Why go to Moon?

[Duane534]

Seriously, why did we go to the Moon in the first place? To the best of our knowledge, it is just a giant hunk of rock, right? What can we do there that we can't do on the ISS?

[Quasi]

Well for starters, a launch pad. Yes, a launch from the ISS or similar station would cost less fuel by the actual space craft, but at the same time a certain amount of fuel would have to be spent by the launch station in order to counteract the spacecraft's launch in order to keep the launch station in it's original orbit.
The moon, while having a signifigant gravitational pull, would not require the net expenditure of fuel from a launch that a spaceborne pad would have.

Of course thats just my theory. Sorry if my assumption is a bit off, it's REALLY early here.....

[Duane534]

It's early here, too.

I guess that would be better.
*Has amusing mental picture of launching Saturn V off of ISS* Whoops!

[Duane534]

I know what you're thinking. I know that they wouldn't need as large a rocket as the Saturn V if they were already in orbit.

<font size=-1>[ This Message was edited by: Duane534 on 2002-11-09 03:53 ]</font>

[anu]

'Because it's there';
George Mallory (Everest 1924)

'Man must explore and this is exploration at its greatest';
Dave Scott (Hadley-Appenine 1971)

[David Hall]

There's no need to launch anything off of something else when in orbit. You just start your rockets and boost out of orbit. No affect on anything else at all. The space shuttle has launched several satellites, including the Hubble, in just this fashion.

Now, what do we need a Moon base for? Well, any research on the Moon itself to start. [img]/phpBB/images/smiles/icon_biggrin.gif[/img] Also, any activity that needs gravity would be easier to do on the Moon. The Moon itself can be a source of materials too. There may be water ice hidden at the poles, and other minerals could be mined from the soil. Radio telescopes built on the far side would be shielded from Earth's radio noise. Finally, you could build much larger structures on the Moon than generally possible in orbit. Orbiting platforms require lots of special materials and special designs, which must be launched up to orbit. If we could develop useful building techniques utilizing Moon rock and soil, we would not be limited to small sizes, and would have more room to work in.

[Quasi]

You're right, the launch station wouldn't need am equal amount of correcting thrust if the launch station had more mass than the spacecraft launching from it. The more mass the station has the less correction will be required.

Another factor to consider is how such corrections would be made. Each launch would be different I suppose, some launches could start the station spining, some could just push it left, right, or back, or it could be any combination of them. Imagine the calculations you would have to do after each launch in order to determine how to apply the thrust to put you back in proper orbit! Not to mention that you probably wouldn't have a whole lot of time in order to do this for fear of going too far out of orbit.

In summary, making a space-born launch area feasable (no dictionay handy, sorry) in my opinon would require:

1. a really fast computer to do those calculations for you AND apply proper counter-thrust.

or

2. Simply applying a minimal take-off boost on the part of the spacecraft until well clear of the station before opening up the throttle. Of course this is probably common sense unless your name is Kirk [img]/phpBB/images/smiles/icon_smile.gif[/img]



Anyhow, launching spacecraft will never be cost efficient until it is possible to mine raw materials, manufacture the proper materials from them, and assemble the craft from a place other than Earth and that has less gravity than the Earth. Don't forget, launching from space requires less fuel but getting the craft and/or materials to space (from Earth) requires the same amount it always has.

<font size=-1>[ This Message was edited by: Quasi on 2002-11-09 15:49 ]</font>

[David Hall]

On 2002-11-09 15:37, Quasi wrote:

Your right, the launch station wouldn't need am equal amount of correcting thrust if the launch station had more mass than the spacecraft launching from it. The more mass the station has the less correction will be required.

I think you still misunderstand. There's no need to apply any force to the station itself at all. You simply decouple your craft from it and use maneuvering thrusters until you're far enough away to use your main engines. There's no effect on the station at all, apart from a few minor mass balancing adjustments.

So, in effect, all launches would be similar to your number 2, above. But even easier.

[Superstring]

As David Hall said, the moon may harbor resourceful minerals and chemicals (ex water ice). Plus, we still have many unanswered questions on the moon itself, so maybe more in-depth studies of it would be needed by humans to go there.

Also, the Earth is getting too crowded. [img]/phpBB/images/smiles/icon_biggrin.gif[/img]

[Colt]

Here are some related links to threads in which we have been discussing this.

