Location of Moon Base - Discuss.

[centsworth_II]

<font color="yellow">"...the polar regions would be inefficient for either domed agriculture or solar arrays. Think about it. At that low angle, the density of sunlight would be far less than at the equator. In addition... half of the time the solar arrays (or domes) would be in the shadow of the rest." -- Mental_Avenger</font><br /><br />Wouldn't a solar array standing vertically at the pole gather as much solar energy as it would laying flat at the equator? I'm sure the arrays could be engineered so as to limit their shadowing each other. At least the problem is not unsolvable as the problem of eliminating night at the equator is. <div class="Discussion_UserSignature"> </div>

 

[quasar2]

it seems to be generally known that Lunar Orbit is at lower altitude at the poles. therefore it stands to reason less fuel would be needed to achieve Lunar Orbit. <div class="Discussion_UserSignature"> </div>

 

[mental_avenger]

<font color="yellow"> it seems to be generally known that Lunar Orbit is at lower altitude at the poles. therefore it stands to reason less fuel would be needed to achieve Lunar Orbit. </font><br /><br />I still have no idea what you are talking about. An orbit can be made circular or elliptical, as needed for the assignment. In the case of the Lunar Prospector, they refer to a Low Polar Orbit. That merely refers to the fact that the orbit crosses over the poles, and is relatively close to the surface. It started out at about 100km, and later was adjusted to various altitudes for closer observation. However, AFAIK, all the orbits were circular orbits.<br /><br />From the Lunar Prospector site: <i>”The data collection will be periodically interrupted during the mission for orbital maintenance burns, which will take place to recircularize the orbit whenever the periselene or aposelene is more than 20 to 25 km from the 100 km nominal orbit, about once a month.”</i><br /><br />Now, again I ask, what do you mean by the “Lunar Orbit” is at a lower altitude over the poles, and how can that possible relate to any fuel savings for a spacecraft launched from the surface?<br /> <div class="Discussion_UserSignature"> <p style="margin-top:0in;margin-left:0in;margin-right:0in" class="MsoNormal"><font face="Times New Roman" size="2" color="#ff0000"><strong>Our Solar System must be passing through a Non Sequitur area of space.</strong></font></p> </div>

 

[mental_avenger]

<font color="yellow"> It's really a question of how tall you want to build them. </font><br /><br />There is a practical limit to how tall you can make them, and no matter how you arrange the towers, they will shadow each other. No way around that.<br /><br /><font color="yellow"> is the idea of mining space so that we don't have to tear up our own planet to get the things our technological society needs. </font><br /><br />If you are referring to mining the Moon for materials to build spacecraft and space stations, it will be a long time and an incredibly expensive infrastructure before that happens. If you are talking about importing materials from the Moon to be used on Earth, that would be many many times more expensive than ANY mining on Earth, so will never be practical. If you are talking about mining asteroids for anything, it will be a looooooong time before that can ever be a break even venture, let alone profitable.<br /> <div class="Discussion_UserSignature"> <p style="margin-top:0in;margin-left:0in;margin-right:0in" class="MsoNormal"><font face="Times New Roman" size="2" color="#ff0000"><strong>Our Solar System must be passing through a Non Sequitur area of space.</strong></font></p> </div>

 

[nacnud]

The solar panels will shadow each other but that is not a show stopper. Remember they will probably be used as a low mass power solution until a nuclear plant can be built.

 

[centsworth_II]

<font color="yellow">"...no matter how you arrange the towers, they will shadow each other. No way around that."</font><br /><br /><br />One way around it would be to have only one tower, large enough for the power needs, which rotates to face the sun. No other towers, so none in shadow.<br /><br />Even if you have an arrangement of towers so that at any one time some are in shadow, that would be a good time to perform maintenance. In any case, there would always be some panels in sunlight. <br /><br />I see a two week night at the equator as a much greater solar energy problem to overcome than shadowing at the poles.<br /> <div class="Discussion_UserSignature"> </div>

 

[mental_avenger]

