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Forget Space Travel, It's Just a Dream
An anonymous reader writes "The clash of two titans — physics and chemistry — are major barriers to human space travel to Mars and beyond, and may well make it impossible ... at least with current technologies."
If it is impossible in the real world, why not solve it with math?
a space elevator aka beanstalk aka orbital tower.
Once you get out of earths atmosphere and gravity well, you're halfway to anywhere (in the solar system)
Most people have no real appreciation of the scale involved in psace travel. As daunting as our own solar system is, even that pales in comparison to the scales involved in traveling to other solar systems. Currently it takes us about 9 years for a probe to reach Pluto. When I ask people to guess how long it would take that same probe to reach the nearest solar system (a mere 4.2 light years away), people's estimates are usually comically far off.
120,000 years is the correct answer. Most people guess between 100-1000. That's why people think it is plausible for mankind to colonize space. They don't appreciate the scale we're talking about.
SJW: Someone who has run out of real oppression, and has to fake it.
...But that's the thing about current technologies: They inevitably insist on becoming obsolete technologies.
How can I believe you when you tell me what I don't want to hear?
So basically something we haven't invented the technology for is impossible until the technology is invented.
I'm so shocked.
ADVENTURERS! - ANTIHERO FOR HIRE - CARDMASTER CONFLICT
wow really? Even a monkey could have figured that out.
did you forget to take your meds?
There is only so much power you can get out of a locomotive, and it's never gonna make one fly in the sky due to the considerable weight of a steam engine.
Great summary. All of one sentence that tells us nothing, not even what the source is. I really don't understand what Slashdot wants for a submission so I've mostly stopped bothering.
Plenty of interstellar ship concepts propose nuclear power and are therefore outside the "titanic" power of mere chemistry.
An Orion engine could get you to the stars in 40 years, Mars in a few weeks. A solar sail can accelerate you almost up to the speed of light and travel to the ends of the universe. It's politics and economics that are major barriers to space travel, not physics and chemistry.
Remember, any kind of space travel was thought impossible at one time ... until the multi-stage rocket was invented. We need more creative thinking and less of this overly pessimistic nay-saying.
What would we need to find out there? Why would anyone want to be there?
Because at some point the sun will turn into a red giant and swallow the earth whole. This will obliterate humanity and every single thing we've ever done. We will be completely and irreversibility erased from the universe.
A lot of people find that thought rather uncomfortable.
According to Physics and Chemistry self-propelled chariots are impossible STOP self-propelled flying vehicles are a fool's errand STOP Internet is that little net inside some pieces of underwear STOP.
Premise: You cannot go into deep space because chemical rockets have insufficient energy to get you there.
Recommendation: Therefore you should only send people into space one way.
Real purpose of article: For the Author to brag that he is wealthy enough to book a flight on Virgin Galactic.
OK, OK I concede that stuff like flue powder, aparating and portals seem improbable, just to show that I am not unreasonable, and am considering only proven viable technologies.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
That article is a joke. It doesn't even take into consideration very public recent development like http://www.fastcompany.com/1744745/russia-us-plan-a-nuclear-powered-space-rocket-should-we-worry
Plus Russia announced it created a nuclear reactor that was capable of being transported and used in a rocket some months ago. Plus the sun is an infinite source of energy when you are in space, which should make whatever fuel you are going to use last longer.
Its hard to tell because the article contains no facts or assumptions, but I think it is working on the assumption that the Mars space craft and all fuel will have to be lifted from the earth in one go. If we assemble the craft in earth orbit then fuel it in multiple trips the energy requirements to get it to Mars orbit will be much lower. At that point it can again use a "lander" vehicle to take the astronauts and equipment to the surface, a lot of which can be left behind for the return trip (as was done with the moonshots).
I mean, really, in 1969 we magically had all the tech to get to the Moon and back, it's not like we had to invent anything. /sarcasm
People get paid to write this crap?
--
BMO
NOM NOM, Nothing wakes you up in the morning, like crushing the hope of science dreamers everywhere.
To quote Einstein: "Whoever undertakes to set himself up as judge in the field of truth and knowledge is shipwrecked by the laughter of the Gods."
Of all objects, the planets are those which appear to us under the least varied aspect. We see how we may determine their forms, their distances, their bulk, and their motions, but we can never known anything of their chemical or mineralogical structure; and, much less, that of organized beings living on their surface
Said by Comte in 1842. There is a difference between unknown and unknowable.
