New Mars Forums

Thankyou Rob for this interesting discussion. You have raised many good points and I do respect your opinions on power generation.
   And you are quite right that it's probably time to move on! I look forward to hearing more from you soon.
                                                            Shaun   

I think AndyM is right. And I think Dr. Zubrin is largely correct, too.
   Life here on Earth, for at least most of us in the developed world, is relatively safe and uninspiring. And it's mentally and spiritually stultifying to think that almost anywhere you go, you can buy a coke and a hamburger and watch CNN!
   Just knowing that out there somewhere, there are people facing hostile conditions and exploring places where nobody has ever been before, is enough to lift that feeling of bored pointlessness. And, as in the case of the Wild West which was glamourised beyond recognition by east coast journalists, the  Martian frontier will also attain a mythical significance in the minds of Earth-bound "stay-at-homes". But it won't matter that the dream exceeds the reality; it will be enough just to have the dream.
   That's what's wrong with us right now: We don't have a dream.
                                         

I had vague recollections of Project Orion involving controlled nuclear explosions to accelerate a space ship but couldn't remember the details. In any event, the idea had always sounded crazy to me and so I filed it away in my memory under "P" for "Preposterous"!
   Anyhow, I did some research on this last night and found that Project Orion is NOT quite as absurd as I'd thought. Although it does involve ejecting a series of smallish fission bombs behind the craft and exploding them; if done in space it presents no radiation danger to Earth. And the resulting performance is absolutely astounding! Whereas the Isp (specific impulse) of our best chemical rockets is about 450 seconds, Orion's theoretical Isp ranges from 10,000 to possibly 1,000,000 seconds!!
   In fact, in 1960 when atmospheric nuclear testing was rife, it was even proposed that Orion might be launched from sea-level (maybe from a floating platform remote from civilisation). It was calculated that about 350 nuclear explosions would achieve orbit and increase atmospheric radioactive contamination by only 1% compared with the going rate at the time! The cost would be about $175 million, less than a shuttle launch, but (and here's the punchline) while a shuttle delivers 20 or 30 tons to orbit, Orion could deliver thousands of tons!!
   150 people or more could cruise around the solar system at great speed and in spacious comfort in Orion's huge passenger module because the majority of the initial mass of the craft is payload! Forget Hohmann transfer orbits; you head for Mars in virtually a straight line and get there in days rather than months! And Orion is a laughably cheap thing to build compared to a shuttle.
   Actually the British Interplanetary Society's plan, called Daedalus, was for tiny fusion bombs to do the same as Orion's fission bombs, except they advocated a more efficient magnetic nozzle to direct the expanding plasma. The technology for this doesn't yet exist, but Orion has been possible for 30-plus years.
   In fact, using a scale model with conventional explosives, an American research team in the 1950s achieved a controlled 100 metre flight using 6 bombs ejected in sequence; thus proving its stability! Only politics stopped Orion's development; not a lack of technology.
   For the full story on this, go to:-
My Webpage

I wasn't sure whether or not to continue this line of argument since it seems a bit off-topic. But then I thought about nuclear waste disposal on Mars in the future, so discussing nuclear waste management does have relevance to Mars exploration ("Contrived logic!", I hear you all cry!!)
   As I understand it, Rob, the plan with "hot" waste is to first powder it and then mix it into liquid glass; making chemically very stable glass "bricks". Then you locate a continental plate which is stable over geological ages, drill a hole some metres across and maybe a kilometre deep (straight down into solid bedrock) and then begin burying the bricks. The bottom of the shaft is first lined with 2 or 3 metres of reinforced concrete, then a stack of bricks, then more reinforced concrete, then more bricks, then more concrete, etc. etc. The last few hundred metres of the shaft are then filled in with yet more concrete; forming an impregnable plug.
   There are regions of Earth's continental plates (e.g. in Greenland, Canada, and Australia) which have been largely undisturbed by volcanic or tectonic activity for periods of maybe 2 to 3 billion years. The radioactive half-lives of fission products are typically many orders of magnitude shorter than this.
   In other words, if you have half a brain, you should be able to find any number of places on Earth (and more so on Mars which probably has less vulcanism and no discernible tectonic activity) where you could safely bury nuclear waste for many many times the prospective life-span of the human species. Obviously there will be costs associated with this deep burial but we are good at drilling holes and I don't see these costs as being prohibitive.
   As for all these cowboy politicians stirring up irrational fears in their electorates any time somebody suggests a nuclear waste repository in their State, it makes me despair of humanity's common sense! These same people probably have more radiation in their homes from naturally occurring radon gas percolating up from the rock under their cellars than you would ever get out of a properly constructed nuclear waste repository!
   I regret, Rob, that I just have to agree to disagree with you about nuclear power. A properly conducted nuclear power industry IS an environmentally sound option; most of the opposition to it is just pure emotion. (No offence intended.)
                                   