Reality check. Here on Earth, away from the poles, solar power is only available half the time. On the Moon, away from the poles, solar power is only available half the time. Half a 24 hour period, half a 30 day period, no real difference. Clearly, building large, flat solar arrays across the surface is a lot easier than building towers. Towers would require the solar arrays PLUS the tower material. Also, the tower would require all the machinery to keep it aimed at the Sun, lots more to break down, not to mention the power they would consume.<br /><br />The point is, it would be counter-productive to choose a site simply because of continuous solar power. Nuclear power will take up the slack, virtually from the beginning anyhow.<br /> <div class="Discussion_UserSignature"> <p style="margin-top:0in;margin-left:0in;margin-right:0in" class="MsoNormal"><font face="Times New Roman" size="2" color="#ff0000"><strong>Our Solar System must be passing through a Non Sequitur area of space.</strong></font></p> </div>

 

[alokmohan]

Is there any expected date when we perform this wonderful feat?

 

[SpaceKiwi]

I could be facetious and suggest Johnny Mathis sung the answer to your question, alokmohan, but first things first. We need a manned rocketship that goes somewhere other than LEO.<br /><br />Good to see you around these parts again. <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[spacester]

I agree with you for the most part mental, but a) from an engineering standpoint there is a big difference between 12 hours and two weeks and b) the timing of the nuclear power deployment can not be counted on being early in the development.<br /><br />I agree that the power tower is suspect on mass requirements. I agree that the site should not be chosen on the basis of continuous solar power.<br /><br />IMO our lunar encampments should provide access to the entire globe. There should be two bases on the near side, one on the "right-hand side" as you look at the moon from Earth, and one on the left. They each would have a spectacular view of Earth low in the sky. You could extend the daytime stay for a given group of humans by transferring them from the first to the second before it gets dark. There should be a third base on the far side, site chosen for radio astronomy purposes but in a place that can be accessed from the second base, so that lunans can stay in the sun fulltime if they have the transportation to do so.<br /><br />The resources for these bases would come from one of the poles, where our first and most important base would be. <br /><br />Keep the industry at the poles, the people near the equator, the scientists everywhere especially the farside, keep everybody happy. <img src="/images/icons/laugh.gif" /><br /><br />The polar base would produce water and LOX at a minimum. If we put a nuke power plant there, maybe we can microwave or laser beam energy to the bases and keep the nukes at the poles. Since you're going to need a fleet of trucks with big tanks to get those liquids to the bases, maybe you truck hydrogen to the bases as well, or instead.<br /><br />Of course it would be better to have the nukes at the bases themselves, I'm just saying that the political difficulties may dictate that we use a lot of solar to get things started before we get the broadspread support needed to be flying multiple nukes. Early on, truck the energy from the poles to the base <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<font color="yellow">"Keep the industry at the poles..."</font><br /><br />Good plan and, if there is substantial water at the pole, unavoidable. I came to this discussion late. What is the big attraction to living at the equator as opposed to the pole? Is it just a fear of one solar panel casting a shadow on another? <div class="Discussion_UserSignature"> </div>

 

[najab]

><i>The point is, it would be counter-productive to choose a site simply because of continuous solar power.</i><p>There are basically three ways to die in space: lack of power, lack of air, lack of food/water. Guess which will kill you the fastest.</p>

 

[mental_avenger]

<font color="yellow"> I agree with you for the most part mental, but a) from an engineering standpoint there is a big difference between 12 hours and two weeks </font><br /><br />Agreed. However, if bases are limited to the poles, there will be very few bases and therefore few people on the Moon. That, of course, goes along with my prediction of what part the Moon will actually play in space.<br /><br /><font color="yellow"> the timing of the nuclear power deployment can not be counted on being early in the development. </font><br /><br />I don’t see that as a big obstacle. So far, most objections have been about having a nuclear power source in orbit around the Earth. If it was being shipped directly to the Moon (or Mars) I don’t see those objections as being a problem.<br /><br /><font color="yellow"> They each would have a spectacular view of Earth low in the sky. You could extend the daytime stay for a given group of humans by transferring them from the first to the second before it gets dark. </font><br /><br />This is (apparently) making a huge assumption that the Moon would be used for tourism. I seriously doubt that tourism will ever be more than a very very few persons per year at best, and not for a long while. In addition, there is a big disadvantage to daylight bases. For two weeks, the surface of the Moon will be bathed in extra radiation from the Sun as well as requiring bulky heat dissipation suits. Heating suits is far easier than cooling them in space.<br /><br /><font color="yellow"> The resources for these bases would come from one of the poles, where our first and most important base would be. </font><br /><br />Getting power (or anything else) from the poles to the equator of the Moon would require transporting that resource 1700 miles. This is not a trivial task, and there has to be a lot of need before that kind of infrastructure can be justified.<br /><br />You can’t beam water 1700 miles (assuming that th <div class="Discussion_UserSignature"> <p style="margin-top:0in;margin-left:0in;margin-right:0in" class="MsoNormal"><font face="Times New Roman" size="2" color="#ff0000"><strong>Our Solar System must be passing through a Non Sequitur area of space.</strong></font></p> </div>