.
Isn't that what dreams are about? Inventing new technologies to do in the future what is not possible now?
Asteroid mining?
The quick answer (which I'm sure many posters have already said) is don't involve chemistry; use nuclear engines, or ion engines or solar sails or magnetic balloons. There is a lot more energy (million fold) in nuclear bonds that you can get from fission reactors or by using the fusion furnace at the center of our solar system.
That said, I haven't really heard of good answers to long time LIVING (not just survival) outside of the earth's magnetic field/shield and without one-gee acceleration keeping our bodies reasonably fit. Want to COLONIZE Mars and not just go there for a flags and footprints mission? Well we have no idea if the 1/3 G gravity will keep the astronaut's bones from becoming brittle. Who knows if women can give birth to healthy infants in such an environment or even if we can grow crops there! (I really thought they shouldn't have cancelled the centrifuge that was to be a part of the ISS. Hopefully, if the Falcon 9 works out, it'll be cheap enough to add it later).
I'm actually a little more optimistic about the long term ability of humanity to spread throughout the cosmos. In just a few decades, hopefully we'll know enough about our biology to really tinker with it. Getting rid of susceptibility to low gravity is a given of course but how about a little radiation hardening? (Some organisms can tolerate millions of times as much radiation as we can). Perhaps later we could learn to deal with decompression sicknesses (like marine mammals) so spacesuit design could become a lot simpler. Maybe we could learn the tricks of hibernation from bears and squirrels so long space flights wouldn't consume so many resources (and be so boring!).
We might end up not quite the same as homo sapiens. Call it man plus. (For INTERSTELLAR travel, we'll need some pretty spectacular physics or some pretty radical reengineering of ourselves. How 'bout brains in boxes? Or better yet, just software running on commodity hardware?).
But it might take awhile.
Please let us moderate the summaries. Bad summary of a bad article.
TAANSTAFL
Robert A. Heinlein
Everything costs. Even if you do away with all of the world's currency, things will still cost. You will merely be stating the costs in another manner, ie, "manhours", or "credits", or - whatever.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
I might be missing something here, but wouldn't that be lethal? 1 Sv results in mild radiation poisoning, and 8 is death no matter what. You'd be sick in 4 hours and dead in 32.
Sent from my CR-48
There are fully contained nuclear rockets. They are called gas core nuclear rockets, or nuclear light bulbs. The reaction uses uranium hexafluoride gas, spun into a vortex. This vortex is contained within a sealed, quartz walled chamber. The reaction produces a lot of UV radiation. Quartz is transparent to the UV radiation, so it escapes the container. Propellant is run past the quartz wall and absorbs the UV radiation, and heats up, expanding in the process. Voila, a nuclear rocket with no radioactive exhaust.
When our name is on the back of your car, we're behind you all the way!
The author of the article needs to read "Not final!" a short story by Isaac Asimov
http://en.wikipedia.org/wiki/Not_Final
...because chemistry is just applied physics.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
I'd like to remind people that scientists as recently as the 1940's said that flight faster than the speed of sound was impossible. That flight beyond the atmosphere was impossible.
Before that, they said that flight was impossible, and anyone travelling faster than 35mph would kill the occupant.
Just ask any top-fuel dragster jockey about what's impossible. Engineers were swearing up and down that they had reached the limit of what internal combustion engines could do in the 60's, but the guys building the dragsters kept proving them wrong.
I'm sure as far back as cavemen, there was a 'scientist' that was positive that man-made fire was impossible.
The point is: Sooner or later, anyone that says that anything is impossible is proven wrong. Don't be a naysayer, be that someone that changes the world. Find the way to achieve the impossible.
If telephones are outlawed, then only outlaws will have telephones.
Your figures are wrong. If any of it were true no astronaut would live through a mission. Your own source even notes "Actual radiation dose measurements of Apollo crews measured by onboard dosimetry were, on average, 12 mSv." That's 0.12 Sv... relatively high vs. average everyday life but far from 'tens of Sv/hr' which would kill people.
I support the Slashcott and will not be reading or commenting from 2/10/14 to 2/17/14. Beta is steaming pile of dog shit
submarines and aircraft carriers?
