy and birth in space...A human baby has yet to be born in space; no pregnant women have even traveled in space as yet. A number of studies have sent pregnant rats into space so the development of the babies could be investigated. The rats merely traveled to space and the babies were born back on Earth. In 1983 the Soviet Union launched a satellite with a pregnant rat on board and found the trip was harder on the mother than on the fetuses. Once the babies were born they were slightly thinner and weaker than their fetuses that didn't travel to space. They also lagged behind in their mental development, but eventually caught up. The mother lost a quarter of her body weight and had notable changes in her hormonal and endocrine systems.In 2001, NASA sent 20 pregnant rats into space to determine some of the effects the zero-gravity environment had on the fetuses. The rats were sent in the middle of their pregnancies when the vestibular (inner ear, balancing) systems were beginning to develop in the fetuses. The experiment was meant to vaguely mimic research done in the 1960s on humans that determined a certain amount of light and sound stimuli were necessary during crucial periods of pregnancy to develop vision and hearing in the baby.The mothers and babies fared much better in this experiment than in the 1983 study. The mothers gave birth to normal-sized babies and were able to lactate and care for them normally. Even after the muscle mass lost due to the lack of gravity the labor contractions did not pose a problem for the mothers. There were noticeable effects on the vestibular systems of the space-based rat infants, however. The Earth-based babies were able to immediately right themselves upon being turned on their backs in water. The space-based babies had more trouble; some had to make a few attempts before achieving success and others were unable to do it at all. Again, they eventually caught up. The researchers also determined that the vestibular organs detecting angular changes were actually more advanced in the space-based babies, probably because their mothers were forced to roll around a lot on the shuttle due to the lack of gravity.Radiation is also another consideration for space pregnancies. A human birth in space may be a ways off, but the findings so far seem promising. No doubt the first space-mom will have to be very healthy and in great shape.What if you were born in space?Living in space...This is highly dependent on where a space-borne individual would actually live. Since we're talking about the ISS, which has a relatively low orbit, gravity isn't much of a problem. The residents of the ISS are in a zero G environment, but they're still subject to the gravity of the Earth. So what problems happen to people who spend time on the space station? They all have visual problems. Everyone is tested back on Earth, and their ability to see is always affected. An astronaut can even lose about 22% of their total blood volume while in space. Also the radiation from the sun and the rest of the universe can be dangerous for the human body and we are still not sure how to safe guard ourselves from these radiations.Bones are affected too. An astronaut can expect to have their spine expand up to three percent. This weird effect adds an inch or two to a person's height. Since muscles are not needed as much to move around because of the weightless environment, astronauts find that their muscle strength is weakened. This is the reason for the daily exercise regimen.A more serious issue is space-borne osteoporosis. Astronauts lose, on average, one percent of bone mass per month. Excessive bone loss and the associated increase in serum calcium ion levels will result in irreversible skeletal damage. According to Wikipedia:Bone loss has been observed during spaceflight since at least as early as Gemini in the 1960s. Although most early measurements of the amount of bone loss were not reliable, they did show bone loss in Gemini, Soyuz 9, Apollo, Skylab, Salyut 7, Mir, and the International Space Station. William E. Thornton, an astronaut and physician, was one of the biggest proponents of exercise as a way of preventing bone loss.So, overall, while there's still so much we don't know, it's clear that living in space poses some real challenges. If the bone-loss and radiation problems can be resolved satisfactorily, a person who is born and lives their entire life on the ISS may very well outlive a human on the Earth. One thing we do know is that there are no cars, wild animals, or serial killers in space... yet.

