Skip to comments.NASA Undeterred by the Threat of Space Radiation
Posted on 10/14/2017 9:54:09 PM PDT by BenLurkin
Space Age, scientists have understood how beyond Earths magnetic field, space is permeated by radiation. This includes Galactic Cosmic Rays (GCRs), Solar Particle Events (SPEs)
NASA is able to protect crews from SPEs by advising them to seek shelter in more heavily shielded areas of the station...
GCRs are more of a challenge. These energetic particles, which are primarily composed of high-energy protons and atomic nuclei, can come from anywhere within our galaxy and are capable of penetrating even metal. To make matters worse, when these particles cut through material, they generate a cascade reaction of particles, sending neutrons, protons and other particles in all directions.
This secondary radiation can sometimes be a greater risk than the GCRs themselves. And recent studies have indicated that the threat they pose to living tissue can also have a cascading effect, where damage to one cell can then spread to others.
NASA is currently evaluating various materials and concepts to shield crews from GCRs. These materials will become an integral part of future deep-space missions. Experiments involving these materials and their incorporation into transport vehicles, habitats and space suits are currently taking place at the NASA Space Radiation Laboratory (NSRL).
NASA is also investigating pharmaceutical countermeasures, which could prove to be more effective than radiation shielding. For instance, potassium iodide, diethylenetriamine pentaacietic acid (DTPA) and the dye known as Prussian blue have been used for decades to treat radiation sickness. During long-term missions, astronauts will likely need to take daily doses of radiation meds to mitigate exposure to radiation.
Space radiation detection and mitigation technologies are also being developed through NASAs Advanced Exploration Systems Division. These include the Hybrid Electronic Radiation Assessor for the Orion spacecraft, and a series of personal and operational dosimeters for the ISS.
(Excerpt) Read more at universetoday.com ...
If we can solve the difficulty(cost) of getting things into orbit. Then radiation won’t be that great of a hurdle.
Or we can just send out robots. Which is what we’re going to do anyways.
It is going to take centuries, and probably millennia, to figure out how to keep human beings alive, let alone comfortable, in deep space, or on other planets or moons.
And that just solves the space travel problems in our own Solar System.
Visiting other star systems means solving the speed of light problem, if that is even possible.
And the final problem - how do you make money once you leave the Earth, and where can you spend it if you do make it?
Economically, going into space is like going back in time to 10,000 BC.
Except in 10,000 BC they had free oxygen, free gravity, free atmospheric pressure, free firewood, free animals for food and clothing, free water, and free nuts and fruit.
Solar radiation can be reduced using magnetic shielding. Cosmic rays, however, can only be blocked using sheer mass. Earth’s atmosphere provides about one ton of mass per square foot. It would be difficult to duplicate this for a space ship unless it’s a real big space ship, or a large space station. Neither of these are impossible, however.
One advantage to remaining in LEO for these past 40+ years has been remaining under the relative protection of the Van Allen belts. Going through those on the way to and from the Moon wasn’t much of a challenge, because the transits only took a few minutes.
“... in 10,000 BC they had free oxygen, free gravity, free atmospheric pressure, free firewood, free animals for food and clothing, free water, and free nuts and fruit.”
and somehow no one leaned how to barter or trade, or worse sell things for markers of value (money); while living in this state of total bliss, all the predator animals and people from other groups studiously avoided conflict because everything essential was plentiful and free.
And that had been going on for the past 250,000-350,000 years of human existence - simply amazing!
“Visiting other star systems means solving the speed of light problem” assuming that there isn’t another way to move across space and time like proposed by James Clerk Maxwell in 1859 (the father of everything we know today).
Sending robots is a poor way to explore anything - one gains some information, but there is no certainty that the information received is actually correct, since it cannot be verified by an actual observer on the spot. Worse the robot can only report what it has been programmed to report: if, in an extreme example, an alien space craft were to approach the robot, the craft’s existence would go unreported because no one told the robot to be on the look out for alien spaceships. Only a human would think to report it. If robots had been used to explore the continent of Africa - that exploration would still be in its infancy today, and nothing much would be known about it beyond a few miles inland from the coast.
To explore is to take risks. And that cost money. Knowledge is not free.
Or we can just send out robots. Which is what were going to do anyways.
For the price of 1 manned mission to mars with 4 people, we can send a vast army of robots... and year by year the robots get smarter and more capable.
For the time being, the solar system will belong to robots, and the sooner we accept that the faster our robotic progress in developing the resources in the solar system for our use and application to human progress.
Prussian Blue is ferric cyanide! Ya gotta wonder about the long-term effects of consuming it!
Clearly in all the universe (no way we can know) there is one place amazingly created for man - the earth.