I'm a little confused about Bill White's hydrogen generator. Hydrogen is a wonderful
fuel on its own in Earth's atmosphere, and a marvellous fuel in space when used in
conjunction with an oxidiser such as liquid oxygen.
   However, in a tenuous atmosphere of almost pure CO2 (i.e on Mars), hydrogen is
effectively an inert gas. What will we use for an oxidiser?
   And Disland's idea of relying on pedal power sends shivers up my spine! By the time
we're reduced to exercise bikes in order to contact Earth, I suspect the contact will
only be to finalise funeral arrangements!
   No, at least in the early stages, Austin Stanley (and Dr. Zubrin et al. ) are clearly
correct in advocating a fission reactor for electrical power. In fact, it may be some time
before a more practical solution can be found. And what's wrong with nuclear power
anyhow? It's not some satanic abomination! As long as adequate provision is made for
the disposal of spent fuel, it is easily the safest and most reliable power-source. Let's
keep cool heads about this!

I'm all in favour of any sort of lunar transportation system but I suppose you'd have to jettison quite a proportion of the present shuttle structure in order to make it economical.
   As has been pointed out, there is much of the shuttle that, in space, would be dead-weight: Namely the undercarriage, those heat-resistant tiles, the stubby wings, the load-bearing struts, etc. In fact, the whole concept of the shuttle is probably wrong for Earth-Moon transportation. And it's no use trying to ignore the unwanted bits, either. Every unnecessary kilogram of weight will add to the fuel required to accelerate the shuttle out of Earth orbit and into cis-lunar mode.
   In addition, the aerodynamic shape of the shuttle, though essential for atmospheric flight, will only serve to unnecessarily restrict the internal volume of this new space-tug. Perhaps a completely redesigned and purpose-built craft would actually be more economical in the long-run ( ? ).
   I hope I'm not being a wet blanket but we do have to consider the practicalities of this proposal. And, because the shuttle is just so specific to the task for which it was designed, it may be hopeless to ask it to perform in an environment for which it was never intended.
                                                                   ???

Oops!! Looks like I've either asked impossible questions or questions so tedious I've bored everybody into a torpor! ... Sorry.
   Incidentally, for those who've fought off terminal boredom and are still awake, if Mars maintains its present rotation rate, an Earth day will have lengthened to equal a Mars day in about 120 million years.
   If we postpone colonisation until then, we won't need to bother with changing our watches! And our body-clocks will be in perfect sync.! (Oh ... and our politicians may be approaching a consensus on approving a manned mission by then!! )
                                           

I was surprised to read Adrian's comment: " ... the northern polar ice cap is regularly completely vaporised into the atmosphere ..".
   I always thought that a large residual cap remained, even at the height of the northern summer (?).
   So, does the northern cap vanish entirely every summer and then reform every winter? What about the energy required to vaporise 300,000 cubic miles of super-cold ice.
   Surely Adrian must be referring to the superficial frozen CO2 layer disappearing completely each summer; not the water ice (?). Or does he have access to new information I've been too slow to keep up with?