Lunar outpost question:http://www.badastronomy.com/phpBB/vi...683&forum=2&10

Colonization and space hotels: http://www.badastronomy.com/phpBB/vi...555&forum=2&42

What would we do today on the moon?: http://www.badastronomy.com/phpBB/vi...437&forum=3&40

Those are the main ones I can remember right now. -Colt

You're forgetting the most important thing: dust for the ion propulsion system. Any significant amount of dust would have to be accumulated on the moon, because it would be far too expensive to bring it from Earth.

[xriso]

If I get some rocket parts up into orbit, why would I want to put them back into another gravitational well?

[Colt]

Because there would be a base on the moon and orbit is sometimes a bad place to do things. It is easier to build a structure on the moon than it is in orbit. No decaying orbit, engine systems, and everything else that goes along with an orbiting structure. -Colt

[thkaufm]

Seriously, why did we go to the Moon in the first place?

Space travel is about more than just science experiments, it's about exploration. The moon is the natural first step in that exploration.

Tom

[nebularain]

On 2002-11-09 02:10, Duane534 wrote:
Seriously, why did we go to the Moon in the first place?

Why climb a mountain? Because it's there!

Seriously, humans are driven to know, to solve mysteries, to understand the things around them. Seeing a picture of the Grand Canyon is nothing like actually being there and experiencing it (I've been there; I know! It just makes your jaw drop!). We learned so much more from the guys being up there in person performing the studies and surveys than any probe could ever have done. More often than not in life, one finds that increasing one's knowledge of something, no matter how trivial, is never meaningless.

<font size=-1>[ This Message was edited by: nebularain on 2002-11-10 16:50 ]</font>

[jest]

Like David Hall said (and I was thinking it before I came across his message), if there were a rocket attached to the space station, all it would have to do is be released from docking clamps and simply coast away with perhaps a tiny maneuvre thrust or maybe even have the docking clamps set up with a motor to extend away from the station and then just as it stops, it opens the clamps and the "push" would be so minimal that it would sort of be like having something on your car seat and suddenly stopping, causing the inertial forces to let whatever's on that seat keep going.

But of course I agree with a moon base because of the vast possibilities of such a base, like general astronomy (NO atmosphere to worry about) using very wide array telescopes (it was mentionned that a radio telescope on the far side of the moon would be very efficient). Or somehow mining minerals that could be used for so many different things.

At first it does seem sort of pointless just going to the moon and walking around. But when you think about it, there's a lot that can be accomplished there. If they were able to assemble and launch probes for exploring the Solar system, the cost might eventually be less than it would be when launching from Earth. You wouldn't need a space shuttle or even a rocket - I figure the probe itself would probably be able to lift off with its own booster (correct me if I'm wrong of course) since the escape velocity is less there than it is here.

Imagine the possibilities of setting up greenhouses on the moon. Granted they wouldn't quite be the same as the ones we have here because of the cycles of the moon (two weeks of darkness). I don't know what effect that would have on a plant, though they ARE growing produce on the ISS as we speak so maybe they've got some ideas already.

Really, the moon is a great "launch pad" for human exploration of the Solar system.

[Colt]

^ *cheers* You could light the green house for the duration of the "dark time" with giant light arrays powered by you friendly nuke (buried a safe distance away of course).

Another thing that you could build since the escape velocity of the moon is less than 1/6th that of earth's (no air resistance, lower velocity needed) is an electromagnetic launcher. Either a railgun or coilgun would work. It could launch payloads into Lunar orbit where they could be picked up by a ferry and taken back to Earth (or to a space station orbiting the moon, what an interesting thought..). Right now NASA is developing an electromagnetic launcher that would be built inside of a mountain to launch shuttles along (think of a maglev rail but pointed up into the air). Here is a good article about it http://www.cnn.com/2002/TECH/space/0...glev.launches/.

Thing about what a coil gun is.
http://lifesci3.arc.nasa.gov/SpaceSe...ki/SPBI112.HTM

-Colt

[akualele]

And for anyone who likes good o' fashioned Sci-fi, feel free to read (or re-read):
The Moon is a Harsh Mistress by Robert Heinlein, and
Bouncing off the Moon by David Gerrold. Actually, this one is the middle book in a projected trilogy. I've already read the first 2 (#1, Jumping off the Planet, is about beanstalk theory) and they are pretty good.

[RafaelAustin]

I thought I remember reading recently that a popular proposal for the location of a moon base would be a crater at the south pole of the moon. At the center of this crater is a large hill, from the top of which you can see the sun all month long. The idea is to cover the hill with solar panels that would provide power continuously. Also I guess you could mount some rotating, sun tracking mirrors to light hydroponic gardens below.