The complexity of the environment that protects us is almost beyond imagination - and yet - prideful man cannot see that such and environment HAD to be created. And only God could have created such an environment.
It’s fine to adventure out of our safe zone. USA would not exist if Columbus, the Puritans, and many others had not left the safety of their places of comfort. But there are limits to how far we can adventure.
Will we ever figure out how to safely travel great distances without earth’s protection? I doubt it. Not only is the hostility of space a major factor - the greatest one is time. One cannot break the laws of physics.
I know, some will say my view is similar to those hundreds of years ago who said we would never fly. But flying does not break the laws of physics - it uses them.
I doubt that we will ever be able to do that with time - in spite of all the science fiction we’ve become familiar with in the last 100 years...
Four centimeters of titanium does provide sufficient protection from almost all solar particle events or "SPE's." Counter to intuition, when the Sun is at it's most active its swelling of the interplanetary magnetic field refracts as much as 50 percent of the GCR's showering into the inner Solar System from outside. But those "GCR's" are often the very energetic stripped nuclei of iron and more exotic metals barrelling into our star system from every direction, and at near light speed. A ship-borne artificial magnetic field designed to refract such inbound GCR's would have to be initially effective beginning at 2000 kilometers distance away from a spacecraft. There is no advanced warning of their impending arrival from which one might gain shelter, unlike the risks posed by coronal mass ejections or other solar particle events.
The writers correctly admit that a four-centimeter thick titanium hull actually results in the spallation of a single heavy metal GCR nuclei from a single bullet into a shower of an only relatively less energetic shotgun shower of fragments that then pass dangerously through passengers. In other words, when it comes to GCRs, hulls that protect the crew from the dangers posed by the Sun, in the case of much more energetic and heavy GCRs, make a very bad encounter worse.
It's calculated in terms of risk, not mitigation.
Low Earth Orbit is somewhat shielded not just by our planet's relatively strong magnetic field, apparently unusual among the rocky planets of the inner Solar System, but also from proximity to the Earth itself. Like being on or near the Moon, Mars or Earth, the planet at our feet, so to speak, always provides shelter from half of the incoming GCR's. But unlike Earth, the sky above is wide open to at least half of these incoming interstellar bullets when standing on the Moon or on Mars, where an equivalent shelter might only be found 30 meters underground. It was hoped at one time that the strong highly local magnetic fields now mapped on the Moon, for example, such as the one near the landing site of Apollo 16, could provide sufficient shelter, but even though it might add to calculations reducing the cumulative risks to astronaut health, those fields don't stand off from the planetary surface the 2000 kilometers needed to begin bending away energetic GCR's in time.
For NASA's astronauts (not for its dependent industrial lobbyists and bureaucrats) the risk to health is coldly calculated in an individual passenger's lifetime risk of radiation-induced death. Flights across the poles, chest and head xrays, even exposure to radon over a person's life all go into their calculations, along with the altitude and length of earlier spaceflights. Once their periodic estimations and tables conclude that an individual astronaut's lifetime risk of eventual radiation-induced death reaches five percent, that astronaut is grounded. The simple fact of the matter is simple and stark when it comes to proposed roundtrip voyages to Mars, using present velocities and standard Holman-transfer orbit schematics. Such a trip would cross that threshold, as acknowledged by the National Research Council in 2003. It would be no more of a death sentence than a smoking habit or from being on the Fukushima clean-up crew, but enough risk for NASA to ground every crew member upon their return to Earth and in some cases prevent their being on such a crew at all.
Again, perhaps counterintuitively, older proposed crew members would have at least one advantage over youth. They are more likely to eventually die of other causes, over the shorter period of their estimated remaining lifetime. Just one more thing added to the cold actuarial calculations used to choose crew members. Nonetheless, even taking mitigating factors into account, like estimated solar activity during the time of the mission or the proposed time spent on the surface of Mars as well as life history into account, if NASA estimate's that an astronaut's ride along a planned mission into deep space will result in reaching beyond a five-percent risk of an eventual "radiation-induced death," that member won't be allowed to fly under their present guidelines and policy.
There are mitigation strategies designed to reduce if not entirely eliminate the real risks of travel to Mars, but nearly all of these involve innovation, new technologies that will need to be tested and coldly evaluated, including hull designs. It seems many of the stories appearing in industry and national press dismissing the challenge presented by GCR's is designed to address the low-information federal budget staffer and lawmaker.
Many in the space industry are hoping Congress never bothered to actually read the National Research Council's pre-Obama era studies on the subject more than a decade ago.
On the surface of a body, you solve the problem by going underground if the stay will be lengthy.
