Mars has given nuclear spacecraft engines a new lease on life, with nuke ships being named as a top priority – along with electrical propulsion – in a new report that recommends what NASA should focus on in coming years. The two propulsion systems prioritized in the 468-page report by the National Research Council (NRC) – which …
Fine. Then ship the fuel and the engine separately using known/proven chemical boosters and "safe" routes to orbit, then assemble there.
Jeez...I mean it's not rocket science is it...oh wait. It is.
Sadly, the last sentence in that article is all too regrettably true. Mankind's short sightedness may well be its downfall.
Even if I have felt great excitement with space exploration starting with Sputnik and perhaps finishing with the moon landings, but how could the exploration of Mars, a completely worthless planet, in any way prevent Mankind's downfall. If we are concerned with Mankind I think we should concentrate on Mankind on this planet. Then again you are right "Mankind's short sightedness may well be its downfall", true from the very beginning, but that has nothing to do with Mars.
Am I being mean, I think I need a beer.
Far from being "worthless" Mars is the only really viable place for Mankind to colonise, as it is (in astronomical terms) just next door, and has the potential to be terraformed using current or near future technology, to the point where living on the surface could be possible within a few generations. Contrast with the Moon where any colony would always be confined to artificial structures, and at the mercy of the low gravity (which has deleterious effects on human bodies).
It's all very well the boffins going "ooh look at star such-and-such, it's got goldilocks planets which can support life!" the reality is we are not sufficiently advanced to even consider travelling to any of these.
You say "I think we should concentrate on Mankind on this planet."
Yes, but we are in the classic "all the eggs in one basket" situation at the moment, where firstly, any extinction level event (whether from orbital impact or through our own foolishness) would wipe us all out, and secondly, we are running out of room and resources.
We either need to drastically limit the population growth in some way, or find another planet to move to. Doing this now, before it's too late, would seem sensible. But as you and the previous poster have said "Mankind's short sightedness may well be its downfall".
"potential to be terraformed using current or near future"
Arrant nonsense !
"we should concentrate on Mankind on this planet"
How can you do it without going to space and to Mars in particular?
I think that you might find that no matter how much you terraform Mars, even assuming that we are/will be capable of that, the fact that Mars has no significant magnetic field may well make living there "tricky" long term.
Colonising Mars would certainly be one mean job, and terraforming on a scale that would make the planet's surface habitable would take something on the order of thousands of years, if indeed it would be possible (can Mars's gravity keep an atmosphere?), however, living in large underground caves or bubbles in large enough numbers for humanity to survive an Earth catastrophe would be possible.
Of course the key to that, especially with much less solar irradiation for plants to grow etc, is massive amounts of power, and that means nuclear power on a gigantic scale
I agree with you on all you wrote, but I'm not sure about this:-
"We either need to drastically limit the population growth in some way,"
I've noticed that this Malthusian view seems to be a popular theme amongst the Reg's commentards. Firstly, I really don't like the sound of "drastic" action. Secondly, it might not be necessary.
After a little reading around the subject. I read about Ester Boserup, for example. From her article in the Wikipedia, "In the Malthusian view, in times when food is not sufficient for everyone, the excess population will die. However, Boserup argued that in those times of pressure, people will find ways to increase the production of food by increasing workforce, machinery, fertilizers, etc."
I also read about Julian Simon. From his entry:- "Simon challenged the notion of an impending Malthusian catastrophe—that an increase in population has negative economic consequences; that population is a drain on natural resources; and that we stand at risk of running out of resources through over-consumption. Simon argues that population is the solution to resource scarcities and environmental problems, since people and markets innovate."
It seems true that technological advances and population increases are correlated, but which is cause and which is effect? Could it be that population increase is driving technology forward? Why hasn't the last century of geometric growth in population resulted in a 'Malthusian catastrophe'?
While what you say is generally true, I think that you probably reach the limits of diminishing returns utilising that and solely that.
The planet is already at a point where significant swathes of it do not have sufficient fresh water for the population as it currently stands - look at Australia. While you are right that innovation is often bred from this, there is only so much we can do, and the negative effects of these innovations are often not well understood and do not come to the forefront until significantly later.
"Why hasn't the last century of geometric growth in population resulted in a 'Malthusian catastrophe'?"