 

[j_crockett]

<br />If they find water at the poles then the poles are a great idea. <br /><br />I don't believe that 24 hr sunlight is a good enough reason for site selection by itself. As a geologist, I would want to be closer to places that I wanted to study. There is are a lot of factors that go into site selection, and we have excellent data on six sites. I find it puzzling that we would ignore all six and pick a site because it is a good place to have solar panels. <br /><br />By the way, if the sit was on the equator near the center of the moon, in the middle of the night there would be a full earth. Does anyone know how much light that would give off, and would it run the solar panels.

 

[quasar2]

perhaps i`m wording this wrong. & i can`t remember whether this orbit was elliptical or circular. but we`ve had several threads on this. therefore they`re buried. & actually i didn`t originally come up w/ idea. i seem to recall someone saying the orbit would almost touch the top of the So. Polar Mtns. i`m huntin them up though. this is too complicated of a statement for the searchbox, so that avenue is difficult. since this had been mentioned several times i felt safe to repeat it. <div class="Discussion_UserSignature"> </div>

 

[quasar2]

my main priority for near-side landing would be inspection of the old equipment. there are good arguments on both sides of this. bombardment & radition may have rendered it useless. the alloys used @ the time are incompatible w/ a MoonReturn`s. the latter being a valid point, what about raw ores we`d mine? would this not be in a sense incompatible? these would hafta be blended (is that correct term?), while if we melted & recycled whatever old equipment wouldn`t that be easier than raw? & if it`s in compatible why couldn`t we simply use end products as stand-alones? like use them as something simple like a shovel? & if we did make a trip between nearside & a pole consider this. wouldn`t there be one or more old sites in between? of course there would be a question of melting & recycling the old equipment in a "fast" way. we do have that capability now: google on Mobile Parts Hospital. <div class="Discussion_UserSignature"> </div>

 

[mental_avenger]

Any orbit can be elliptical. Without an atmosphere, the orbit can come within a few feet of the surface (although that wouldn’t be wise) in polar orbit, equatorial orbit, or anywhere in between. I don’t know any restrictions on one vs the other. The real problem is not getting up to orbital altitude, but up to orbital velocity (somewhere between 3300 ft/sec and 5500 ft/sec). Also, remember that after you attain orbit, you will then have to leave that orbit to head back to Earth, so an equatorial orbit would be more efficient. <div class="Discussion_UserSignature"> <p style="margin-top:0in;margin-left:0in;margin-right:0in" class="MsoNormal"><font face="Times New Roman" size="2" color="#ff0000"><strong>Our Solar System must be passing through a Non Sequitur area of space.</strong></font></p> </div>

 

[henryhallam]

<font color="yellow"><br />Also, remember that after you attain orbit, you will then have to leave that orbit to head back to Earth, so an equatorial orbit would be more efficient.<br /></font><br /><br />A polar orbit isn't necessarily less efficient for trans-Earth injection, BUT I'm pretty sure you can only execute TEI from a polar orbit twice a month without an expensive plane change, compared to a near-equatorial orbit where you get a window every orbit. However that isn't too big a deal for a surface launch, because you can launch into the specific polar orbit that's appropriate for that time of the month. It only becomes an issue if you want to do an Apollo-style lunar orbit rendezvous - here you would have to land and then have either a very short stay or one that is a multiple of 15 days.<br /><br />I think the intention for the VSE is to use a direct-ascent mission mode as this makes sense for longer stays and larger cargoes anyway.