Q: Which of the states are most closely associated with the space industry?
A: Texas (Houston, home of NASA) and Florida (site of the Kennedy Space Centre).
Actually, I think you'll find that California is bigger in the space industry than either TX or FL. The states you mention house the primary NASA centers for manned space and for launch, but the bulk of the space contractors are based in California, Colorado, and the DC area. And NASA itself has centers scattered sll over the country, many of them contributing to the space program.
Uh... maybe I'm missing something, but if the value/pound is greater than the cost/pound doesn't that make it a good economic proposition? Or did you mean to say that the cost exceeded the value?
From my experience working in the space industry the number one problem with "government space" is the "government" part. Today's NASA is not the NASA of yesteryear that took us to the moon. It has an entirely different culture, a top-heavy bureaucracy, and employees that tend to be of a lower caliber than you see in private industry. The best of the NASA centers is JPL, and that's mostly because they're not a traditional NASA center - they have a different culture, and they pay their employees at industry rates instead of GS levels. But even JPL gets hamstrung by NASA headquarters idiocy at times.
While I agree that the push into space is important both in and of itself, and because of the impetus it gives to technology development, I don't think NASA is the right agency to be doing it. In fact, I'm not sure that any agency is the right one. If the government is doing anything in space (and that's a big if in my opinion) it should be setting policies and goals, and then running competitive bids for implementations (aside: this is a lot like what the X-prize crowd are doing). Instead, it has no policies or goals, comes up with implementations that are bad political compromises, and then hires contractors to build them. Throw in a government acquisition process that encourages rampant under-bidding, and you have a recipe for disasterously over-budget programs that achieve little or nothing.
Raw materials are a significant cost when we're talking about the scale of the sort of installations we're talking about; we're talking about billions in launch cost here.
Perhaps I should have been more clear - the raw materials could be boosted into Earth orbit from the lunar surafec, thus radically reducing launch cost. Of course, that doesn't get into the launch costs involved in getting the appropriate facilities set up on the moon, but they should be similar between the two proposals.
Controlling a massive satellite installation shouldn't be as much of an issue, since we are, after all, talking about a rocket scientists. We're not talking about high dynamic stress here, the control issues probably are easy compensatible.
It's not the dynamic stress that's the issue, it's the flexible-body modes and the massive amount of nonlinearity built into that kind of system. Regardless of what you think, it's not an easy problem to solve (even for rocket scientists).
That may be the case, but from what I understand it's rather difficult to become a pilot in the military. For one thing, your uncorrected vision has to be 20/20 or better, which eliminates a whole bunch of people. By the way, as I understand it, "uncorrected" means just that: no corrective surgery, no glasses, no contacts.
I don't think that's correct. Last I saw (this was about 4 or 5 years ago), the Navy required 20/30 vision or better, correctable to 20/20 (glasses or contacts) to get into the flight program. Post graduation from training you could drop as low as 20/70 (for "service group 1", which means you can fly anything), so long as it still corrected to 20/20. They didn't accept surgery back then, but I've heard rumors that has changed. Don't recall exactly what the Air Force standards are/were, but I think they were fairly similar to the Navy's.
Some of the other responses to this question have touched on orbital debris and the availability of raw materials, but I'm not sure that these are the real concerns:
Debris is something of a concern, but we orbit expensive comm satellites all the time without getting too concerned about debris issues.
While raw materials may be readily available on the moon, there's little reason they couldn't be boosted into Earth orbit to provide satellites. In fact that might be a good way to build the realy sats.
IIRC the major concern with building space-based solar power satellites has been simply figuring out a way to control them. Flexible-body dynamics and control can get fairly hairy. We face that to a certain extent with the spacecraft we presently fly (at least those with large solar arrays, like the BSS-702). But when you are talking about the size of solar arrays required for this kind of proposal the control problems get orders of magnitude more difficult. The problem goes away if you have your arrays mounted to the lunar surafce. Another option that can mitigate the control problem somewhat is breaking the arrays up into many smaller, independent segments (i.e. lots of smaller spacecraft). I haven't done the math or economic analyses to know how small they would have to be, and how the expense of a fleet of small solar power sats would compare against a lunar-based system, but that may well be one of the justifications they are using.
"everything as a stream of bytes approach"... Can someone explain whats so great about this? Doesn't that encourage ad-hoc interfaces, a poor programming practice?
Perhaps you should go and browse through Eric Raymond's new "The Art of Unix Programming" book (you can even find it free online). He discusses the stream approach, and why it's a good idea (vs say the object approach). I'm sure others have covered the same ground, but that's the reference I've seen it in most recently.
What about the (I forget what they're called) points in space around the earth and moon where the gravitational fields are balanced? It seems like that would be less dangerous given the number of asteroids that hit the moon.