Possibly because at that time, the planet was underpopulated and, thanks largely to the Dark Ages, not as technically advanced as we potentially could have been. The last century brought massively increased population growth and invention to support that. We may well have now 'caught up' as it were.
Could it be we are now at the point of saturation?
Cheers for the reply! Please allow me to take your example of water supply in Australia, to try and illustrate the point how technology could change things.
Here's a map of rainfall down under:-
Now here's a link to the 'Great Man Made River Authority'.
Or the Wikipedia article about California's central valley:-
Perhaps the Aussies could spend some of that coal and iron money on a few pipes? The thrust of the anti-Malthusian argument is that they won't do that, unless population increase drives them to do it. I think that is an interesting argument.
Charity begins at home...
Until we can make a living in the comparatively benign environment of Antarctica with its oxygen thrown in for free, hoping to hack it on Mars seems more than a little over-optimistic.
Not to mention the fact that Mars is not massive enough to hold onto anything other than a very thin atmosphere. Even if you managed to replace what is there (mostly CO2 IIRC) with a nice nitrogen/oxygen mix, you'd still asphyxiate pretty much straight away. Trying to hold onto a thicker atmosphere would be a fool's errand, as you would be continuously losing mass to space. Assuming you had some miracle technology that could convert rock into breathable gases, you'd essentially be subliming the planet away into space, making the problem worse as you waste more and more mass.
We've just dragged our selves out of the gravity well trap, and you want to go sit in another one ?
To the asteroids !
You can't dodge Malthus forever
Or as Kenneth Boulding put it: "Anyone who believes exponential growth can go on forever in a finite world is either a madman or an economist."
Even if you assume we out-innovate any obstacle to growth, fundamental physical laws will get us rather soon: http://physics.ucsd.edu/do-the-math/2011/07/can-economic-growth-last/
As was pointed out these magical system don't work or have very bad effects of other areas.
For example from Central_Valley_Project link you provided:
"Despite the benefits of the Project, many CVP operations have resulted in disastrous environmental and historical consequences. The salmon population in four major California rivers have declined as a result, and many natural river environments, such as riparian zones, meanders and sandbars no longer exist."
In other words to live one lifestyle, others had to pay. This will eventually cause enough trouble to trigger wars or the collapse of societies. Man has been changing his environment for millennia, but the repercussions are only now being felt in some areas.
Go back a few centuries and the vast majority of Europe was covered in forests as dense and diverse as those in the Amazon, our ancestors got away with deforesting a continent as most of the planet was still mostly untouched. If that gets repeated in South-America, Africa and Asia the effects could be devastating all round.
Going purely by what I see as your incredible naivety on the real world issues, I assume you also believe in the Sky Fairy and/or Intelligent Design. Where as in reality; humans are just animals, a few slightly more intelligent than most other species, but the same basic rules apply. When the resources needed to live run low we either kill or steal from our neighbours or die off.
The one difference between us and the other species, is that we should be smart enough to stop breeding beyond what can be sustained, and before we need to fall back and act like all the other critters on this planet.
There's a problem with Malthus' idea
The total carrying capacity of earth, population-wise has nothing to do with why people are unhappy with the current population growth. If yo want to sum it up, when population grows, we find the changes made to feed them result in changes to the earth and previously uninhabited areas that we do not like.
We're nowhere near population saturation. We have not even begun to exploit all food sources. When we run out of plankton to eat, or CHON-burgers, then it might be an issue. Any words to the contrary are just histrionics. However, the changes we've already made have been unsettling enough to generate a reaction, and justifiably so. If population growth means that we render an excessive number of species extinct (I wouldn't mind if mosquitoes went extinct) and that we turn treasured environments and habitats into cultivated space, we as a species lose a lot of things that we should come to regret.
We, of course, should be better stewards of this particular planet. The development of interplanetary resources is the single best way to do this without also putting restrictions on people that won't be followed, or that are counter productive. For example, if intelligent people are concerned about population growth, and forbear having children in order to do their part, then the earth will eventually be overpopulated by the slightly dense that just "didn't get the memo". They were probably watching some trashy reality show at the time and couldn't be bothered...