                                                  :0

I think Josh is right, Rex. But why would you be celebrating the possible discovery of water ice at Syrtis Major? Unless that would fit in with a pet theory of yours(?).
   All this stuff from Odyssey is certainly exciting, but are these results pretty much accurate and complete? Or might they discover more water ice if they look harder?
   The point of these questions is that, to be honest, I'm just a little bit disappointed with Mars' northern hemisphere! Sure, the southern hemisphere discovery is a revelation of enormous importance. But could there be more?
   Is it possible that the sediment on Vastitas Borealis is just too thick to allow detection of an underground ocean of water ice with the instruments aboard Odyssey?
   And one more question: Could something other than water be giving us these results? I guess liquid ammonia (NH3) or liquid methane (CH4) could theoretically give a strong hydrogen signal, though its nearly impossible to hypothesise a source for such compounds, I admit! And they wouldn't remain in solid or liquid form under Martian conditions either. But is there ANYTHING else that could even remotely fit the bill? I don't want to break out the champagne and then be told we're actually dealing with underground lakes of hydrochloric acid (HCl) instead of water!!
   Anybody want to put my mind at rest and reassure me? I want to believe! But I'm almost afraid to!
                                                               ???

We're all anxious to be of any small help we can, but without being sure what you are trying to portray, we naturally have trouble spotting errors.
   In any event, errors or not, we think what you're doing is excellent! I'm sure I speak for all of us in saying we love what you've shown us and look forward to more.
   The very best of luck from us all!
                                                     

I certainly admire marsspacestation's optimism and enthusiasm for his starship idea. And I think the day may well dawn when we'll launch such an expedition.
   But I can't help but agree with Phobos and AndyM that the technological hurdles are simply too great at this stage of our development. As mentioned, work on enclosed life-support which can function continuously and without fail for decades or even centuries(!) is really in its infancy. The mining skills we would need to process an asteroid are non-existent, except perhaps as a theoretical concept. Stopping the expedition at the asteroid belt (I assume you mean the one between Mars and Jupiter?) in order to mine and process a few million tons of ore sounds like a monumental undertaking to me. And do we have the skill to accurately send these massive pods of ore back to Earth on automatic pilot, knowing that if one of them slammed into Earth by mistake, we could lose a major city? (Unlikely I suppose, but would people be prepared to risk it?) And would your creditors wait that long to see a return on their money; haven't they spent trillions on this enormous Ark?
   The question about where to aim it is likely to remain unanswered for at least another 10 years. And how good are we at interstellar navigation? Even assuming we know which star to head for, do we entrust the lives of one hundred people to unproven navigational skills?
   I think we would need a huge incentive to even contemplate such a trip at present and, even if humanity's survival depended on it, I feel justified in saying it simply couldn't be done. It would be like asking a 1930s aeronautical engineer to build a 747 jetliner! He might agree that in principle it could be done, but he would laugh at the idea of actually attempting it. Too many gaps in the materials science and other technologies.
   Can't we just concentrate on getting to Mars, for now?! It seems to me we're going to have more than enough trouble achieving even that relatively modest goal; never mind building a real-life "Battlestar Galactica"! Besides, maybe somebody will come up with a wormhole generator and save us the trouble of trudging across the light-years!

Yes, I read the same thing about Earth being heat-sterilised in a billion years.
   I was amazed, too, because when you consider that life has existed here for some 4 billion years, only having 1 billion to go doesn't sound like much! It's like Earth is in old age already.
   But, lately, I'm sure I heard somewhere the opinion that life on Earth had maybe 3 or 4 billion years to go before the sun becomes too hot. Someone has to be making mistakes with their arithmetic! But who is wrong?
   Incidentally, according to one source, when Earth becomes unlivable, Mars should be quite pleasant for roughly 500 million years. That should give us ample time to put an atmosphere around Ganymede or Europa! Then, of course, there's always Titan!