I have a new post up at Air & Space discussing the various simulations undertaken to prepare for future human space missions. Comment here if desired.
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It’s all very interesting, and good reference to submarine crews as any human planetary mission will involve crew interdependent of each other. Regarding simulations at Arctic base camps, what about those living at Antarctica during winter months? I remember a magazine article in 1970s that said those who endure and cope the best are slobs. Neatnicks tend to get stressed out the most.
I found this sentence insightful, “Most Apollo astronauts had the benefit of military experience and thus understood factors important for their survival, such as preparation, teamwork and working under pressure within a chain of command.” These days fighter/test pilot qualifications are probably not as important for long duration missions but discipline and teamwork are still valued for obvious reasons. I see you pointed out the issues of radiation, and that might be the show-stopper for any mission outside our magnetosphere.
However until we get hardware that can take us someplace (no, not another Apollo 8 redux with Orion) then all of this is moot.
In meantime still keep up advocating the Moon, i.e. “Another Way to Land on the Moon.” Hey, how about a lunar rover with high quality cameras like they have on Mars to check out the Apollo sites, see what solar radiation has done to the hardware. Or visit some of the third stage impact sites to see what and how much the Sun as affected soil exposed in only 45 years.
how about a lunar rover with high quality cameras like they have on Mars to check out the Apollo sites, see what solar radiation has done to the hardware. Or visit some of the third stage impact sites to see what and how much the Sun as affected soil exposed in only 45 years.
That would be valuable data. However, we do have a problem — NASA legal guidelines prohibit anyone approaching the Apollo sites closer than a couple of kilometers to land and several hundred meters to rove. Whether they would prosecute violators is unknown.
Interestingly, an international mission (not subject to NASA strictures) could do whatever they wanted to. So while the hands of U.S. citizens are tied, those of other nations are not.
Mars probably wont kill you but getting there and back prabably will.
Taken in whole, i.e., considering all the major biomedical challenges involved, there about 30 or so, no ‘active’ human can do Mars based on todays propulsive technology. After 4 billion years of bio-logical evolution the universal and ubiquitous strategy in nature for dealing with overwhelmingly long, hard and unpredictable times is hands-down hibernation. More on that in a sec … there’s actually hope
Speaking from direct, first-hand experience literally risking life 3-4 times a weeks for several hours a day and well over a decade, and more recently dealing with extreme, self-imposed isolation and confinement in really shitty and unstimulating wilderness further reinforces my belief in a zero doability factor on this front, i.e., in this way. Harder guys used to solitary confinement (forced incarceration) might make it, but they would be forever changed and for the worse; they’re probably already too far gone to be recruited. Any busy-body careerist (e.g., an astronaut) has absolutely, I repeat, absolutely NO chance. Mars may be ‘The Martian’, but going to Mars (return would definitely not be. Whoever is running NASA’s bic-picture human deep-space survival front is clearly and completely clueless, a romantic dreamer, a weekend camper and/or, worse, a self-interested parasitic careerist running a jobs program. Sorry, I’m not the type to mince words and I can see bull from a mile away.
Ironically, early NASA went down the hibernation road in the 50s, the early guys were smart doers, and the critter data for collapsing most of these problems was outright impressive, even against hard radiation and hypokinesia. But the metabolic switch and trigger proved an elusive enigma. As a result the human program went piecemeal all over the shop, wasting countless hundreds of millions (billions?) since then. ‘Moon focus’ also made for hibernation or multi-day torpor (almost) completely pointless; it’s also hardly action hero stuff. This is where NASA went and is still going astray. As such NASA Mars is completely hallucinogenic; even ESA has figured this out. Needless to say, the half-baked mimic involving ‘therapeutic’ hypothermia as a substitute for hibernation, as put forward by SpaceWorks, is an iatrogenic no-hoper and complete fantasy.
Where are we at with it now, seriously? We’ve got several kind of recently discovered primates who real deal hibernate, at least one who does it for as long as 7 months straight, i.e., lights-out for more than half the year. We’ve also got some first-in-human (not inhuman!) experimental data that we generated using a biomimetic model of animal (mammal) hibernation indicating we can probably do this based on some impressive critter-like off-the-chart vitals; we haven’t tested to see how low and long we can sustain it but we’ve got a smile on our face so far. The data was independently measured because we’re highly skeptical of any data, especially our own. The human data is also supported by 30s and 40s data from several hardcore physiologists looking at Australian desert aborigines who could overnight lower MET below the purported basal rate in a way similar to some marsupials sharing this inhospital environment. I’d post some initial data but Paul’s blog doesn’t allow it as far as I can tell.
