Uh...
"Metal oxide particles of the correct size would be sifted from the dirt and heated with hydrogen"
So where do they source the hydrogen from then?
American boffins say they have developed a viable process for making oxygen out of moon dirt, which could allow humans to live for long periods in lunar bases. The new tech has been tried out under the equivalent of the moon's one-sixth-G gravity aboard NASA's famous "vomit comet" low-gee simulator plane. A long-term moonbase …
They can create Oxygen on the moon by first using an industrial process to create water and then electrolyzing it. Then they will use this Oxygen as part of a fuel to gain energy. But surely *far* more energy is being wasted in producing it than it could possibly produce? Couldn't they find a more direct method to use the energy they have, rather than recreating the rocket technology that works here on Earth where Oxygen is relatively plentiful?
Apparently there is hydrogen at the poles:
http://www.latimes.com/news/nationworld/nation/la-sci-moon18-2009sep18,0,3019406.story
And in response to Peet & Lewis, as far as I know, plasma drives exist, but are only good for interstellar travel, as opposed to lift-off. They produce only very small amounts of propulsion, but can do so for a very long time.
The reason you would want oxygen and hydrogen would be for a conventional rocket to get you off the moon in the first place.
Yup, synthesizing fuel is incredibly wasteful from a thermodynamics point of view. If you have any alternatives, by all means, contact NASA about them.
Before doing so, though, please do remember that helicopters and planes don't work in a vacuum, ion engines don't generate anywhere close to enough thrust to escape even a weak gravity well, railguns would need to impart more than enough acceleration to kill the crew, and building a space elevator on the Moon would be excessively costly. When you say "a more direct method to use the energy", are you thinking of antigravity, or perhaps levitation?
"How MUCH oxygen/ice is actually there and how long will it last us if we are simply (as appears to be the plan) strip-mining it?"
The idea of using mined oxygen for breathing, rather than, say. hydroponic plant CO2 <--> O2 conversion, with chemical "oxygen generators" and/or mined oxy as emergency backups sound mire like more the way to go, to me. It might even be possible, with lunar soil as additional chemical feedstock for the plants, to generate excess O2 to be fed into the water/rocket oxidizer/reaction mass system while -- again -- keeping the Ice-Mines of Luna as emergency reserves.
As Kryten might have said:
"An excellent plan sir, with just two minor problems. First, where's all that hydrogen going to come from, and second, where do you get all that hydrogen? I know that technically that's only *one* problem, but it's such a biggy I thought it worth mentioning twice."
Headline should have read: "So-Called "Scientists" Miss Point, Waste Millions. Again".
Maybe they can get the hydrogen by splitting up the water the other bunch claim to have found earlier this week. But then, you wouldn't need to cook moondirt in the first place.
There still needs to be more work done. This is still too preliminary. Large deposits of hydrogen or water need to be established for a permanent base otherwise there's no point. If your going to build a base, you have to consider the LONG term uses, not just Mars. You have the moons of Jupiter and the asteroid belt to consider also. The moon needs to be a replacement for space stations. Something that will last, unlike the ISS, which is scheduled to be scuttled in 2014.
Yesterday it was either water (and)/or hydroxyl - today it's water for sure. What happened? Did the L. Reg playmobile preconstruction work so well sifting bits of sand about the office table that it was a pity not to write up the story? Or is this a deeply savage and ironic critique on the entailed lunacy in the application and limitations of models, real and virtual?
Bang on. What is this constant need to use the moon as a base? Creating bases at the L-Point makes far more sense. We currently know of no planet in our system capable of supporting life. At least with a space station you do not have the problem of slowing it down before it hits the surface too hard, and you do not have the problem of having to use large amounts of energy getting back off it.
Ion / Plasma drives are likely to be our best tool for long distance travel, and starting them from a space station makes far more sense. What makes even more sense is to try and make use of ideas like the Mars Cycler idea by Buzz Aldrin. We need to use gravity like sailors use the wind.
Gentlemen.
It would seem that hydrogen is not a particularly big problem. The abstract available here: http://adsabs.harvard.edu/abs/1988lhfp.rept..115G (just google for "lunar hydrogen") seems to indicate that by simply heating regolith, sufficient quantities of hydrogen can be obtained.
The problem these scientists were working on was getting oxygen from moon rock. If hydrogen was already a solved problem, there's no need to re-iterate the solution.
Wipe the rabid foam from your lips and move on.
Hydrogen source:
The article does not mention hydrogen, true. In order to produce energy, you need H2 to form H2O, but the molecular masses of both elements are vastly different: 1 for H and 16 for O - a 2:16 relationship in a H2O molecule. So for each kg of H2 you need 8kg of O2. Even if you still need to bring H2 from Earth, you now need to bring only 1/9th of the mass needed before - a wast improvement methinks.
Railgun:
Moon escape velocity is 2380 m/s. Maximum acceleration during ascent for Apollo missions was 4G. At 4G constant acceleration (for about 61s), the railgun would have to be 72.25 km long. Not sure how many people can survive 4G for a minute, but 2G should be OK for most: at 2G: 144.5 km length, 122s of acceleration.
100 km or so is a huge linear motor, but not impossible to build I think.
They did put a man on the moon 40 years ago with 1960's technology...
Perhaps, but what angle would it need to be aimed at? Building a 100km plus accelerator becomes a lot more difficult if you've got to point it skyward rather than building it flat.
Producing fuel has value in itself, even with a nuke plant on the moon that power isn't really that transportable. In theory you could get it from other sources that have ice though, perhaps the asteroids might have some somewhere? Long term somehting else would be better to find, but as has already been mentioned only chemical rockets can currently lift something off a body. Even if we don't go to the moon but go other places instead we will have to get our craft off those bodies somehow.
Even if there is an alternitive to fuel for the moon, if a lunar base is supposed to expand and be sustainable without outside help, being able to produce oxygen is going to be useful. Esp. while the CO2 levels are getting up to the point where plants can reliably recycle the air for human consumption, and also to replace any oxygen that is lost due to accidents. Then there's the whole thing of being able to produce water without having to mine it.