It's generally agreed in the subject of Planetary Protection that we shouldn't colonize Europa. The problem is that it is such an interesting place for life, and there is a reasonable chance it has native lifeforms. And with a surface of ice, global subsurface ocean, and water plumes, any landing of humans there obviously has a significant risk of contaminating it with Earth life.Even if it doesn't have life, we would want to know what it is like without introducing Earth life first. Does it have complex chemicals? Does it have DNA? Or XNA, or TNA not yet in the form of life? Does it have nanobe sized proto lifeforms? Or what happens to a global ocean rich in oxygen like Europa left to itself for billions of years? We will certainly want to know that before even considering sending humans there. And some scientists think we have a responsibility to keep Europa clear of Earth life not just for ourselves, for future studies in the next few decades or centuries, but for all future time. So even once we have studied it, and have a rough idea what it is like and if it has life, there would be many who would say we shouldn't colonize it.Mars is a bit different, there some people think that the surface is so sterile that human exploration wouldn't make a significant difference for planetary protection. While others say they would. This would have to be resolved before we send humans to the surface of Mars.But in the case of Europa, everyone is in agreement, in the planetary protection workshops discussing it. To the extent that they also take great care to make sure that none of the unmanned spacecraft sent to the Jupiter system have any chance of crashing into Europa. At the end of the spacecraft lifetime you have to show that it can't do that.In any case the surface levels of radiation for Europa are so high, because it orbits right within the Jupiter version of the Van Allen belts which are also stronger than for Earth. The radiation would kill humans within hours. So - not an ideal place for humans. Yes would be protected in the ocean, but we wouldn't want humans there anyway.Any humans in the Jupiter system would be further out, perhaps Callisto. Which has an ancient surface, no evidence of activity. Less radiation anyway, it's just outside the main radiation belt for Jupiter. And it may well have a subsurface ocean also, but it does not communicate with the surface as far as we know.Or else, just orbiting Jupiter in an orbital settlement.At any rate Jupiter is tough of access. Hohlman transfer getting on for two years, see Voyager - JupiterBefore we can consider sending humans there, we need them to be able to survive long term, without resupply, in closed system habitats for a couple of years in space at least, preferably a lot longer for a safety margin. We are nowhere near that capability yet. Will soon probably have the capability to send the launch mass to Jupiter, but to actually survive the journey there is another thing altogether.So not a thing we need to decide soon, how humans can survive in Jupiter orbit. Though there are people who are really keen on sending humans to the Jupiter system.There is even, apparently, a group of people who want to do a one way manned trip to Europa.I think, you are right, that once you get to Europa and if you can bury yourself beneath the ice quickly enough, within minutes of arrival on the surface, you'd be better able to survive there than on Mars. Because the advantages of an oxygen rich ocean, at temperatures similar to an Earth sea would be hard to beat, comparable probably to living permanently in an Earth sea or an Antarctic subsurface ice lake perhaps. I mean you'd never colonize such a place on the Earth but as you say - it would be a great analogue of Europa.Move over, Mars: Manned Europa mission considered - CNETBut no way would these proposals pass planetary protection as mandated in the Outer Space Treaty signed by all space faring nations, and aspiring ones (even N. Korea), and just about all other nation states also. As with Mars missions, then often the enthusiasts give little consideration to the subject.But before such a mission could be launched, those concerned would need to satisfy the rest of us that they are taking adequate planetary protection precautions, and would not contaminate Mars, or in this case Europa with Earth life. And this is a responsibility of the governments of both the state they are citizens of, and the state that provides the launching platform and rocket components, all those involved. And doesn't matter where they launch from, the responsibility extends to their activities once they are in space also.E.g. all Elon Musk's activities in space are the responsibility of the US government, to make sure he keeps to planetary protection policies. In case of Mars One launching using US rockets, it's responsibility of both Netherlands and the US, and also the governments of all the countries that have citizens taking part in the mission to make sure that it complies with the planetary protection policies. No matter where they launch from. They have none of them suggested that they intend to breach these international laws anyway, I hasten to add.In the case of Mars there is the idea of an "exploration phase" which however keeps being extended, the idea that at some point we may know enough about the planet so that we don't need to keep it pristine any more for scientific study. With some scientists saying it should have no end date.So space colonization enthusiasts who want to send colonists to Mars may think that at some point we will know enough about Mars to have finished this "exploration phase". Or they may think that we will find out that the surface of Mars is so hostile that no Earth life can survive there unprotected (that of course would also make it very hostile for humans also).In the case of Europa nobody in the planetary protection discussions has yet suggested it should have an "exploration phase" at all. So, despite these ideas of enthusiasts, I don't see that happening any time soon.Also as well as that - in Antarctica also they take great care not to contaminate the sub surface lakes with Earth life, because they have been isolated from the surface for so long, and they want to know what happens to life in such conditions, with no communication with surface life. Introducing surface life would confuse their findings.The Russians drilled to within a few meters of Lake Vostock and then stopped for many years as they developed the technology to go for the last few meters into the lake itself without contaminating it. And the US similarly sent their first exploration to a similar lake again taking great precautions.So just like with Europa, they would not permit humans to colonize or even explore these places yet, until they have a chance to study them, and quite possibly never.If you want to attempt colonization of space - well I'd recommend the Moon, there are no planetary protection requirements there at present as it is thought to be impossible for Earth life to survive there. And it is also a major challenge to keep humans alive even within 2 days journey from Earth, surely best to crack that one first. Or more space station type colonies.Or, my own favourite for human space exploration, a space station in the L2 position, far side of the Moon, explore the surface telerobotically - lots of science value as it is hard to study the far side of the Moon - and a challenging place to send humans, but not too challenging, easier to get back to Earth even than from the lunar surface, it's a logical next step from LEO as an interesting place to send humans that is just difficult enough to be a major challenge, but not so challenging as to be a huge safety issue for humans.The logistics even for that likely to be a major challenge - though at the worse, with improving launch capabilities we could just launch supplies there every few months as with the ISS. But to be a good precursor for interplanetary exploration, should be designed for resupply only every couple of years or so, if that is at all possible.If that can't be done, if we don't have the technology for a multiple year space station at L2, and we certainly can't do that at a reasonable cost with present day technology - I'd say that no way are we really ready for large scale interplanetary human exploration or settlement, never mind colonization.See also : Robert Walker's answer to Has NASA purposefully sent any life forms to other planets?

