Who said the OP was talking about multiple launches to mars?
Um, it looks to me like you did. I'm not talking about Mars specifically, although Mars is definitely "elsewhere". I suggest that the asteroid belt would be a pretty good place to check out.
They only claimed that one flight from the moon could support multiple flights (of some type) from the moon. It is just as reasonable to assume they were talking about orbital flights from the respective bodies.
OK, one massive massive massive flight of fuel to the moon would indeed support many moon-to-lunar-orbit flights. So what? There's nothing of particular interest on the moon, and even less in Lunar orbit. Is there interesting stuff to do on the moon? Sure. Heavy industry ain't it.
Given that, the formulation you hint at neglects the reusability of a moon-based spacecraft.
Yes it does, since we don't have good examples of such objects. In the future, things will indeed be different.
That's a big issue on the moon, as the ratio of the mass of the spacecraft to the mass of fuel required to reach orbit is vastly different from earth (I'm sure you know this, but others may need to be reminded).
*eyebrow* Yeah. The obviosity is pretty staggering.
So, assuming a long-term reusable spacecraft has been landed on the moon (we'd only need to do that once), you're betting that launching the equivalent weight in fuel and landing it on the moon is not enough to reach lunar orbit more than once. If you had enough fuel to do any more than that, say 1.1 launches, then the OP is correct.
But, again, WHO CARES about lunar orbit? I was indeed assuming that we wanted to go to interesting places in the Solar System. If we want to go somewhere boring, it's a lot cheaper to go to my home town.
Now, I don't know the actual answer, but I bet its a lot closer than if you simply treat the moon as one-time detour for a spacecraft on its way somewhere else. If you aren't returning to the moon, it obviously doesn't make sense to stop there as you point out.
Again: I contend that the moon is not a useful place to go. There are indeed good scientific reasons to go to the moon, but no industrial, economic, or exploratory ones. I'm certainly not discounting the value of the science, but I don't think it's the most important objective. (It's also one of the less expensive objectives, which is cool indeed.)
Until we build a base there, we can't put a spacefaring industry there. That's why its so important to look for ways to use the moon's resources, and put it to the test with a "useless" (for now anyway) moon base.
What resources are those? Yes, fine, HE3. Get back to me when we've got a reliable fusion reactor.
There's also the issue of figuring out how to live in space for long periods.
That problem is well understood.
A 2-year mars mission would be suicide unless we'd built up and tested our systems on an easier problem (a moon base would be perfect for this).
I think that's a silly contention. Risky? Yes. Most valuable enterprises are. Suicidal? Come on.
After all, there's a reason we had the Mercury and Gemini programs before Apollo. We didn't just build the moon mission from scratch.
But, having built the moon mission, building another moon mission is not useful. We've learned those lessons. Time to take the next step.
Just a hint: The delta vee to take off from earth, land on the moon, take off from the moon, and go elsewhere in the solar system is rather higher than the delta vee to just take off from earth and go elsewhere in the solar system.
Until there's spacefaring industry on the moon itself (working with indigenous resources), the moon is not a useful space base.
There's an argument to be made for on-orbit assembly, but I think not a terribly strong one. Systems integration is hard, and doing things in orbit is really hard.
"The Case for Mars" by Robert Zubrin talks about this in some detail. Good book.
Yeah, I've totally lost the thread of your argument.
My Treo 650 is a fine phone, a great PDA, and a very acceptable portable web/email device. It's not perfect, but it works fine.
So, again: Well designed devices are good. Poorly designed devices are bad. Whether a device is "converged" or not does not locate it on the wellpoorly designed axis.
I don't know...I like being able to get up-to-the-minute bus schedules on a device I carry in my pocket.
I don't care if my phone has a web browser, or a game of Snake, or a camera...as long as those don't detract from its utility. In my experience, they do not.
You mentioned a swiss army knife, and conveniently ignored my Leatherman comment. Swiss Army knives are pretty lousy at a lot of tasks. My Leatherman is surprisingly good at a fair number of tasks.
Badly designed "converged" devices are bad. There's no argument there.
Why is it that just about every missive I've ever read about how people never use multi-function devices was generated on the most powerful multi-function device in history?
I like my Leatherman. I like my Treo 650. I like my various personal computers. Well designed "converged" devices mean that I can schlep less stuff, and that's good.
In my stereo cabinet, the convergence argument is definitely a more open issue. However, I haven't had a dedicated CD player in my stack for ten years.
Deceleration? Whaaaa? You were reading bad 60's comic books, weren't you?
If you're travelling fast enough to light a scramjet, slowing down is EASY.
Thing about "pointing in the right direction"...when you're targeting things that move, the "right direction" changes while your weapon is in flight. Hence, "guided missile".
A ballistic weapon is great against point defenses, and short-range targets. Not so much for naval battles.
Um, you understand that there's a non-trivial amount of R&D that will need to happen between the fired-straight-at-the-ground test article, and a missile that can actually maneuver at the end of its flight and not disintegrate, don't you?
I sure hope so, because it sounds an awful lot like you're talking out your ass.