They're called Lagrange points, or libration points. It's unlikely that we'll be messing with them anytime soon for some kind of manned platform because the dynamics in the vicinity of those points is extremely messy and nonlinear. Trying to plot a rendezvous there is either very hard, or very expensive in propellant, or both. Libration points have been pushed as a great place to sight stuff for years, but the reality is that most of the rationale for putting things there is based on a very simplified analysis, rather than a real understanding of what happens at those points. Which is not to say that they aren't useful (see SOHO or Genesis for example). But the effort required is, at this point anyway, only really worthwhile for missions that have a very specific need to retain a particular position relative to the sun and earth.
BTW, those asteroids that strike the moon have to pass through space to get there. Which means you're probably just as likely to get hit at a libration point. More likely if you buy into Martin Lo's "Interplanetary Superhighway" theories.
We have been prepared to take the Distro off-line a couple of times as a form of political action. It is important to realize that the software freedom status of GNU-Darwin was tenuous before the change to the APSL, so we were ready to cut our losses, and remove GNU-Darwin from the internet, if necessary. Now things have improved very much.
Which pretty much sums up why these guys will never be any kind of serious competition for any real free OS. Who the hell would place any faith in this distribution? Doesn't exactly sound like the kind of dependable OS I'd want to put on my critical servers if it's going to come and go depending on the current political situation. And what kind of idiotic form of activism is it that goes out of its way to inconvenience its supporters, rather than the people its protesting against?
However, such an argument fails precisely because a gun couldn't have stopped two airplanes from flying into the WTC.
Unless of course someone on the plane(s) had a gun, and used it to shoot the hijackers. Which might explian why the airline pilots union has been campaigning to let its members carry guns in the cockpit.
Hmmm... perhaps you'd better tell the folks at Spacex, Microcosm, and Blue Origin about your expert insights in to the costs and benefits of entering the launch market. They may want to rethink their business plans.
Not saying we sholdn't work on it. In fact, I'd argue that since it is so hard, and yet we know an asteroid will hit eventually, we should be working on it a lot more than we are now (god knows we had to fight hard just to get the funding for the study I was on, and that was a small scale project).
For snowballs a nuclear-powered mass driver may well be better.
There are three problems with using any kind of propulsive (as opposed to explosive) system to deflect an object:
Physically attaching the propulsion device
Attaching the propulsion device in the right place so that it thrusts through (or near) the object center of mass
Keeping the propulsion device pointed in the right direction (since most of the things we would want to move are rotating to one degree or another).
deflecting the path of an asteriod on a collision course would be a hell of a lot more difficult than you seem to think. I've not done the maths, but I'm not entirely sure that we're even up to the challenge just yet
I worked briefly on a study looking at this exact question earlier this year. Deflecting an asteroid is an extremely difficult problem. For starters, you need to be able to actually get to the asteroid in time, which requires either super-efficient propulsion that we don't have yet, or a lead-time that we may not be fortunate enough to get. Once you're actually at the asteroid, you need to get your nuke (and that's all that'll work in this situation) into the right position (assuming you can figure out what that actually is), and hope that it's big enough to do the job. That's assuming that everything goes right - in real life you probably want to send several nukes "to be sure", and then you get into issues with the accuracy of short-term orbit determination and deciding if you should use your next nuke or not.
Several useful excerpts from "The Atheism Web" Intro to Atheism (since they say it better than I ever could):
"Atheism is characterized by an absence of belief in the existence of gods."
"Disbelief in a proposition means that one does not believe it to be true. Not believing that something is true is not equivalent to believing that it is false; one may simply have no idea whether it is true or not."
"The term 'agnosticism' was coined by Professor T.H. Huxley at a meeting of the Metaphysical Society in 1876. He defined an agnostic as someone who disclaimed both ("strong") atheism and theism, and who believed that the question of whether a higher power existed was unsolved and insoluble."
"...the answer to the question 'Isn't atheism a religious belief?' depends crucially upon what is meant by 'religious'. 'Religion' is generally characterized by belief in a superhuman controlling power -- especially in some sort of God -- and by faith and worship.
(It's worth pointing out in passing that some varieties of Buddhism are not 'religion' according to such a definition.)
Atheism is certainly not a belief in any sort of superhuman power, nor is it categorized by worship in any meaningful sense. Widening the definition of 'religious' to encompass atheism tends to result in many other aspects of human behavior suddenly becoming classed as 'religious' as well -- such as science, politics, and watching TV."
So, according to the atheists themselves (and they back it up elsewhere on the site with OED quotations), atheism is "absence of belief", while agnosticism is "belief that we'll never know one way or the other".
