Quote from: redliox on 04/11/2014 08:24 pmAgain guys, talk about the terrain or region that might work bestOr about the approach to take in finding the best terrain/region. I was impressed by the method Vanoutryve et al. used. See e.g."An Analysis of Illumination and Communication Conditions near the Lunar South Pole based on Kaguya data"http://solarsystem.nasa.gov/docs/pr404.pdf
Again guys, talk about the terrain or region that might work best
If you are having problems with shadows can we find an arrangement in which no more than half the solar panels are shaded at any time? We just need twice as many poles.
Quote from: A_M_Swallow on 04/12/2014 08:01 amIf you are having problems with shadows can we find an arrangement in which no more than half the solar panels are shaded at any time? We just need twice as many poles.A cylindrical surface would be constantly illuminated, no matter if the sun was in the south, east, north or west. But then the watts per square meter of array would fall by a factor of pi.Also when a given part of the surface swings between full sunlight and complete shadow, you once again have to deal with destructive temperature swings.But a cylinder would be more stable than a rotating mast.And I suppose the panels on the sunside could send heating electricity to the shadow side of a cylinder. Since they're insulated by perfect vacuum. the heating expense may not be high.
or any of a zillion components that might slowly or suddenly fail due to extreme temperature changes.
Talking about solar panel design and installation does no good until the fundamental question is answered: "how much continuous electrical power will be required to power the base"? Only then will anyone have any idea how large the array must be.One needs to know how large the array is before one can design its installation.
Quote from: KelvinZero on 04/13/2014 01:09 amor any of a zillion components that might slowly or suddenly fail due to extreme temperature changes.There are no real extreme temperature changes at the poles to speak of. The sun is at a pretty consistent angle of ~1.5 degrees for the entire lunar month, just constantly changing direction. The subsurface temperature, whether in sunlight or shadow, remains around -110 degrees C, more or less. Inside the permanently shadowed craters is a different story but on the average surface temperatures are fairly constant at the poles.
Quote from: clongton on 04/13/2014 01:25 amQuote from: KelvinZero on 04/13/2014 01:09 amor any of a zillion components that might slowly or suddenly fail due to extreme temperature changes.There are no real extreme temperature changes at the poles to speak of. The sun is at a pretty consistent angle of ~1.5 degrees for the entire lunar month, just constantly changing direction. The subsurface temperature, whether in sunlight or shadow, remains around -110 degrees C, more or less. Inside the permanently shadowed craters is a different story but on the average surface temperatures are fairly constant at the poles.Im pretty sure you would get extreme temperature changes, though the situation is better than at the equator. If there are permanently shadowed areas then I expect there are many more areas that are shadowed only half the month. I don't see why these should be much warmer than lunar night at the equator.
One of the reasons I was impressed by the Vanoutryve paper linked in a prior post was how they made "operationally actionable" thermal assumptions. In particular they assumed the thermal control system and batteries would support loitering through periods of darkness lasting up to 55 hours without sustaining damage.I Am Not A Thermal Engineer, but I have faith in modern thermal engineering design practices. As regards the "illuminated on one side; shadowed on the other" problem, I assume thermal engineers can design, build (and test) equipment that will meet reasonable requirements. Some amount of internal heat transfer is going to occur from the lit side to the dark side; clever design can maximize the usefulness of that. I'm not saying that design work will be easy or cheap; just that it will be valuable!
These lava caves look like a great place a base, there are hundreds to choose from. At up to 900m across it would be possible to land a Bigelow module in one then drive it inside.Some of the XPrize Landers in development could land in one and explorer it with a small rover.http://www.parabolicarc.com/2014/07/21/lunar-pits-shelter-future-explorers-settlers/