New Radar Maps of Moon

SpaceAdmiral writes to mention that NASA has some new high-resolution radar maps of the Moon obtained by the Jet Propulsion Laboratory. The new images have also been used to create a simulation of the Moon's day and a movie of a Moon landing from the point of view of the astronaut. "NASA is eying the Moon's south polar region as a possible site for future outposts. The location has many advantages; for one thing, there is evidence of water frozen in deep dark south polar craters. Water can be split into oxygen to breathe and hydrogen to burn as rocket fuel--or astronauts could simply drink it. Planners are also looking for 'peaks of eternal light.' Tall polar mountains where the sun never sets might be a good place for a solar power station."

Re:Err.. Why do we need H20 for fuel again when,

[Wandering Wombat]

Because there's no way in Hell you're getting OFF the moon with ion drives. 1/6th gravity is still way, way more attractive force than an ion drive is capable of generating. But yeah, once you're back in (relatively) zero-gravity space, toodle around in your ion drives all you want.

Re:H2O - H2 + O2

[evanbd]

LOX/LH2 rockets are normally run fuel-rich (most rockets are, actually, it's just more pronounced with LH2). 2H2 + O2 corresponds to a mass ratio of 8 parts O2 to 1 part H2; in actual practice the mass ratio used is somewhere between 4:1 and 6:1, depending on the engine.

There are several reasons for this. One is that the chemistry going on is more equilibrium chemistry than normal combustion chemistry -- the H2, O2, H2O, OH, etc are all in equilibrium. Adding excess H2 burns more of the O2, and that gets more energy out of the reactants per unit mass (having similar numbers of moles of unburned reactants uses less weight if they're moles of H2 instead of O2). Secondly, H2 is better behaved than almost anything else when it comes to using the nozzle to turn heat into kinetic energy -- you'll get a larger fraction of the chemical energy out as exhaust velocity. If the H2 were inert, that wouldn't be enough to make it worth adding, but it's not inert as explained above. And thirdly, adding excess H2 drops the combustion temperature while simultaneously increasing the cooling ability (LH2 is a marvelous coolant; LOX isn't), making it easier to run the regeneratively cooled engine.

Re:We got your Peaks of Eternal Light, right here!

[Anonymous Coward]

Shouldn't there be a term for doing this whenever a discussion about the moon comes up, similar to Godwinning? Either way, well played sir!

Not exactly applicable for Slashdot and lunar threads, but there's a move to use Bostowned [urbandictionary.com] for whenever the cops freak out over something mundane and then trump up bogus charges against the victim in order to save face.

Doesn't have to happen in Boston; it can happen anywhere. (Like these hashers [msn.com] who used flour to mark a temporary trail through the woods for an afternoon's run, whereupon the paranoid fucktards who run the city of New Haven bost0wn3d themselves, and tried to cover up their stupidity by arresting the runners on bioterror charges and threatening to sue them in civil court.)

Re:H2O - H2 + O2

[wizardforce]

They've been doing this for years. some of the oxygen is used to oxidize the hydrogen and some of it is used to breathe. In this case, you would probably be using the hydrogen/oxygen to power fuel cells during the night time as solar power is available to regenerate the oxygen and hydrogen stores during the day. It's probably not going to be used as the only power source sue to the fact you would need to carry all of it up there from Earth at an expense hovering around 10,000$ a kg. More likely is that it will serve like a battery storing power for emergencies and night-time.

Re:Use of solar energy

[vajaradakini]

Of course solar energy isn't going to work if you're sending probes out of the solar system, you sort of start to run out of sunlight after a while.

However, when it comes to a lunar base, solar power (if available all the time) would probably be better than hauling uranium up from the earth or having to search for and mine some on the moon (I'm not sure how much uranium there would be on the moon either, since it's less dense than the earth and probably contains fewer heavy elements).

Re:Use of solar energy

[Anonymous Coward]

solar panels are much better this close into the sun. pioneer (and voyager, galileo, cassini, new horizons, etc) needed thermoelectric generators because the sunlight is too weak out beyond the orbit of Mars.