Furthermore, even if you assume that the word 'atheism' refers only to so-called "strong atheism" (i.e. the assertion that there is no god), and further assume that holding any kind of belief about a god (even a negative one) qualifies as a religion, that still does not lead to the conclusion that separation of church and state is equivalent to the state pushing 'atheism' as a 'religion'. Separation of church and state means that the government takes no official position one way or the other, which is equivalent to "weak atheism" (absence of belief), or what we might call "non-theism" (since the meaning of the word "atheism" is in so much dispute). In terms of freedom and rights: not mentioning god is not the same thing as saying that god does not exist.
Atheism is the absence of a belief in God. It is not a religion. Atheism has no doctrines, no morality, no rituals, no organization, and no sacred writings. I would be interested in hearing about what makes you consider atheism to be a religion.
Seriously though, you are way off base regarding the effects of "invalidating the GPL", as numerous other posts have pointed out. Not only that, but it's not clear that SCO's suits against IBM and SGI would in any way affect the validity of the GPL.
This "crisis" is nowhere near as dire as you make out. Even if SCO gets exactly what they want, they will get a dead shell of an OS. The Linux userbase will migrate to a kernel not encumbered by SCO pettiness.
MER is using Consultative Committee for Space Data Systems protocols (although I'm not sure which parts of the protocol suite they are actually using). As far as error correction schemes go, they were considering using a CCSDS standard Turbo code. I'm not sure if that actually went through - if not they are probably using a Reed-Solomon code.
Yeah, and the Wright Flyer could only stay off the ground for around 12 seconds on it's first flight. Stupid Wright brothers! What were they thinking? That their Wright Flyer might actually be the first (albeit small) step towards something much more capable?
What killed Challenger was a stupid design that used solid motors on a manned vehicle, followed by an idiotic management decision to launch during weather conditions known to be outside the tolerance of said motors. What killed Columbia was a known design flaw that everyone ignored, and that probably could have been mitigated if the astronauts had (a) a better understanding of the problem (e.g. through recon satellite imaging), and (b) the ability to perform an EVA outside the cargo bay to evaluate the problem up-close-n-personal. I won't even get into whether or not the hole could have been patched - at a minimum they would have known that they shouldn't reenter, and could look for alternative options ("scramble" a shuttle? launch a couple of Soyuz capsules? ferry everyone to the station using Progress modules? Who knows what might have been tried?). Trying to claim that orbital flight won't work because NASA has saddled itself with an idiotic design is a stupid argument. The Russians seem to be doing ok on the manned front, and that's even with their well-known reputation for being a little "casual" on the safety stuff. Their system appears to be robust enough to allow them to be casual without generating casualities in the process.
The problem with NASA is that they are a government program, which means they have to come up with the "one true solution" to everyone's problems, and make a launch vehicle that's all things to all people. The beauty of the X-prize is that we'll get to see a whole bunch of different approaches. Some will work. Some won't. But we'll learn something from both, and hopefully that will allow manned orbital craft to evolve in the same way that early aircraft evolved.
Damn! Better alert Boeing (the Delta series and others), and Lockheed Martin (the Atlas series and others), and Orbital Sciences (Pegasus and Taurus), and let them know how amazing it would be for a private enterprise to succesfully launch into space and do something productive. Last time I checked, none of them are government departments.
The key question is whether or not it's possible for privately funded groups to get things into space. Right now every successful launch vehicle program that I'm aware of has been funded by a government. Which has led many people to believe that it costs so much to build a launch vehicle that only a government could afford it. Personally, having observed government space orgs an action, I'm more prone to believe that because launch vehicles have been government funded they cost a lot to build. Hopefully the X-prize guys, and groups like Elon Musk's SpaceX can validate that belief for me.
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A: Texas (Houston, home of NASA) and Florida (site of the Kennedy Space Centre).
Actually, I think you'll find that California is bigger in the space industry than either TX or FL. The states you mention house the primary NASA centers for manned space and for launch, but the bulk of the space contractors are based in California, Colorado, and the DC area. And NASA itself has centers scattered sll over the country, many of them contributing to the space program.
Uh... maybe I'm missing something, but if the value/pound is greater than the cost/pound doesn't that make it a good economic proposition? Or did you mean to say that the cost exceeded the value?
While I agree that the push into space is important both in and of itself, and because of the impetus it gives to technology development, I don't think NASA is the right agency to be doing it. In fact, I'm not sure that any agency is the right one. If the government is doing anything in space (and that's a big if in my opinion) it should be setting policies and goals, and then running competitive bids for implementations (aside: this is a lot like what the X-prize crowd are doing). Instead, it has no policies or goals, comes up with implementations that are bad political compromises, and then hires contractors to build them. Throw in a government acquisition process that encourages rampant under-bidding, and you have a recipe for disasterously over-budget programs that achieve little or nothing.
Perhaps I should have been more clear - the raw materials could be boosted into Earth orbit from the lunar surafec, thus radically reducing launch cost. Of course, that doesn't get into the launch costs involved in getting the appropriate facilities set up on the moon, but they should be similar between the two proposals.