Got to space in Early 60's
Got to the moon in the late 60's
Both of these were single hop's, a trip to Mars is likely to be a staged journey, build the craft in orbit, or on the Moon, and use fuel from Space, the article assumes that the only possible way is a single hop from the earth to Mars (or further) taking everything, fuel, supplies with you.... This is impractical, but not impossible
Making predictions about future technology is foolish at best .... go and speak to anyone in the 1950's about a compter with 6,000 logic gates, contained within 40 square mm they would say that was against the laws of physics and chemistry ... but the Intel 8800 had this in 1974
Puteulanus fenestra mortis
Reading Cosmos for science is like reading the National Enquirer for news. TFA presents a false dichotomy: it takes lots of energy to move stuff between space and the surface of the earth. Therefore space travel is impractical. Whats wrong with this?
Space travel takes a huge initial investment to establish a real infrastructure, including mining and manufacturing. After that, it's all gravy.
Enjoy life! This is not a dress rehearsal.
TANSTAAFL!
There Ain't No Such Thing As A Free Lunch!
Yes, lots of things are possible with current levels of technology. That's why we invent new technology.
Just a week ago I've seen the report on talks about cooperation between VASIMR's Ad Astra Rocket Company and some branch of Rosaviacosmos developing the Russian megawatt class space-based nuclear reactor. If they succeed, it will be your next level space drive.
I'm pretty sure "carry our own fuel" is fine - but you plan for fuel boosts along the way like a giant video game. It's all about staging. The docking tech is a little weird but it has to be "relatively easy" to make the docking interface. Then you launch up a bunch of fuel cargo ships and park them all in orbit. Once you think you have enough, you string them all out in a row at intervals. Then you just 1-UP your way to Mars.
Bonuses for multiplexing the types of energy - part solar, part stored fuel, debris gathering maybe for a ballast dump twice per route to save fuel on a course correction.
The bigger thing is we absolutely have to quit squabbling among ourselves and get a grip because it will take the resources of at least two nations to pull it off.
My first Journal Entry ever, in 8 years! http://slashdot.org/journal/365947/aphelion-scifi-fantasy-horror-poetry-webzine
http://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm
Ultimately, you can bet future won't be as imagined in works of popular fiction - because you must remember that's what scifi is. Grandiose, fabulous, "awesome" style of exploration depicted in those - that's catering to audiences which would be uncomfortable with anything too dissimilar from Earthy experiences; and coincidentally making the work of writers helluva easier. A sign of... limited imagination (how many people remember that we can already transport people while miniaturized and in deep hibernation? Heck, give me one medium launcher + additional few dozen million bucks, and I can transport at least a thousand living / viable humans to pretty much anywhere in our system), afraid to face what the wild realities of existing universe.
And ultimately, people will remain upset how space travel will most likely remain different from earthly experiences
BTW, how is that building of ships' hulls ignoring Archimedes' principle going along? It's over 2k years old, surely we should be able to ignore it by now, eh?
One that hath name thou can not otter
http://en.wikipedia.org/wiki/Mars_Direct
http://en.wikipedia.org/wiki/Mars_for_Less
Or try this, if you are more partial to video.
And then... there's the colonization option.
Best part is, no unobtainium needed. Everything is based on current, tried technologies already in use.
Mit der Dummheit kämpfen Götter selbst vergebens
We have known since the 1930s that the energy bounding atoms together is nothing compared to the energy bounding the atom nucleus together. In the 1940s we started learning how to use that energy.
We have been stalling ever since. It's like we stopped developing automobiles because some people became afraid of them.
Yes, the GPP's numbers are definitely off. We had astronauts spend four days each way on the moon missions, so it isn't quite as bad as that. I do recall reading though that a trip to the outer planets of our solar system with our current technology would leave the astronaut quite damaged by radiation. This is pretty old news, BTW, and TFS reads like some sci-fi fan just got his bubble popped after learning a few facts. Kinda cute, but on the front page of slashdot it just gives all the "/. == digg" complainers more ammunition. As if they needed it...
Caveat Utilitor
I believe that 12 mSv is 0.012 Sv, not 0.12 Sv as stated.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
It should be possible to get to Mars and back, however it won't be cheap. It would probably take the equivalent of as many Saturn V rockets as were ever launched to put enough material into Mars obit for ONE mission. This would include leaving in orbit the return rocket, and sending to the surface a return to obit craft (empty and landed by remote control or by computer). Then sending down the crew on a landing only craft and yet other landing craft with supplies. The crew wouldn't be able to take much back in samples, just dust perhaps. What would be sent back would be digitized data and photos.