The problem with a manned mission anywhere other than the moon is your trip times are measured in months using chemical rockets. Basically, any serious proposal for going to Mars should involve nuclear propulsion to make the trip time and risk more manageable. As well as nuclear power on the surface because making consumables (air, water) on the surface will be necessary.
Also, it should be a semi-permanent self-sustaining outpost, since not just the travel time but the travel cost is exorbitant.
I don't see it in our national will anytime soon.
“Or we can just send out robots. Which is what were going to do anyways.”
I have speculated that what folks among the UFO set always describe as the “Grays”, could possibly be not the actual beings that built and send the UFOs here, but something like “biologically constructed” and programmed “robots”, engineered to withstand the riggers of the super-long voyages and the dangers of radiation. Why biological and not mechanical? It is likely easier to make a biological construct able to do self-repair than it is to make a piece of metal self-repair. The biologic robots can then also make needed “mechanical” repairs to elements of the ship showing harm from radiation. Yea, just my own silly fantasy I know. LOL
We should establish a large base on the Moon with lots of people that are supplied by a stream of supply ships from Earth.
The gravitational well on the Moon is much shallower than that on Earth. Over time we could build huge ships with massive walls that we could send to Mars. No problems with radiation.
But of course the only reason we went to the Moon was to beat the Soviets, and the reason we will go to Mars is to beat the Chinese. This is not a plan. This is just another episode of America's Got Talent.
Hopefully, that is obvious to everyone.
I have always supported the robotic exploration of space, which includes space telescopes, orbiters, landers, fly-bys, sample returns, and Earth satellites.
Also, as long as your HUMAN space explorations and settlements are funded by private investments or private philanthropy, I say, “Explore and settle to your heart's content.”
However, when space investors and philanthropists demand that taxpayers help fund HUMAN adventures, I say “no,” unless there is a clear path to commercial profits.
Besides space tourism, which has already started, there are no commercially viable business plans for space, except maybe for Helium-3, but, since no one has ever built a Helium-3 reactor, who knows?
Re: Barter and trade in 10,000 BC
There was very little.
A couple million people were spread out across Africa, Europe, and Asia. There were no roads, no farming, no domesticated animals (except hunting and guard dogs), no boats, and no wheels. Most people spent their entire lives within 100 miles of their birthplace, because everything they needed to survive was readily at hand - or else they died.
In sharp contrast, small numbers of space settlers will be spread out over hundreds of millions of miles. And, they will be in perpetual need of highly sophisticated equipment - just to sustain their lives. Who is going to make that equipment, except people on Earth? And who is going to pay for that life sustaining equipment, besides people on Earth?
Re: “James Clerk Maxwell in 1859”
I know Maxwell devised all the seminal equations for electromagnetism.
I have no idea what Maxwell did in 1859 to solve the speed of light problem in space travel.
I think it is quite possible that the future of human beings will look much like Star Wars and Star Trek.
On the other hand, I think that future is thousands, and probably tens of thousands, of years away.
Maxwell’s original field equations described thing like free energy, stepping from one point to anther anywhere. Among many other things which where tossed aside by Oliver Heaviside except for 4 (of the 200 original equations) which Heaviside changed to vector equations - from those four everything we know about the electromagnetic spectrum descended - both Einstein and Tesla were heavily influenced by Maxwell - Tesla even try to engineer broadcast power Maxwell described.
There are new discoveries which point to an extensive, worldwide, sophisticated civilization prior to 10,000 BC. Gobekli Tepe was built then by someone, then deliberately buried - recent excavations are only partially done on the entire site. Very sophisticated megalithic site. There was likely worldwide trade prior to the comet strike which ended the Younger Dryas. A lot has changed in the origins and history of humanity in the past two decades and the new discoveries seem to be accelerating.
Days? Try minutes -- as I clearly stated, the Apollo missions' trip through the Van Allen Belts took minutes, and that's when they were in the most concentrated areas of radiation.
Nuclear propulsion is being studied by SpaceX, supposedly per Gwynne Shotwell, but it has the same limitations that it has always had. It's only good for shuttling things from orbit around one planet to orbit around another, requiring bigtime chemical propulsion boosters to get it to orbit in the first place, because the weight of the system offsets any potential increase in specifiic impulse. The only advantage if may offer will be to push probes to other star systems, yet it would still take a few lifetimes to accomplish the journey.
The argument that use of nuke prop would reduce consumables is found everywhere, but it is spurious, because that's such a tiny amount of the required payload. Cargo (such as habitats, greenhouses, and such) in larger quantity doesn't need to be sent with (or wait to be sent with) human passengers, nor does it have to get there on a strict timetable, or even wait for the favorable position of the two planets.
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