By the way, really appreciate Paul’s effort on this blog. I’m new to it. I know essentially nothing about the moon, but find the blogs very insightful and appreciate the ‘call it like it is’ approach.
Thanks for another excellent article Dr. Spudis.
IMO, the primary purpose for sending humans into space and to the surfaces of other worlds is to find out if our species can live and reproduce beyond our planet of evolutionary origin– without significant deleterious effects to our health and reproduction. The psychological effects of being away from the Earth’s surface for a few years is also something that NASA needs to learn about before sending astronauts on interplanetary missions beyond cis-lunar space.
This is why I strongly believe that during the 2020’s, a simple human outpost should be included at any water and propellant producing outpost on the lunar surface in addition to a rotating artificial gravity producing outpost at one of the Earth-Moon Lagrange points (L3, L4, and L5 would have substantially lower station keeping requirements than L1 and L2).
By the late 2020’s, several male and female NASA astronauts should be sent away from the Earth’s surface for at least three years or more, spending time at both the lunar outpost and the rotating Lagrange point outpost.
An SLS derived rotating artificial gravity outpost could produce about 0.5g of simulated gravity (a higher gravity than the Moon and Mars) while astronauts would experience 0.16g on the lunar surface.
In theory, frequent exercising such as sprinting on treadmills and heavy weightlifting should mitigate or even eliminate the deleterious effects of a low gravity environment. A cis-lunar test program on NASA astronauts could quickly tell us if this theory is true.
Marcel
Judging from the latest report I’ve read it’s looking like no amount of high intensity exercise of any kind is going to be able to mitigate the down-sides of incessant near zero gravity. As any high end athlete will tell you, remaining a couch potato between conditioning bouts doesn’t work too well even on Earth, let alone in space. That aside, too much exercise opens you up to further immune system problems of which there are already plenty up there already. Then you’d be consuming so many calories and generating so much waste it would be a real technological strain.
Part of the big problem is that so many physiologic systems are affected and interdependent on one another that it’s a near-impossible juggling act. The human problem isn’t merely daunting, on it’s present trajectory it’s intractable. This has all the hallmarks of being a NASA jobs program, like their heavy lift rocket system.
Interestingly, last I heard JAXA was going to send up some hibernating critters to see if they could handle the muscular atrophy, but the only critters who can mitigate atrophy really well are ones that don’t need to arouse in hibernation. To do that they’d need to be of a certain size, i.e., biggish. A hamster or a squirrel wont cut it because as soon as the lights come on they be subject to hypogravity and probably lose the mileage gains of hibernation. I suppose you could send a hibernating lemur (a primate), but many of these are already endangered so it’s ethically unjustifiable most probably. A bear would be the next to ideal choice, but for obvious reasons we can’t do that, which means we’re kind of stuck unless humans can be induced to hibernate.
Exercise does help to reduce some of the deleterious effects of a microgravity environment. But a microgravity environment, of course, is not the same as a low gravity environment.
It takes around 0.1 g for humans to have enough traction to be able to walk on a planetary surface. A one sixth lunar gravity, therefore, is not an insignificant amount of gravity. But whether a 1/6 gravity is significantly harmful to the human body is unknown since we have no experience deploying humans for months or years at a time on the lunar surface.
Bone Loss and Human Adaptation to Lunar Gravity
http://www.nss.org/settlement/moon/library/LB2-612-AdaptationToLunarGravity.pdf
Living and Reproducing on Low Gravity Worlds
http://newpapyrusmagazine.blogspot.com/2014/09/living-and-reproducing-on-low-gravity.html
Marcel
Gary Hudson also addresses the problem of low gravity:
Gravity is a Massive Problem
Thanks for that video. I didn’t know it was available.
Several issues:
– When do we really need to know the AG Rx for adult, childhood, & fetal health? No time soon. We don’t need to know the gravity Rx for the moon initially because it is only three days away. Probably not for the initial Mars missions either.