Mars is the only planet in our solar system that we COULD visit. There are also the asteroids and here at least the gravity well is shallow enough that a return trip is on par with the visit to the moon. The author of the article is correct in the degree of difficulty of a Mars trip compared to going to the moon. I can't imagine it being worth while to send astronauts to explore Mars because we have done very well using robots. But impossible? No, just very expensive, risky, and not worth the price considering what other exploration could be done with the money.
There are plenty of ideas out there that probably can work. Most of the technology exists, and just needs to be assembled into a single project. Its not even beyond the realm of economic possibility to implement some of these plans they question is why?
What is there on the moon or Mars to make it worth going there. Why should anyone want to live there? Don't say over population even if the population on earth continues to grow at the current rate somehow it will be along time before conditions here would be more cramped then they would be on space/moon/Mars base. Don't say resources its pretty evident that supporting one person on a space/moon/Mars base would take more resources from Earth that keeping that same person right here on Earth. The only reason to do it is for practice colonizing and for the investment required it probably makes more since to try and simulate things here on Terra.
There are for the most part know ways to build and power a multi-generational ship There is lots uninterrupted solar power and other radiation out there to scavenge for your day to day needs, and you could bring enough nuclear fuel from Earth to propel the craft. The trouble is where do want to go. Oh and your going to live the rest of your life in this box, you will never see the destination, nor will your children, their children, their children's children, and likely ten more generations after that. That is if you pick someplace nearby and NOTHING goes wrong. Who wants to take that risk and for what?
Repeal the 17th Amendment TODAY! Also Please Read http://www.gnu.org/philosophy/right-to-read.html
We have the technology. It is just impossible to send humans and their living quarters and their supplies and a research station and a return vehicle and return trip supplies on a SINGLE chemical rocket. Once you start using more than one chemical rocket for this list, even at just two, it becomes possible. (Unless you can do the smart thing and use a single nuclear rocket instead.) We already have demonstrated that we can resupply a spacecraft in orbit, do docking and assembly in orbit, do precision landings, survive long enough for the trip in space etc. The mission to Mars probably shall not use chemical rockets, but if we decide to use that technology, there are plenty of possibilities to make it happen. We can even colonize Mars with current *propulsion* technology (but new technologies are required for other aspects of colonization) : Aldrin Mars cyclers (basically Mir, ISS like stations in an interplanetary orbit) are sufficient for regular travels or resupply missions.
Gentlemen, you can't fight in here, this is the War Room!
Yes, of course you're entirely correct; whole body exposure to 10 Sv is lethal. Your parent is way, way off.
From your parent's post's own link - "Actual radiation dose measurements of Apollo crews measured by onboard dosimetry were, on average, 12 mSv." That's for the entire two way flight, not per hour.
He may have been talking about the calculated dose of 6 Sv in space at Earth's distance from the Sun if a major solar particle event occurred. That's 6 Sv TO THE SKIN PER EVENT, not per hour, or 0.9 Sv to the bone marrow. Or intersecting the path of a coronal mass ejection or solar flare, you could take 10's of Sv if floating naked in space, but fractions of 1 Sv inside a spacecraft. Cosmic ray exposure could be between 0.3 to 1 Sv per YEAR. While all these considerations are very serious, they are far from the cataclysmic levels portrayed by the poster.
This summary is such FUD, and the article is nearly so. The author is a Medical Doctor, and if Doctor's had their say humans would have never gone to low orbit in the first place! Physics tells us Moore's Law is not a Law, but rather an idiom that expresses human ingenuity in the field of electronics. Moore's Law does not say transistors can get indefinitely small, it says people can build cheaper and cheaper transistors on larger and larger circuits. I can double the payload capacity of LEO vehicles tomorrow. Give me a 747 at 40,000ft and a rocket, and I'll put up twice the cargo for half the cost of a conventional rocket launched from sea level. Physics says I can do that. I'm not sure what point the author is trying to make with Moore's law, but the comparison between human ingenuity in spaceflight and electronics, and the laws of nature, is mute. Just because it hasn't happened, doesn't mean it is impossible.
Mistaking a large Keynesian space program that explicitly prohibits large leaps in engineering is a common mistake people make when it comes to the impossibilities of space travel. The space station was built, in part, because NASA and Congress didn't know what to do with the large 'space truck.' What do you do when you've got giant reusable vehicles with a HUGE cargo hold? Apparently, you build a space station with it!