"Is our collective time really that valuable that we can't relax and enjoy a journey?"
I've got no idea who speaks for the value of "our collective time", sometimes getting somewhere quickly is nice. Do you seriously spend time thinking about things like that?
If I want to visit Australia, and I have two weeks' vacation, I'd like to get there in a reasonably short amount of time. Two weeks on the open ocean doesn't sound like a heck of a lot of fun.
Having said that, changing an eighteen hour flight (incl. time in the terminal) into a ten hour flight (incl. time in the terminal) doesn't necessarily simplify my logistics.
Having said that, the reason we have free markets is so that people whose value assignments differ from mine can spend money to get things that aren't necessarily valuable to me. Shocking, wot?
The requirements for moving humans are very different from moving bulk cargo, so I'm not sure that the efficiency calculation is quite as simple as you're making out.
People are pretty light weight for the amount of volume they require to be comfortable. Bringing 175 lbs of crude oil NY to Paris in 12 hours isn't very useful. Bringing a couple bazillion barrels in a couple of weeks is pretty darn useful.
(especially when you load the supertanker up onto big logs and roll it from the coast to Paris. That's the really efficient part.)
I don't have the numbers close to hand, but 747s at cruise are pretty darn efficient.
Um, so on relatively long international flights (you know, like ones that go across big oceans), the time spent in the terminal is not as great as the time you spend in the air?
Like, I dunno, NY to Paris, or LA to Tokyo? Flights that take 12-18 hours? Am I ringing any bells here?
Yes, we're spending longer than ever in terminals, but I've got more faith in engineers making fast jets than in bureaucrats making meaningful and efficient security processes.
Content Restriction Annullment would be a good thing. Protection of good things is often interpreted to be good. Your sig is not much with the sense-making.
Slashdot Mirror
Who said the OP was talking about multiple launches to mars?
Um, it looks to me like you did. I'm not talking about Mars specifically, although Mars is definitely "elsewhere". I suggest that the asteroid belt would be a pretty good place to check out.
They only claimed that one flight from the moon could support multiple flights (of some type) from the moon. It is just as reasonable to assume they were talking about orbital flights from the respective bodies.
OK, one massive massive massive flight of fuel to the moon would indeed support many moon-to-lunar-orbit flights. So what? There's nothing of particular interest on the moon, and even less in Lunar orbit. Is there interesting stuff to do on the moon? Sure. Heavy industry ain't it.
Given that, the formulation you hint at neglects the reusability of a moon-based spacecraft.
Yes it does, since we don't have good examples of such objects. In the future, things will indeed be different.
That's a big issue on the moon, as the ratio of the mass of the spacecraft to the mass of fuel required to reach orbit is vastly different from earth (I'm sure you know this, but others may need to be reminded).
*eyebrow* Yeah. The obviosity is pretty staggering.
So, assuming a long-term reusable spacecraft has been landed on the moon (we'd only need to do that once), you're betting that launching the equivalent weight in fuel and landing it on the moon is not enough to reach lunar orbit more than once. If you had enough fuel to do any more than that, say 1.1 launches, then the OP is correct.
But, again, WHO CARES about lunar orbit? I was indeed assuming that we wanted to go to interesting places in the Solar System. If we want to go somewhere boring, it's a lot cheaper to go to my home town.
Now, I don't know the actual answer, but I bet its a lot closer than if you simply treat the moon as one-time detour for a spacecraft on its way somewhere else. If you aren't returning to the moon, it obviously doesn't make sense to stop there as you point out.
Again: I contend that the moon is not a useful place to go. There are indeed good scientific reasons to go to the moon, but no industrial, economic, or exploratory ones. I'm certainly not discounting the value of the science, but I don't think it's the most important objective. (It's also one of the less expensive objectives, which is cool indeed.)
Until we build a base there, we can't put a spacefaring industry there. That's why its so important to look for ways to use the moon's resources, and put it to the test with a "useless" (for now anyway) moon base.
What resources are those? Yes, fine, HE3. Get back to me when we've got a reliable fusion reactor.
There's also the issue of figuring out how to live in space for long periods.
That problem is well understood.
A 2-year mars mission would be suicide unless we'd built up and tested our systems on an easier problem (a moon base would be perfect for this).
I think that's a silly contention. Risky? Yes. Most valuable enterprises are. Suicidal? Come on.
After all, there's a reason we had the Mercury and Gemini programs before Apollo. We didn't just build the moon mission from scratch.
But, having built the moon mission, building another moon mission is not useful. We've learned those lessons. Time to take the next step.
What color is the sky on your planet?
That's what they SAY, which is different from what they DO.
I was making a joke. You can get your nose out of joint all you want. Whatever makes you happy.
You can see my math when I see your money, amigo.
Just a hint: The delta vee to take off from earth, land on the moon, take off from the moon, and go elsewhere in the solar system is rather higher than the delta vee to just take off from earth and go elsewhere in the solar system.
Until there's spacefaring industry on the moon itself (working with indigenous resources), the moon is not a useful space base.
There's an argument to be made for on-orbit assembly, but I think not a terribly strong one. Systems integration is hard, and doing things in orbit is really hard.