– We could go to the moon and then conduct AG experiments there with an intermediate-arm centrifuge which is what we would use eventually on planetary surfaces.
– O’Neilians don’t ever need to know the gravity Rx.
– When going to Mars, why not tether & spin up interplanetary craft to 1 gee. The mass penalty is modest.
– Could cheaper orbital AG experiments be done with inflatable, tethered, spun-up habs?
Thanks for that. Interesting links. Unedited, top of my head, it may perhaps be possible to very roughly infer the shape of the hypogravity-biological effect curve by extrapolating to incrementally higher Gs, since we can do that, and then looking back to near zero G (ISS data) via the 1G point (Earth data).
I would agree with you on that Doug. Further, exploration for exploration’s sake is a luxury that we cannot afford, but we mught if underpinned by a rational development of capabilities. In short, because space is expensive it really needs to use a DARPA-like innovation model, which involves fundamental science understanding with cross-cutting applications, i.e., operation in the Pasteur quadrant; the Bohr quadrant is mere scientific curiosity, the Edison quadrant is mere application with no fundamental understanding.
DougSpace mentioned about 1-g tether for spacecraft, they did a tether experiment on a Gemini mission with the Agena but didn’t spin up to 1-g. In terms of centrifuge as portrayed in sci-fi movies, I’ve seen articles discussing where that is not practical unless diameter is very large (hundreds of feet) otherwise it will feel like the floor is slipping below your feet (lower body moving significantly faster than upper body).
Behind the Visitors Center by main gate of Ames Research Center is leftover mockup of a module to showcase a centrifuge that was planned for ISS. Ironically this science package was cut to provide funding to complete the space station.
Actually, the real limit for simulated gravity is the rotation rate due to motion sickness.
Based on earth based studies (done in the 1960’s) it has been assumed that a rotation rate of 1 to 2 RPM was the limit.
The level of simulated gravity increases with the square of the RPM rate.
That is:
(1) If you assume 1 RPM and want 1 G you get a diameter of 5,874 ft.
(2) If you assume 2 RPM and want 1 G you get a diameter of 1,449 ft.
Several years ago (at a Human Factors conference) I had the good luck to get to talk at length with Dr. Joseph Kerwin (medical Doctor and Skylab astronaut). Based on his Skylab experience and subsequent research he was convinced that the rotation rate could go as high as 5 RPM.
If you assume 5 RPM and want 1 G you get a diameter of 235 ft.
It is doubtful you would want to go much beyond that as the level of simulated gravity would very enough over of the range a crewmember’s height to make standing up suddenly a disconcerting experience.
“I’ve seen articles discussing where that is not practical unless diameter is very large (hundreds of feet)-”
Tethers are the most practical of all artificial gravity systems and due to that very fact; a mile long tether bearing several thousand tons only weighs about 8 tons or so. Why are you writing about it as if it is “impractical”?
“An SLS derived rotating artificial gravity outpost could produce about 0.5g of simulated gravity-”
“In theory” a couple SLS worshops attached to each other with a tether system could produce one gravity. Why in the name of evolution and human physiology would you want to cut what is healthy in half?
Training for specific EVA tasks as described in the Air & Space Article are valuable, not only for crew proficiency; but identifying tasks and required new tools.
Similar activity was done in the Neutral Buoyancy Facility (NBF) for Assembly/Maintenance on the ISS.
Before Constellation Systems was cancelled it was intended to use the NBF to do similar evaluations for Lunar Surface Activity.
Not too sure about use of remote location as analog for actually being in space (as noted the environment is very different).
In the past Astronauts have done time in underwater labs to get familiar in (what I guess could be called) a social sense with what it would be like to do a tour on a space station/lunar base.
I would like to see a new Moon-Mars Analogue Base (MMAB) which would have its focus be on development rather than exploration. It would be large enough to house a crew of eight and would have an indoor greenhouse and centrifuge to make the base increasingly Earth-independent. It would be a 36 meter diameter inflatable and 2.5 meters tall — like a large pancake. Telerobotically covered with regolith, the crew could stay for extended periods thereby reducing crew rotation costs.
This analogue base could be the site whereby life-support equipment, greenhouse development, organic & inorganic chemistry, metallurgy & machining, animal AG, and telerobot repair protocols could be developed.
Would I be correct in assuming long duration stays on the lunar surface would provide a simulation of the radiation enviroment that is encountered to and from Mars?
