Come up with a CIA analysis that there are Islamic fundamentalists stockpiling yellowcake on Mars, and NASA funding would be increased by two orders of magnitude.
Stranger
Are you asking this because you envision lunar tourism?
Because otherwise, there’s really no other good reason to go back to the moon, except for possibly some MUCH larger lunar base project MUCH further in the future.
Would more exotic fuels help the situation in any way? In Willy Ley’s Rockets, Missiles, and Space Travel he talks a lot about fuels which have substantially higher exhaust velocities than H[sup]2[/sup] and O[sup]2[/sup], such as (be patient, it’s been about 30 years since I read the book) those based on fluorine compounds. Are any of these feasible?
Not if Al Qaeda kept blowing up Wall Street.
(I’d put a smiley on that, but I’m not sure which one indicates “I’m not personally attacking the poster, but am also not turning a tragedy into a joke”)
As technology advances and expands it becomes less expensive as it gives way to newer and more improved technology. If we start with the Apollo timeline and move forward, why after nearly 5 decades has the “cost” not been reduced in relation to the exponential advances in technological ability? Why has it not become easier, safer and less expensive to go to the moon now than it was in the 1960’s?
Because there is no incentive to go to the moon. When we start He3 mining, then you will see corporations spend the money on the tech to get to the moon and back again. Until there is a profit to be made, unmanned probes are a better return on investment.
Because technology can not overcome the laws of physics that dictate that to fling X amount of mass out of the Earth’s orbit at 25,000 mph, you have to generate Y amount of thrust. And so far, technology has not come up with any way to generate Y amount of thrust other than by using really freakin’ big rockets.
A decade before the Soviets and Americans were able to put anyone in space, experts predicted the harnessing nuclear energy would produce electricity in such abundance that it would be “too cheap to meter.” That hasn’t worked out yet, either.
I don’t think you can categorically say that there is “no” incentive to go [return] to the moon. In fact, I believe the opposite is true. Not only should there be incentive to return to the moon, but an accompanying, hard to contain, giddy excitement about the prospect of outdoing what has been done by making it further and further into space (ie. Mars). Growing up as a kid, it was all I thought about. I was a total Star Wars junkie and I wanted my own spaceship so that one day I could take my friends anywhere in the galaxy. It is a natural human desire to want to push the limits of our ability and this is surely Richard Branson’s motivation. The fact that people are willing to spend millions of dollars to ride in a glorified airplane is testiment to this.
It probably would be easier, safer, and less expensive, but not dramatically so. NASA’s cancelled Constellation program also came with an estimated $200 billion cost. That was for a set of moon landings, though it also included the development costs for new craft and rockets with significantly greater capabilities than Apollo. It seems that Constellation was going for easier, safer, and better (rather than cheaper).
Private aerospace companies have continued to develop launchers over the last several decades, but the improvements have been incremental.
Why then have these “really big rockets” not become reduced in cost - nary replaced with exponentially more capable, smaller, faster and more efficient propulsion systems in the nearly five decades since the first Apollo moon landing?
Same reasons why car engines, airplane engines, power plants etc. haven’t advanced “exponentially” in that time. There’s only so much energy stored in fuel, and efficiency is ultimately limited by the laws of thermodynamics. Advances in materials, design and manufacturing techniques allow you to get closer to that limit, but there’s no room for “exponential” advances.
So somehow we’ve made dramatic improvements and reduced the cost in almost all other areas of science and technology except rocket fuel and propulsion systems? And why spend billions of dollars? Why not just use the cheaper, more accessable 1960’s technology. It’s already been tried and tested and we know it works so why not re create the feat, if only for posterity?
Because there isn’t any market for rockets that big. Smaller rockets can be sold to the military (although the ICBM market has sunk like a lead brick since end of the Cold War) but nobody but altruistic space pioneers wishing to leave Earth orbit have any use for a rocket as powerful as a Saturn V. Business does not do R&D for products there is no market for and the typical American taxpayer doesn’t even want to fund basic things like health care or education, let alone trips to Mars.