"The Case for Mars" by Robert Zubrin talks about this in some detail. Good book.
"Still, I'll bet that one Earth-to-moon flight carrying fuel would power more than one launch from the moon, though."
I'll take that bet. How much you want to put up? Shall we use your orbital mechanics text, or mine?
How many objects you've ever seen are manufactured by autonomous robots?
How many complicated engineering projects have been built by tele-operated systems at the end of a long time lag?
Without flash, there is no Homestar Runner. Without Homestar, there is no joy in Mudville.
I have an ad blocking plugin that works just fine, and I still get Homestar. Best of all possible worlds.
By "combine harvester", I believe you mean "cotton gin". But OK.
Yeah, I've totally lost the thread of your argument.
My Treo 650 is a fine phone, a great PDA, and a very acceptable portable web/email device. It's not perfect, but it works fine.
So, again: Well designed devices are good. Poorly designed devices are bad. Whether a device is "converged" or not does not locate it on the wellpoorly designed axis.
I don't know...I like being able to get up-to-the-minute bus schedules on a device I carry in my pocket.
I don't care if my phone has a web browser, or a game of Snake, or a camera...as long as those don't detract from its utility. In my experience, they do not.
You mentioned a swiss army knife, and conveniently ignored my Leatherman comment. Swiss Army knives are pretty lousy at a lot of tasks. My Leatherman is surprisingly good at a fair number of tasks.
Badly designed "converged" devices are bad. There's no argument there.
Why is it that just about every missive I've ever read about how people never use multi-function devices was generated on the most powerful multi-function device in history?
I like my Leatherman. I like my Treo 650. I like my various personal computers. Well designed "converged" devices mean that I can schlep less stuff, and that's good.
In my stereo cabinet, the convergence argument is definitely a more open issue. However, I haven't had a dedicated CD player in my stack for ten years.
Deceleration? Whaaaa? You were reading bad 60's comic books, weren't you?
If you're travelling fast enough to light a scramjet, slowing down is EASY.
Thing about "pointing in the right direction"...when you're targeting things that move, the "right direction" changes while your weapon is in flight. Hence, "guided missile".
A ballistic weapon is great against point defenses, and short-range targets. Not so much for naval battles.
If I had the experience and equipment to sail myself, sure. Packed into an ocean liner, not so much.
"America as a rouge superpower."
Yeah, just wait until we put on our lipstick and eyeshadow! THEN you'll see what a properly made-up superpower looks like!
Huh huh...and the Russians used pencils in their spaceships. Stupid Americans. Huh huh.
(riiiight.)
*eyebrow*
Um, you understand that there's a non-trivial amount of R&D that will need to happen between the fired-straight-at-the-ground test article, and a missile that can actually maneuver at the end of its flight and not disintegrate, don't you?
I sure hope so, because it sounds an awful lot like you're talking out your ass.
"Is our collective time really that valuable that we can't relax and enjoy a journey?"
I've got no idea who speaks for the value of "our collective time", sometimes getting somewhere quickly is nice. Do you seriously spend time thinking about things like that?
If I want to visit Australia, and I have two weeks' vacation, I'd like to get there in a reasonably short amount of time. Two weeks on the open ocean doesn't sound like a heck of a lot of fun.
Having said that, changing an eighteen hour flight (incl. time in the terminal) into a ten hour flight (incl. time in the terminal) doesn't necessarily simplify my logistics.
Having said that, the reason we have free markets is so that people whose value assignments differ from mine can spend money to get things that aren't necessarily valuable to me. Shocking, wot?
What are you talking about?
The requirements for moving humans are very different from moving bulk cargo, so I'm not sure that the efficiency calculation is quite as simple as you're making out.
People are pretty light weight for the amount of volume they require to be comfortable. Bringing 175 lbs of crude oil NY to Paris in 12 hours isn't very useful. Bringing a couple bazillion barrels in a couple of weeks is pretty darn useful.
(especially when you load the supertanker up onto big logs and roll it from the coast to Paris. That's the really efficient part.)
I don't have the numbers close to hand, but 747s at cruise are pretty darn efficient.
Using a totally separate engine system, or a staged aircraft (a la White Knight/SpaceShip One or the Pegasus rocket system).
That's a remarkably dumb comment.
Do you think there's only one acceleration that will get you to Mach 7? What do you suppose that acceleration to be?
Um, so on relatively long international flights (you know, like ones that go across big oceans), the time spent in the terminal is not as great as the time you spend in the air?
Like, I dunno, NY to Paris, or LA to Tokyo? Flights that take 12-18 hours? Am I ringing any bells here?
Yes, we're spending longer than ever in terminals, but I've got more faith in engineers making fast jets than in bureaucrats making meaningful and efficient security processes.
You made that acronym up yourself, didn't you?
Content Restriction Annullment would be a good thing. Protection of good things is often interpreted to be good. Your sig is not much with the sense-making.
Like what?
Basic science and engineering research is cheap, and the dividends are colossal.
At Mach 7, ocean is indistinguishable from ground.