Physically getting them there is just part of the story. Will they be alive when they get there? Will they have any purpose for being there except to just exist? Will they eventually look back to Earth with longing and wish they lived here rather than in a place where even breathing can't be taken for granted?But the most important thing, I think, is whether he - or anyone else - is going to get permission to do so under the regulations for protecting Mars from Earth life.Suppose he wanted to send a million people to live in Lake Vostock in Antarctica under the ice? It is more hospitable than Mars in many ways - not least - that you are surrounded by liquid water. It is also the most oxygenated water on Earth probably, hyper-oxygenated. And you don't need shielding from cosmic radiation. I think much more viable place for a new colony myself than Mars - not having daylight is a minor inconvenience compared with all those advantages.But he would not be permitted to do that. Reason is because Lake Vostock has been separate from the surface for some millions of years. Even though life there is likely to be quite similar to surface life - only had a few million years of independent evolution - still - the scientists want to be able to find out what the life is like as it is now, without contaminating it with surface Earth life. They want to know what types of lifeforms manage to seed Lake Vostock naturally - and what they have evolved into, whether there is a thriving ecosystem there already - and what it is like, and how complex it is.Even if the lifeforms are almost identical to ones we already know - still - they want to know - is it exactly identical? How much has it diverged and in what ways as a result of millions of years of isolation in this cold, dark, oxygen rich environment? Contamination with surface life is a major issue for them.In the case of Mars - it is far more isolated from Earth than lake Vostock. There is a chance that some life might have made its way from Earth to Mars - but if so - just a few very hardy lifeforms - maybe chrooccocidiopsis for instance and halobacteria. Most microbes on Earth couldn't survive the transit on a meteorite to Mars, subjected to cosmic radiation and the vacuum of space. Also you only have that opportunity every few tens of millions of years when you get an impact onto Earth of a meteorite of ten kilometers diameter or more - smaller impacts don't produce debris moving fast enough to get through the Earth's atmosphere and exit from it at escape velocity. And then when the material gets to Mars it has to find a suitable habitat there - and habitats for life on Mars may be rare - and it has to be a suitable lifeform to survive in that habitat.Indeed, there are of course no confirmed examples yet of any life being transferred to another planet.So - life on Mars may be like lake Vostock - essentially same forms of life, all that is there are these cyanobacteria and halobacteria that last seeded Mars a few tens of millions of years ago. Still - scientists will want to study the life there without Earth contamination. Especially since it evolved for some tens of millions of years in an environment with high levels of cosmic radiation, and thin atmosphere, and surface rich in perchlorates and sulfates rather than chlorides and sulfides, and almost no water on the surface.But more interestingly, Mars is so isolated from Earth that it could easily have other lifeforms based on some other basis. Even - just ordinary DNA - but - with different capabilities such as - for instance new form of photosynthesis. We have just two main types of photosynthesis on Earth - the type that depends on taking CO2 out of the atmosphere, and the type used by Halobacteria which uses a method similar to the method our eyes use to see colour to generate energy more directly from light.What if Mars life has evolved some other totally different form of photosynthesis never explored on the Earth?Or - maybe life based on XNA rather than DNA? Or not spiral molecule based at all, some other way of encoding it?It could also have complex organic structures that are somewhere in between life as we know it and inorganic life. These particularly could be fragile to introduced Earth life that would just eat these structures up as food.So - for all these reasons - I think that when the time comes to it, Elon Musk simply will not get approval to send humans to Mars. Nor Mars One, nor NASA, or ESA or anyone.The planetary protection officers say that they think it will be possible. But they don't make the final decisions. The decisions are made by COSPAR workshops, international gatherings of scientists from all nations world wide. And in those workshops you'll have astrobiologists and such like who have to look at all the evidence carefully. I just don't see how they can be expected to approve sending humans to Mars until we thoroughly understand what is there and what the effect will be of introducing Earth life ot the planet.It would be different if we knew that the surface of Mars was totally uninhabitable. But we don't. Indeed there is a fair bit of evidence suggesting that there may be various habitats on the surface of Mars.Just a few droplets and thin films of water here and there, occasionally, for a few hours of the year. But that is plenty for bacteria - and complex organics for that matter in between life and non life, to thrive. For that matter - it also means that Earth life could potentially reproduce on Mars - at any rate we have not yet shown that it is impossible for it to do