Even in circumstances where legislation forces the population as a whole to reduce itself, cultural issues arise to confound the best-laid plans. "One Family, One Child" turns into "One Family, One Boy, now that he's 18, where are the girls?"
On a positive note, the people lamenting the loss of the old-growth forest in the US should know that there is more forestation in the US than there was in pre-Columbian times.
There is gigantic nuclear power in the center of earths orbit :)
Quite like your text, I also liked the book "The read planet".
But Mars is to small, too cold, and does not have anything to support human life. There is not enough water and there is no shield against radiation, nill, nothing.
The way we have managed (and sometimes failed) to send probes and satellites to Mars is fine.
But to send humans there I just cannot see as anything more than a political decision.
It was that way with the moon too.
I would leave Mars to China as far as landing humans is concerned. I believe the political gain would be nill.
I would support an international Moon base, for assembling larger satellites and so on.
But the one thing that intrigues me from this Mars book was the space lift or space sling.
That I could support. It would be fun to know if we had the technology and the money to build one.
When it comes to those planets in other solar systems it is quite clear that we would first send unmanned stuff there before any space ship with humans on board.
I like science fiction very much but you have to leave at least on toe attached to this earth.
And yes if Mars seems to be a good home some day, then we must have fucked it up real bad.
Australia comes to my mind, and then again not at all, not not.
Assemble in orbit
Rather than putting the nuclear fuel in the reactor robotically on successful ascent they could even get the chaps on the ISS to do the final assembly.
Who would have thought?
That the years 2010+ would be spent rediscovering 1950s era technologies? And complaining they're too difficult?
I even saw "Landing on Moon possible by 2020" as a *serious* headline the other day.
We need a "what a buncha losers" icon.
Stuck in the 1950s with their measurements as well. Perhaps they can't afford to upgrade to SI units.
...only really an upgrade if you need to count on your fingers. ;-) (Or have built a biquinary machine.)
Perhaps a century or two from now, the later 20th and start of the 21st centuries will be refered to as the Second Dar Ages.
The NASA OCT...
The author is not emphasizing that this is a publication driven from NASA's OCT. The OCT hasn't driven a report with this level of specificity in years. It doesn't mean that NASA is confident that it will secure funds to achieve these goals, but that the NASA administrator was confident that he wouldn't be fired for daring to conjecture on such an expensive level.
Looks to be an interesting read. The budgetary requirements for enacting these proposals seems far away. The USA does need to pay down the massive debts assumed in the August 2008 financial meltdown.
Final exam time.
Do this or fucking die off and give the beetles a chance.
Or at least feed the accountants to them.
And the lawyers.
and- oh, you fill in the rest...
Oh, its the tame nuclear engines they're on about.
I can't be the only one hoping this was about Orion.
(No not the capsule, the nuclear bomb powered one)
Which was first?
Footfall or Project Orion?
I can't be sure the wikifiddlers are accurate.
project orion was first
reading this at the moment, one of the characters "Fox" upon hearing of the ship starts referring to it as Orion.
top book by the way, recommend it for anyone that hasn't read it (same goes for any niven/pournelle book though )
Yes, Footfall was a good 20-30 years after the concept of Orion. Freeman Dyson wrote a paper in the 60s on using thermonuclear devices to achieve interstellar voyages - you can be sure the maths and physics stand up! Carl Sagan pointed out that this would be a rather clean way of disposing of nuclear weapons inventory.
"a rather clean way of disposing of nuclear weapons "
Erm... I hopes that he added "Once the rocket is far from earth gravity well"...
Project Orion was on the same line as those "Civil engineering nukes" - a good idea as long as you don't mind the radiations.
Disclaimer : Don't take me wrong - I'm not of the "nuky=baddy" team, and I'm in favor of the developpement of "clean" NTEs...
forget the constituents
Another arguement for putting the private sector in charge, to disempower ALL the constituents. I see no reason why people's opinions should be allowed to influence anything beyond their own actions, anywhere any time.
Bah. That sounds like a good reason for China to take the lead.
Fusion-powered starship would be better, cleaner and safer; it can be fueled with helium-3 available on Moon and Jupiter. http://www.youtube.com/watch?v=Uqnk19hn7Rc
... and Matter/Antimatter reactors will pave the way for interstellar travel.
Perhaps we should start with mature technologies before switching to fusion?