Computing capability has improved in a roughly geometric progression, but there is no other aspect of technology applied to rockets or spacecraft that has progressed in anything like an “exponential advance.” Material thermal and erosive limits have improved incrementally, but those increments are getting smaller as successive advances nudge against the absolute physical limits of solid substances. Practical propulsion technology has achieved only very marginal improvements in efficiency, and the specific impulse that could possibly be achieved is limited by the absolute energy density of the propellants. Until we move beyond chemical propulsion, there are some hard limits about how big and efficient (from a mass propellant standpoint) we can ever make a launch vehicle. Our understanding of space physiology and advances in statistical risk assessment of launch vehicle subsystems has actually reduced the environments and hazards we can tolerate. The “Space Clipper” and interplanetary spacecraft presented in such a believable manner in 2001: A Space Odyssey turn out to be hopelessly optimistic and subject to capability limits that were not appreciated.
With all of that, we could still put people on the Moon with more reliable and probably cheaper technology, had we continued to evolve the highly successful Apollo program and Saturn family of rockets (although not on an “exponential” scale). Where we faltered was when Nixon limited the manned space program to Low Earth Orbit by mandating the Space Transportation System (Shuttle), a system designed by committee to go nowhere useful and not do anything in particular in getting there. We are now playing catchup to that blunder. Ultimately, though, we aren’t placing the same focus to go to the Moon because there is nothing in particular there that is useful from either a scientific or resource perspective. We are exploring other planets in the Solar System quite effectively, in ways that would not be feasible if we insisted on sending people along with the probes, which perform quite nicely without any obnoxious passengers interrupting a beautiful picture of Enceladus with an ill-timed urine dump.
I know that people like to claim mining of [sup]3[/sup]He as a profit incentive, but in fact we are still an estimated two decades away from achieving controlled D-D or D-T fusion (and have been for, oh, the last fifty years) and the D-[sup]3[/sup]He reaction is about two orders of magnitude more difficult than D-T reaction (per the triple product criteria, and even higher for the Lawson criteria) at the minimum temperature for a sustainable reaction, which is itself about half an order of magnitude higher. In other words, D-[sup]3[/sup]He fusion is way harder than the D-T reaction that we can currently not achieve, and has other issues that make its ultimate viability questionable with extrapolation of any existing technology despite the benefits of ostensible aneutronicity of the reaction. And even if [sup]3[/sup]He does become a useful fuel, it may very likely be more profitable to collect it in interstellar space or synthesize it by neutron bombardment than to attempt to extract it from lunar regolith. This is just not a good rationale for a manned Lunar mission or outpost.
Stranger
There’s lots of room for major advances in propulsion and fuel systems. Think of all the hidden military technology, zero point and cold fusion potential. It has been said there is black technology that is up to 100 years in advance of what we are currently being spoon fed. Dare to dream friend, dare to dream…
Oh yes, the hidden military technology and zero point energy. As you are so well informed in these areas, perhaps you can go develop your cold fusion powered anti-gravity spaceship and zip away to the nearest Galactic Hypermart to pick up a gallon of red mercury and maybe a couple of anti-mind control baseball caps. Thanks.
Stranger
Interesting how my desire for a spaceship to fly my friends around the galaxy gets a pass but I’m chastised for bringing up potential existing hidden technology. And you’re much too generous in your assertion of my being “well informed”, but thanks none the less for the compliment. As mentioned previously, dare to dream…
I think your key mistake is that you are overestimating how much technology has progressed since the 1960s.
With the big exception of information technology (and it is a big exception), most technological progress since then has been purely incremental - small improvements on existing designs. Aeroplanes and cars today work on the same principles as they did then, for example.
This is quite different to the first half of the 20th century, during which nearly every aspect of life was revolutionised.
Asking why launching stuff into orbit hasn’t got easier with fuel rockets is like asking why with the improvements in medical science, the worldwide death rate remains stubbornly at 100%.
pdts
Of course it was all Richard Nixon’s fault we haven’t gone beyond sub-orbital since the 1960’s. Why didn’t I think of that? An alternative explanation is that one of his numerous handlers gave him the Van Allen Belt Coles Notes and educated him on the prohibitive radiation dangers that existed beyond Low Earth Orbit. Just a theory.
Desire for a cheap, practical spaceship is perfectly logical: We’d all like such a craft. Believing that it (or similar technologies) already exists, and They are just keeping it from us, is not logical at all. If there were a Them that were doing such things, Stranger on a Train and I and several other people in this thread would all have to be part of Them, in which case why are you paying any attention to us at all?
We’re not, incidentally. If I had access to that kind of technology, I’d both be using it and bragging about it, and most other scientists are the same way.