this.Indeed, as someone fascinated by exobiology - I personally hope that we do find life on Mars. If so - then sadly humans would not be permitted to explore the surface directly.But still we can explore it via telepresence with telerobotic avatars on the surface. Maybe in the future humans could go there if we can develop ways that spaceships and spacesuits can be totally sterilized - with the spacesuits doubling as biohazard suits that contain all Earth life within them - but is hard to see that at present with present day technology.Reason it is so hard to see that possible right now is - that apart from anything else, none of our current spacecraft could survive a crash landing on Mars if their landing system failed, and still contain all the lifeforms inside the spacecraft. It would rip open and the life would spill out over the planet - and then get dispersed in the global dust storms. It's hardly worth going on to examine whether the spacesuits and airlocks could contain Earth life.Sometimes people suggest that life in habitats would not be able to survive on Mars. But you get extremophiles everywhere. Lifeforms able to survive in reactor cooling ponds or on granite cliffs in Antarctica, or in hydrothermal vents, may also be living in your clothes, and on your skin. And 99% of the microbes in any given habitat, by number, can't be cultivated and hardly anything is known about most of the uncultivable archaea.See also my articles on Science20 such as this one for the evidence of possibilities of liquid water on Mars right now:Where To Search On Mars For Droplets, & Shallow Flows Of Liquid Water - Where Microbial Life May Flourishand many other answers here on quora.Now - there are places we can go safely - the Moon - or to create free colonies in space without this impact on scientific integrity of the missions. And we can have colonies in orbit around Mars eventually.But - personally - don't see humans on the surface for at least many decades into the future - only way that would be possible is if the surface turns out to be totally inhospitable to Earth life - and even then there would be questions to ask about whether introducing e.g. aerobes etc to Mars surface at an early stage is advisable if you ever plan to terraform it.But the way things are going at the moment - seems unlikely that Mars is totally inhospitable on the surface. At any rate unlikely that we will be able to prove that it is in the near future.For instance, this may be caused by liquid water, thin films:And this idea supported by Mars simulation experiments, that you get droplets of water forming at interface of salt and ice by Nilton Remmo, scientist for Phoenix and for the Curiosity remote weather station on Mars - the "swimming pools for bacteria"Also you have the discovery by DLR of cyanobacteria and lichens that are able to photosynthesize and metabolize in Mars surface conditions using just the water vapour in the atmosphere. You also get halobacteria in the Atacama desert that can survive inside salts (abundant on Mars) using natural microscopic pores in the salt to gather the water vapour at well below 100% humidity.So - I think we'll get many people saying that we can go to Mars, and saying that planetary protection won't be an issue. But when time comes to actually study it carefully and to decide whether to approve such a mission -after the astrobiology experts review all the evidence - I can't see COSPAR approving it myself.When that happens - I don't think, when the time comes to it, that they will want to go against the requirements of planetary protection. Certainly Mars One has said they will fulfill all their international obligations and surely Elon Musk would also. And for that matter - then the US itself, as all signatories of the Outer Space Treaty has an obligation to make sure its citizens keep to the terms of the OST. It doesn't matter how they get into space either - the US is still obligated to make sure its citizens abide by the OST under international law - Netherlands for its citizens likewise, etc. And the builders of the spacecraft and those who provide launch facilities are similarly also obliged - and everyone with space faring capabilities, or the slightest space faring aspirations, even N. Korea has signed the OST, showing that they recognize the value of planetary protection.Hopefully when that happens, these entrepeneurs will not just give up, but instead put their efforts into work on viable space settlements e.g. in orbit around Mars exploring it via telepresence.That would be awesome, to have a million people in orbit around Mars exploring it via telepresence with several million telerobotic avatars on the surface (you'd have several avatars to each person). And would most likely cost far less than sending them to the surface. It also eliminates the most dangerous phase of such a mission - landing humans on Mars. Instead you just land their avatars - and if one of those ships crashes - well you've lost a lot of expensive telerobotic avatars - but nobody has died.They could use the Martian moons for materials, or indeed the NEOs or asteroid belt or further afield, to build their orbital colonies around Mars - so long as you are in no hurry, is relatively easy to move materials from just about anywhere in the solar system to anywhere else via repeated flybys and gravity assists.I don't know if that would interest him though. Hope it would. Would be a major challenge also to do that without contaminating Mars but I think it could be done with great care and advancing technology.