At the very least, it exposes astronauts to the hazards of fine dust.
Haven’t we figured out what good shielding materials exist?
I’ve heard of using several inches of plastics or “water tiles” (like bags of water lining the hull).
Yet another reason to access lunar water.
Would I be correct in assuming long duration stays on the lunar surface would provide a simulation of the radiation environment that is encountered to and from Mars?
Pretty much, except to the extent that the Moon’s orbit takes it into and out of the Earth’s geomagnetic tail, which affects some charged particle intensities (not galactic cosmic rays, though). But one difference is that on the Moon, you can shield yourself to whatever extent necessary. On a flight to Mars, you take the radiation dose that your limited shielding mass permits.
What is needed in my view is a sea change, a paradigm shift, in the way the radiation issue is addressed. It is fundamentally about providing a near-sea-level radiation environment and one gravity. Start with that instead of going bassackwards and playing the no-win game of “managing” exposure and debilitation.
The Moon is the key due to it’s location outside the magnetosphere (allowing nuclear missions) and it’s ice-as-water-shielding resources.
As for living permanently on any natural body besides Earth this is another no-win game that was addressed back in the 70’s by Gerard K. O’Neill. He concluded that only artificial hollow spinning moons were appropriate for space colonization and the science and physics supporting that conclusion have not changed. In fact, the ice on the Moon only supports this path.
One advantage of shielding interplanetary transfer habitats with lunar water is that you can dump the heavy water mass shielding prior to the final trajectory burns to enter Mars orbit– substantially reducing the amount of propellant required to reach Mars from cis-lunar space.
Once in orbit around Mars, water shielding can be immediately pumped back into habitat modules from pre-deployed water depots in orbit around Mars which will also use water originating from the lunar surface.
Eventually, only hydrogen may be needed to be shipped from the Moon to Mars orbit for providing propellant and water shielding for interplanetary vehicles returning from Mars to cis-lunar space. The oxygen component could be manufactured from the regolith of Deimos and Phobos, if water deep beneath the regolith of the martian moons are too difficult to economically access.
Marcel
“-interplanetary transfer habitats-”
It is called a spaceship. A true spaceship capable of multi-year missions to the outer solar system would likely have several thousand tons of water shielding, a several thousand foot long tether system (when not under power), and a soft or hard or hybrid nuclear pulse propulsion system. The soft version being a Medusa-type “spinnaker” and the hard version a several thousand ton alloy disc. This is the basic shielded rotating construct necessary for interplanetary human missions and it will necessarily be assembled, tested, and launched from the vicinity and/or surface of the Moon.
“-pre-deployed water depots-”
Since the water shield will also be the grow medium for a closed cycle life support system just dumping it into space does not sound practical. The organisms use to provide years of breathable air and sustenance might be transferred and concentrated temporarily. Traveling to low gravity icy bodies a percentage of the shield (the outer layer) might be expended as propellant for the nuclear pulse system but only when ISRU to replace that shielding could be effected almost immediately.
“-Eventually, only hydrogen may be needed to be shipped from the Moon to Mars orbit-”
Again, Mars is a gimmick, a P.R. hook to garner support from emoting clueless sci-fi fans. It is portrayed as “just close enough” when it is not.That space enthusiasts jump on the Mars bandwagon is due to a lack of knowledge. Colonization is best accomplished with habitats in the vicinity of Earth using lunar construction materials. Mars is not a good candidate for a pure exploration mission- the ocean moons of the gas giants are far better destinations. Why? Because if you have the necessary true spaceships to go to Mars then bypassing that rock becomes obvious.
The transfer-depot-Mars jargon displays everything wrong with the present popular culture vision of space travel.
I would add that “it will necessarily be assembled, tested, and launched from the vicinity and/or surface of the Moon” is the key point that all space advocates should be focused on. The ice on the Moon is the critical enabling resource and this has been almost completely ignored for the last 5 years- since the work of Dr. Spudis played the major part in revealing it.
LEO and Mars are dead ends and incredibly wasteful distractions preventing any progress. A billionaire’s hobby rocket project currently seems to be the carnival sideshow captivating the public. As long as this farce called NewSpace keeps crippling any organized state sponsored public works project no new space age can begin. Human beings have not left the gravity field of Earth since 1972 and this measure of success and failure cannot be techno-babbled away.