We have been living continuously in low orbit for decades without a single fatality. The only Americans who have ever died in space died coming and going, but once you’re up there it has been statistically much safer. One would think moving a group of humans 60-100M km over 9-15 months would be quite possible. We've been living in hostile environments here on Earth for almost a century now with submarines, where a person can't exactly go out for a walk 600ft under water. And in the last 40 years or so, the crews of big submarines have continuously lived underwater for months on end. We know how live in enclosed environments for long periods. If 200 men can go months on end without killing each other, I think a dozen over the hill astronauts might be able to do the same.
The hard part of going to Mars is leaving Earth and then landing safely, landing being the most difficult but NOT impossible feat. Physics tells us that all the elements needed to create breathable air, fuel, water and return fuel for indefinite exploration of Mars can be found on Mars. Physics tells us the power needed to make these compounds can be made on Mars as well. All with ‘current’ technology despite the "low grade" resources, as claimed by the author!
Physics tells us all the hazards of interplanetary travel can be reduced or mitigated. Physics tells us radiation can be reduced with shielding, as can micro meteorite impact dangers.
If you want to really learn what Physics says we Can and Can't do, I'd suggest checking out on of the all time greatest book on the subject, "Spacetime Physics" by Taylor and Wheeler from you public library.
You think that's science fiction? How about this. Physics tells us it's possible to put all the DNA of earth on a tiny little probe the size of a dime, complete with tiny robots, that can be quickly accelerated to large fractions of c and travel between stars in decades. These probes can smash into planets and build life for us. Why send our descendants in large cumbersome bodies when you can send the information needed to create them. The technology to do this doesn't exist yet, but we are developing it Now. And physics doesn't say anything here is impossible.
The Navy owns the reactors. They bring in civilian contractors for the critical repair jobs and overhauls, supplemented by military workers. Navy Nuclear Power techs (of which I was one) receive a lot of training in two years, but a Bachelors / Masters / PhD it is not.
How does it feel to be a liar with pants constantly on fire?
building the thing in space with chemical rocket or projectile launch methods and then assembling it in orbit
Do you have any idea of the time and complexity needed to do even minor operations in space ? (i.e. doing some structural work on a space station)
This would take ages. Really, several generations. And cost trillions of dollars.
it sound cool, but it just isn't realistic.
Segmentation Fault in "Life, Universe and Everything" at line 42. Don't Panic.
This article is dead on. There hasn't been major progress in making rockets more efficient since the 1960's because the basics of chemistry and physics.
If we spend hundreds of billions of dollars, we might be able to send a select few men to Mars, but it would be like the lunar landings in the past. It will be a one time event then people will realize that it is a waste of money and resources to do it again.
The current technology won't work to make space travel apart of our daily lives. It won't support advances like suborbital commercial airplanes, space tourism, colonization, or mining the Moon and comets.
There has to be major advances in technology to make space travel that are order of magnitudes more efficient before any of these dreams becomes a reality. These technologies are mostly theoretical and probably won't be available during our lifetimes. Until then, we will just continue to spend billions to send a select few into space like we have been doing since the 60's.
Voila, a nuclear rocket with no radioactive exhaust.
False. Quartz is also transparent to neutrons, which will be copiuously produced by the fission reaction going on. I haven't looked at the link, and don't need to. If this thing is fission powered, there are neutrons. If there are neutrons the exhaust is going to be radioactive, unless the gas is pure helium-4, in which case the whole gas vortex UV thing is irrelevant. You can run 4He through a pebble bed reactor and have it come out non-radioactive (more or less.)
Blasphemy is a human right. Blasphemophobia kills.
Because at some point the sun will turn into a red giant and swallow the earth whole.
Just as interstellar distances are unimaginable to most of us and our human-environment-size-and-time-scaled brains, so is time. We are about halfway through the lifetime of our sun, which means we still have a comfortable one to two billion years before any noticeable change.
We could wipe out all life - down to the bacteria and one-celled, I mean absolutely freaking everything - on the planet and there would be enough time for another sentient species to evolve. They'd have a lot less time, we don't. I really don't think we should worry now. Two billion years is plenty of time to come up with interstellar travel, even without trying.
We will be completely and irreversibility erased from the universe.
A lot of people find that thought rather uncomfortable.
