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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.
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?
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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."
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.
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
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!
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.
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
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
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
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.
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.