When it is realized a Space Shuttle launche did not turn out to be much more expensive than a Saturn V launch then 30 years and 130 shuttle flights can be seen as a sad tragicomic lesson in poor political leadership. The next president is the last chance in my lifetime for a real space program. The election is less than a year away and very little is being done by space advocates. We are hopelessly divided and so there is little hope.
https://en.wikipedia.org/wiki/Saturn_V#/media/File:Saturn_V_launches.jpg
“When it is realized a Space Shuttle launche did not turn out to be much more expensive than a Saturn V launch then 30 years and 130 shuttle flights can be seen as a sad tragicomic lesson in poor political leadership.”
I get so upset sometimes a can’t even spellcheck; When it is realized a Saturn V launch did not turn out to be much more expensive than a Space Shuttle launch then……….
My point being if we had just kept launching Saturn V’s (and more efficient iterations of that vehicle) and kept exploring the Moon- even with robots initially- then we would would be up to a couple hundred missions by now. The ice and lava tubes would have been mapped, human missions resumed, and a permanent lunar base now in operation for the same money.
Instead of the do-everything-pay-for-itself-cargo-bay-of-dreams and the deteriorating space station to nowhere.
This kind of “what if” hindsight is extremely important. If we do not learn from our mistakes we are doomed to repeat them. The hobby rocket is essentially just a cheaper nastier version of the same concept that has kept the U.S. trapped in LEO for almost half a century. There is no cheap.
(1) If you assume 1 RPM and want 1 G you get a diameter of 5,874 ft.
(2) If you assume 2 RPM and want 1 G you get a diameter of 1,449 ft.
” Based on his Skylab experience and subsequent research he was convinced that the rotation rate could go as high as 5 RPM. ”
“If you assume 5 RPM and want 1 G you get a diameter of 235 ft.”
Thanks Joe- really excellent info. When this is applied to various concepts a fascinating continuum of constructs appear. The classic von Braun wheel illustrations are in the 235 foot range. Unfortunately, though it is shocking to most space enthusiasts, bigger will most likely be required.
With massive water shielding and an efficient nuclear pulse propulsion plate the torus could fit within the diameter and spin either independently or with 1,,449 ft. plate. Such a monster alloy disc would have to be manufactured on the Moon, perhaps from lunar titanium. However, a tether system makes smaller “true” spaceships possible by “splitting the ship.”
The 1 RPM mile plus in diameter is the classic spinning Bernal sphere envisioned by Gerard K. O’Neil (constructed on lunar material fired by a rail gun into space and gathered and processed at a Lagrange construction site. Walking on the inner surface equator it would take about an hour to arrive back at the starting point.
I would add that with a concept I call “kicking the ball” these miles-in-diameter spheres made of lunar ore and forged and formed using solar mirrors could conceivably become Starships.
Twenty thousand or so H-bombs could kick such a ball to a small percentage of the speed of light and send it on its way to another solar system. No real technical obstacles to doing this (as Freeman Dyson pointed out nearly half a century ago).
Of course condemning many generations of human beings to living inside such a sphere their whole lives does not seem very practical. So I would say there is only one technology missing; freezing people. Unlike warp drive and transporters it is not such a difficult advance to imagine. The main problem being preventing ice crystal from forming at a microscopic level and disrupting cellular walls. A form of this is already being done in the food storage industry.
http://www.forbes.com/forbes/2008/0602/076.html
And of course, actually being able to freeze people is the ultimate disruptive technology that would change the human condition far beyond simple star travel. Freezing our loved ones and ourselves until a cure is found for whatever is killing us (most often old age) would become a basic human right and drag civilization kicking and screaming into the larger universe.
Suspending metabolism is largely a (body) size related problem. The temperature drop than can be tolerated is dependent on the metabolic scope available. There is less metabolic scope the larger the ‘animal’. If you were bacteria you could last a very, very long time. Some arctic insects and amphibians can tolerate super-cooling. Actually, even an arctic ground squirrel can dip below the freezing point, but any mishandling (e.g., shaking) is likely to result in crystal seeding and frostbite. The point, calories are still ‘consumed’ and you can’t remain in a metabolic holding pattern indefinitely. There’s also an upper limit to how much fattening up you can handle (autophagy). Fattening up and delaying hibernation results in premature death rather than prolongation of longevity. For mammals, and small ones at that (pygmy possum), the endurance record is no more than about 12 months. Scaling to an adult bear weighing 150-200 kg (i.e., some, correction, many human would give you around 7-8 months; maybe 9 months at tops.