Does anybody remember the name of this site and any facts about it?

[Espritch]

I thought I remember reading recently that a popular proposal for the location of a moon base would be a crater at the south pole of the moon.

That would also have the advantage of placing it near the most likely site for finding water on the moon (ice in polar craters where it would be shielded from direct sunlight by the crater walls).

[David Hall]

SF Moon stories from any of the Greats are perfect for envisioning lunar bases and societies. Heinlein is probably the best, with some of Clarke's longer stories coming in second. The Larry Niven short story The Patchwork Girlis another good one.

[n810]

On 2002-11-11 19:28, David Hall wrote:
SF Moon stories from any of the Greats are perfect for envisioning lunar bases and societies. Heinlein is probably the best, with some of Clarke's longer stories coming in second. The Larry Niven short story The Patchwork Girlis another good one.

I just hope that when the moon declares independance from the FN (Moon is a Harsh Mistress) I'm nowhere near where the rocks are falling. Of course if they start using the moon as a prison colony, I might becaome a habituall shoplifter so I can catch a free ride.

[RafaelAustin]

I thought I remember reading recently that a popular proposal for the location of a moon base would be a crater at the south pole of the moon.

After a little looking around...
Shackleton Crater

Site A is on the rim of Shackleton crater, and B is about six miles away on a ridge originating from that rim. Site C is on the rim of another nearby crater.
During the Moon’s 708-hour day, A is in sunlight 80 percent of the time, B is lighted 70 percent of the time and C about 65 percent of the time.
“There is only a period of 10 hours when neither A nor B are in sunlight,” the researchers added. “Therefore if solar arrays were placed in both areas and connected by a link (either microwave or cable) then a base at either site would receive near constant solar energy.”
The temperature at the suggested sites is relatively constant because of the steady light and was estimated at about minus-64 degrees Fahrenheit. Engineers say it is easier to deal with a constant extreme temperature than one that is changing regularly, as would happen elsewhere on the moon with the regular changes from daylight to darkness.

[Colt]

Can someone point me toward some books by Clarke about a Lunar base, or anything like that? I am sure he has written something like it but can't remember. Thanks. -Colt

[David Hall]

The one I know best by Clarke about the Moon is A Fall of Moondust. I also vaguely remember a story by him about some kind of observatory on the Moon involving spies or something and culminating in a big battle on the lunar surface, but I don't remember the title of that one at all. A few of his short stories might fit the bill as well, but I haven't read any yet that go into any details. Actually, it's been a long time since I've read much of him, so I don't have clear recollections at all.

As I said before, Heinlein is the best for Lunar stories. He wrote several novels and numerous short stories with lunar settings.

[David Hall]

One problem with a base at the lunar south pole would be getting there. It's more difficult to arrange a landing at the poles than closer to the equator due to orbital mechanics. You'd have to change from a relatively "flat" orbit to a polar orbit before you could attempt a landing.

Though I wonder how difficult it would be to insert your craft into a polar orbit from a trans-Earth trajectory directly. Is it possible to send your craft on a trajectory that naturally passes over one of the lunar poles, and thus easily enter polar orbit?

[kucharek]

I recently recognized that, AFAIK, StarTrek ignores the Moon completely. I guess for two reasons:
-with all this sophisticated propulsion and transporting stuff, there's no need for it
-the Moon would be the only place where the audience would expect these guys to walk in a different gravity than one g, thus requiring expensive FX (though Moon 1999 and U.F.O. never gave a damn about 1/6th g inside their lunar bases...)

Harald

[VanBurenVandal]

It also seems that a Lunar Base would be the best available testing ground for a future bases in other places (i.e. Mars). While discovering a design flaw on the Moon would be *understatement* bad, it’s a whole lot better than running into problems while on the other side of the Sun!

[Colt]

In Star Trek Luna has been terraformed and people live on it. They don't go to Terra that much either. [img]/phpBB/images/smiles/icon_smile.gif[/img] -Colt

[GrapesOfWrath]

On 2002-11-14 02:39, Colt wrote:
In Star Trek Luna has been terraformed and people live on it. They don't go to Terra that much either.

Like in Heinlein's Moon Is A Harsh Mistress, moon inhabitants might not handle Earth gravity. Susan Helms spent almost 200 days up there, how's she doing?