If you worry about the sun going out, why not worry about whether or not K > 0? If there's going to be a "Big Crunch", then we'll be wiped out whether or not we go to the stars.
I honestly think there's something else to the whole space exploration meme. It is a symbol of freedom, because it is so huge that for alle we care it's unlimited in size and time. On a planet where we are just about to map the last few remaining white spots, that means a lot.
Assorted stuff I do sometimes: Lemuria.org
Also, compared to some other "adventures", [wikipedia.org] the whole thing would be rather cheap
The challenge for space travel is to get buy-in from the broader population, and to do that it has to have the same visceral, senseless emotional response that warfare has. War is mate competition carried out by other means, and as such engages our deepest emotional responses.
While exploration is daring and dangerous, the vast majority of people can't participate in it in an active way. We sent 12 people to the Moon, compared to hundreds of thousands rotated through Iraq.
So from my point of view the problem with exploring other worlds is that we aren't doing enough of it to engage a large enough segment of the population. If some country were to commit to militarizing the Moon, say, we'd see a vast increase in resources flung at space travel, and at this point I'm not sure that wouldn't be a bad thing. Even done by an organization as stupid and inefficient as any standing army, it would be cheaper and vastly less destructive than even a fairly tiny war.
Blasphemy is a human right. Blasphemophobia kills.
I thought the big problem with nuke ships was the momentum incurred, and shedding it in time to land without detonating on impact. Slowing down in space is a sonofabitch. On a trip to somewhere like Mars, you have to expend nearly as much energy slowing down as you did speeding up. You can't air brake into mars without one HELL of a big shield/parachute due to the relatively low atmospheric density (about 1% of earth). You basically gotta turn around and thrust directly 180' into your forward path until you're slow enough not to escape the gravitational pull of your destination.
Seriously? Let's expose thousands of humans to radiation for several (hundreds, or more likely thousands) generations. Sure, most of them will die horribly of cancer, but perhaps they'll evolve radiation resistance. Those pesky ethics are holding us back!
You sir are a horrible person.
Insects are more resistant to radiation because they have simple bodies, short life cycles, and huge numbers of offspring. We're not likely to ever evolve radiation resistance. Or superpowers, unfortunately.
The article is IMO incorrect because it concentrates only on chemical reaction motors. There, of course, their answer is correct. But that isn't the only way to move around in the solar system. One question I ask my intro physics students is to contemplate the light sail as a means of propulsion. To do this, one simply works out the balance between solar gravity and radiation pressure to determine how thin a sail has to be in order to directly support its own weight (and the answer, of course, is "very, very thin":-).
However, this isn't the end of the problem. I then ask them how much force is required to remain in orbit. The answer (neglecting the tiny amount of atmospheric drag in near earth orbits and e.g. tides) is "none" -- orbit is free fall where the centripetal force required to bend the trajectory into a circle is provided by gravity. A feasible light sail can be built that can exert enough force via reflected sunlight to provide an acceleration of (say) a millimeter per second squared for it and its payload in a scalable way, or even more (with sub-micron sail designs). Not much, but given 86400 seconds per day, that is as much as 86 m/sec (or nearly 200 mph) delta-vee per day, for free, every day. One can add a kilometer per second every two weeks, and that's enough to reach anywhere in the solar system in time, especially if you amplify it with a gravitational slingshot off of (say) the moon.
Sure, it would take too long to move humans around, but that isn't the challenge -- we can move humans around now at large but not impossibly large expense, at least as far as Mars or Jupiter or Venus, even using chemical rockets although there are probably better solutions than chemistry in the long run. The only really hard part is getting things into low Earth orbit -- once there you are "halfway to anywhere" as Heinlein liked to put it (virial theorem) and light sails mean getting the rest of the way is scalably/reusably "free" if you don't care about taking order of years to get there. Light sails would let us move everything that isn't a human to e.g. the Moon or Mars to set up a more or less permanent base and maintain a long-term line of supply. Who cares if your food and water take years to get there, as long as they get there cheaply enough?
A second thing that would change the economics (aside from either new physics or radically new ideas, e.g. a fusion-driven relativistic ion drive that again uses free or abundant energy to eke the maximum possible reaction thrust out of reaction mass by accelerating it to close to c where it has a lot of momentum per particle) would be to build light-sail driven robots to mine the asteroid belt for raw materials so that we wouldn't have to lift e.g. steel, nickel, and possibly even water up to Earth orbit. Those robots could equally well deliver mass back to Earth at e.g. the Earth-Moon Lagrange points and allow extended permanent habitats to be constructed there that are a light sail away from anywhere.