But what about world hunger
... who cares
I want my nuclear spaceships and I want them now
try the military budget
There's enough in there to end world hunger AND build a nuclear rocket to Mars.
Or the War on Poverty
And admit that after hundreds of billions of dollars the poverty level hasn't really changed that much along with the fact that the major reasons for a lack of food in the third world are corrupt regimes that prevent markets from working and/or a lack of cheap energy to produce said food.
Indeed, as Blackhawk Down
As Blackhawk Down shows, it's not the US military budget taking bread from the mouths of toddlers in the third world, it's more like the African warlord's military budget that is killing people.
Recently a branch of the Kenyan civil service estimated that the country could support almost 300 million people. That's twice the population of Russia. At the minute Kenya's population is ~41 million.
Anyway. So you decide to divert the entire world's military budget to feeding people. Then what? Will people suddenly become virtuous, industrious, _and_ peaceable? There is vast wastage in all military budgets and we should spend more on disaster relief and development, but spraying resources around will not magically solve the world's problems.
Let NTR Die
NTR is a pain and it has limited Isp. Sure, cooling is a little easier because your reaction mass carries the pile's heat with it, but at ~2000sec you're still going to need a lot of reaction mass and time to get to Mars. Just let it die. Focus on compact nuclear electrical sources and solve the reactor cooling problem. You'll be a lot better off in the long run.
2000s Pretty Good
That's still a lot better than chemical rockets, plus the matter of how much total time the engine can fire raises its head. If you can make an engine that fires at full power for far longer than, say, half an hour, like maybe for 10 hours, it can be a BIG win.
"solve the reactor cooling problem."
Easily said, but is there really an alternative to dumping reactor heat into an exhaust? What else can you do with it?
The reactor cooling problem can be solved with efficient thermoelectric converter. http://www.youtube.com/watch?v=Uqnk19hn7Rc
"Easily said, but is there really an alternative to dumping reactor heat into an exhaust? What else can you do with it?"
Bloody big glowing radiators on the trusswork between engine house and living space.
Nuclear electric? Life's too short
There's plenty of other cool things in the research pipeline. Open cycle gas core NTR springs to mind, or weirder things like fission fragment reactor based things. Both are likely to be better than a couple of thousand seconds. The important thing is that practical work be done on these various designs rather than purely theoretical... like most nuclear technologies we've more or less failed to innovate in the last 30 years (or longer!) because of their bad reputation and image.
That said, I'm terribly keen for mini-magnetosphere plasma propulsion sails to work. That would be all kinds of awesome.
"Bloody big glowing radiators "
Most of what we know as radiators work by convection or conduction, neither of which will operate in a vacuum. That leaves true radiation, i.e. dumping the heat as infra-red. "Bloody Big" doesn't begin to describe it!
I think his idea was to radiate the heat into the ship's crew compartment which one assumes is not a vacuum.
"radiate the heat into the ship's crew compartment"
One may indeed assume it is not a vacuum. When it ends up as part of a nuclear reactor cooling scheme, one might plausibly call it an 'oven', though perhaps 'kiln' or even 'furnace' might be more appropriate.
High efficiency radiators in a vacuum are plausible, but exceedingly non-trivial to engineer. One of the better designs looks like a spray of low-vapour pressure coolant; the droplets having a large surface area for radiation, and as they won't boil away to any significant degree you can catch em in a scoop to return em to the coolant loop. Does away with all the mass and inertia of a really big solid radiator system, certainly. Not quite as straightforward as an open-cycle nuclear reactor though.
Phlogiston pumps discussion next?
"Most of what we know as radiators work by convection or conduction, neither of which will operate in a vacuum."
Just because a household appliance is called "radiator" it does not mean that it really is one.
Radiating heat into space is quite possible. In fact, that's how we get the heat from the Sun here on Earth. The space is black = very cold and radiating into space is actually the best way of radiating heat, as one can easily deduce from how cold it can get here on Earth on a clear night.
Even inside our atmosphere, as you heat things beyond a few hundred degrees C, radiation becomes the main component of heat transfer.
So, dumping heat into space without throwing away hot mass is very much possible and the hotter the stuff you want to cool is, the more efficient it is to use radiation to cool it down.
It'll all end badly.
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