“-an arctic ground squirrel can dip below the freezing point, but any mishandling (e.g., shaking) is likely to result in crystal seeding and frostbite. The point, calories are still ‘consumed’ and you can’t remain in a metabolic holding pattern indefinitely.”
A cryogenic temperature means no calories are consumed and the “holding pattern”, if not for radiation damage, would be indefinite. There are no numbers on this yet, but even a completely shielded frozen human body would still suffer damage from decaying isotopes already in the body and would have to be revived periodically to allow for a month-long natural DNA repair period. How grievous the accumulated damage would be if left unchecked is unknown. What the optimum repair frequency would be, whether 50 years or a thousand years, is unknown.
I would add that “hibernating” for 9 months on space missions may make sense in some fashion but I would want nothing to do with it. Since massive shielding is still necessary to prevent over-exposure to radiation and the most powerful nuclear propulsion system available is required to push this massive shield, the savings might not be so impressive. Adding payload by eliminating living space/artificial gravity/consumables with hibernation would be a comparatively small gain due to the thousands of tons of shielding in my view.
Your assuming that you you’d have to rely on passive shielding, but some (not insignificant) headway has been made involving active shielding by an English group more recently (Cavendish Lab I think).
An often overlooked fact is that passive (material) shielding is not a radiation all-comers solve it all. Actually, it aggravates the HZE GCR problem, i.e., less the shielding is really and impractically thick, even for ‘water tiles’. NASA knows this quite well and remains stumped, as can be gleamed from their Mars GCR open-source challenge.
You’d have to be a sea-monkey (brine shrimp) or maybe a tardigrade to cope with a direct radiation hit and survive; these critters rely on extreme dehydrationq (anhydrobiosis) for coping with low-level radiolysis and, at least in the case of the shrimps, they have DNA repair molecules and proteins that lack a fixed structure. Even despite surviving heavy GCR hits, the Apollo 16/17 Biostack I/II experiments showed deformities in the survivors. By the way, these critters can also tolerate cryo temperatures. The only thing that was found essentially insensitive to HZE radiation was bacteria (and plant spores ?)
I’m all for radical perspective shifting or zero to one thinking but I’m also a pragmatist. We’re now starting to talk about sci-fi transhumanism beyond the realms of reasoning or even blue-skies innovation, i.e., it would require multiple major biotechnological miracles to pull off. Quite simply, we’re talking about a challenge with a very near zero doability factor.
PS: one way or the other, shielding is needed. Either way, it will be ‘massive’. If that’s the case, you may as well have active shielding since it’s more broad-spectrum … until it fails.
PPS: By the way, the Cavendish group also found regions of low(er) radiation on the moon which I think they dubbed mini magneto-shields or something of that nature. But I think you lunar guys would know more about that than me.
“We’re now starting to talk about sci-fi transhumanism beyond the realms of reasoning or even blue-skies innovation,-”
Well, you are talking about it……I am talking about radiation. I was NOT assuming anything except the fact that the only way to stop the heavy nuclei component of galactic cosmic radiation is mass and distance- “active shielding” does not work. I am not a sea monkey or a tardigrade and “impractically thick” may be the NASA position but it is not reality.
“-it aggravates the HZE GCR problem, i.e., less the shielding is really and impractically thick, even for ‘water tiles’. NASA knows this quite well and remains stumped,-”
I do not want to get into a long drawn out debate about shielding…..yet again.
NASA may be “stumped” but the guaranteed solution was explained to the general public several years ago by a recognized authority on space radiation. Eugene Parker specifies 15 feet and 500 tons of water to completely shield a small capsule.
I call this the Parker/Dyson/Spudis effect.
Parker explained the problem and detailed the solution, Freeman Dyson long before this provided the means to move the required shield around the solar system (nuclear pulse propulsion) and the work of Paul Spudis revealed the site to acquire the shielding and light off nuclear devices: the lunar poles.
That NASA does not seem to have anyone that can put two and two together and effect a solution is not my problem.