The only thing preventing us from settling the solar system is time and the will to do it -- we could do it now for a tiny fraction of what our military forces cost us every year. Sure, it would be good to find solutions to the time problem -- it's easy and cheap if we don't mind transit times of decades, so perhaps working on various forms of suspended animation would permit humans to take the light sail route as well as their food, clothing, water, air, and construction materials. A Lagrange point colony with a decades-long, robot-filled pipeline of raw materials could create a steady flow of humans moving out to permanent colonies throughout the solar system on a timescale of centuries.
Or, as some clever human posted yesterday, perhaps a flying saucer really did crash at Roswell. If so, then interstellar travel is indeed feasible somehow, which means that there is likely a solution waiting in new physics. If the federal government would just 'fess up
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
No. Check out DeltaV for earth and moon. Even worse remember that everything will have to go from earth to moon, then out. Your plan actually makes it more expensive. It would be cheaper to just launch from the earth to target. Unless you think that all the stuff you want to take to space is already sitting on the moon waiting.
The challenge for space travel is to get buy-in from the broader population, and to do that it has to have the same visceral, senseless emotional response that warfare has. War is mate competition carried out by other means, and as such engages our deepest emotional responses.
No... not really.
A HUGE part of population is very interested in space travel COMPLETELY VOLUNTARILY. In fact, find me one kid who would not choose "Astronaut" as a profession if it was available.
You don't need it to be anything like war - just as colonists of the "New World" didn't go there because of some antiquated patriotic notion. They went to find a better life for themselves or to prove themselves. Fuck... many of them went to GET AWAY from antiquated patriotic notions.
As for "mate competition" - way off there. Wars are no longer fought in order to "git the'r women an' food".
Nor are they fought to "preserve the species" - wars are political tools. Have been since humans invented guns and by doing it made "warrior noblemen" obsolete.
And the quote goes "War is not merely a political act, but also a political instrument, a continuation of political relations, a carrying out of the same by other means."
While exploration is daring and dangerous, the vast majority of people can't participate in it in an active way.
Depends on your definition of "active participation".
By that same logic, people voting for their political representatives are not "actively participating" in politics.
Same as people who donate to various causes don't "actively help".
Give the humans a way to donate their time and money to such an endeavor. Hell... People donate both to deletionists at Wikipedia.
We sent 12 people to the Moon, compared to hundreds of thousands rotated through Iraq.
Besides obvious logistic differences here, most people that were sent to Iraq would actually like NOT to be there.
Those 12 were volunteers chosen from thousands others who would swap places with them in a blink of an eye if they could. Just ask the other 12 that went there without actually landing.
So from my point of view the problem with exploring other worlds is that we aren't doing enough of it to engage a large enough segment of the population.
"A large enough segment" is very much engaged - if by that you mean interested in space travel.
If you mean "sent to outer space" well... compared to your "engagement in war in Iraq" example - it costs a little more per person than a just some jet fuel, uniform, gun, ammo and a couple of months training to send someone to space.
If some country were to commit to militarizing the Moon, say, we'd see a vast increase in resources flung at space travel, and at this point I'm not sure that wouldn't be a bad thing. Even done by an organization as stupid and inefficient as any standing army, it would be cheaper and vastly less destructive than even a fairly tiny war.
Why militarized?
Look up at that Clausewitz quote again. It's POLITICS by other means, not war by other means.
Politics is also "Hey, let's go there TOGETHER". There really ARE friendly ways of competition available to humans where you don't even have to kill anyone.
Mit der Dummheit kämpfen Götter selbst vergebens
Go to more of a "faith based" space travel, not encumbered by "Science".
putting the 'B' in LGBTQ+
If there are neutrons the exhaust is going to be radioactive, unless the gas is pure helium-4, in which case the whole gas vortex UV thing is irrelevant
If the gas is hydrogen it will not become radioactive. When a hydrogen nucleus captures a neutron it becomes non-radioactive deuterium.
Hydrogen has the added benefit that it's the best gas for a propellant, so it would be used anyway.
In breaking news from 150 years ago: "The clash of two titans — physics and chemistry — are major barriers to human heavier than air flight, and may well make it impossible ... at least with current technologies."
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