Controlling a massive satellite installation shouldn't be as much of an issue, since we are, after all, talking about a rocket scientists. We're not talking about high dynamic stress here, the control issues probably are easy compensatible.
It's not the dynamic stress that's the issue, it's the flexible-body modes and the massive amount of nonlinearity built into that kind of system. Regardless of what you think, it's not an easy problem to solve (even for rocket scientists).
I don't think that's correct. Last I saw (this was about 4 or 5 years ago), the Navy required 20/30 vision or better, correctable to 20/20 (glasses or contacts) to get into the flight program. Post graduation from training you could drop as low as 20/70 (for "service group 1", which means you can fly anything), so long as it still corrected to 20/20. They didn't accept surgery back then, but I've heard rumors that has changed. Don't recall exactly what the Air Force standards are/were, but I think they were fairly similar to the Navy's.
IIRC the major concern with building space-based solar power satellites has been simply figuring out a way to control them. Flexible-body dynamics and control can get fairly hairy. We face that to a certain extent with the spacecraft we presently fly (at least those with large solar arrays, like the BSS-702). But when you are talking about the size of solar arrays required for this kind of proposal the control problems get orders of magnitude more difficult. The problem goes away if you have your arrays mounted to the lunar surafce. Another option that can mitigate the control problem somewhat is breaking the arrays up into many smaller, independent segments (i.e. lots of smaller spacecraft). I haven't done the math or economic analyses to know how small they would have to be, and how the expense of a fleet of small solar power sats would compare against a lunar-based system, but that may well be one of the justifications they are using.
Perhaps you should go and browse through Eric Raymond's new "The Art of Unix Programming" book (you can even find it free online). He discusses the stream approach, and why it's a good idea (vs say the object approach). I'm sure others have covered the same ground, but that's the reference I've seen it in most recently.
They're called Lagrange points, or libration points. It's unlikely that we'll be messing with them anytime soon for some kind of manned platform because the dynamics in the vicinity of those points is extremely messy and nonlinear. Trying to plot a rendezvous there is either very hard, or very expensive in propellant, or both. Libration points have been pushed as a great place to sight stuff for years, but the reality is that most of the rationale for putting things there is based on a very simplified analysis, rather than a real understanding of what happens at those points. Which is not to say that they aren't useful (see SOHO or Genesis for example). But the effort required is, at this point anyway, only really worthwhile for missions that have a very specific need to retain a particular position relative to the sun and earth.
BTW, those asteroids that strike the moon have to pass through space to get there. Which means you're probably just as likely to get hit at a libration point. More likely if you buy into Martin Lo's "Interplanetary Superhighway" theories.
We have been prepared to take the Distro off-line a couple of times as a form of political action. It is important to realize that the software freedom status of GNU-Darwin was tenuous before the change to the APSL, so we were ready to cut our losses, and remove GNU-Darwin from the internet, if necessary. Now things have improved very much.
Which pretty much sums up why these guys will never be any kind of serious competition for any real free OS. Who the hell would place any faith in this distribution? Doesn't exactly sound like the kind of dependable OS I'd want to put on my critical servers if it's going to come and go depending on the current political situation. And what kind of idiotic form of activism is it that goes out of its way to inconvenience its supporters, rather than the people its protesting against?
Not unless you consider the Democratic members of the Texas legislature undeserving ;-)
Unless of course someone on the plane(s) had a gun, and used it to shoot the hijackers. Which might explian why the airline pilots union has been campaigning to let its members carry guns in the cockpit.
LOL... not only has she (re)invented perpetual motion, but what other source of solar energy, aside from the sun, does she think there is?
Hmmm... perhaps you'd better tell the folks at Spacex, Microcosm, and Blue Origin about your expert insights in to the costs and benefits of entering the launch market. They may want to rethink their business plans.
I stand corrected. It's been while since I've hung out in Ankh-Morpork, but now that you've reminded me I realize that you are quite right.
I think you mean "Oooook!"
For snowballs a nuclear-powered mass driver may well be better.
There are three problems with using any kind of propulsive (as opposed to explosive) system to deflect an object:
I worked briefly on a study looking at this exact question earlier this year. Deflecting an asteroid is an extremely difficult problem. For starters, you need to be able to actually get to the asteroid in time, which requires either super-efficient propulsion that we don't have yet, or a lead-time that we may not be fortunate enough to get. Once you're actually at the asteroid, you need to get your nuke (and that's all that'll work in this situation) into the right position (assuming you can figure out what that actually is), and hope that it's big enough to do the job. That's assuming that everything goes right - in real life you probably want to send several nukes "to be sure", and then you get into issues with the accuracy of short-term orbit determination and deciding if you should use your next nuke or not.
"Atheism is characterized by an absence of belief in the existence of gods."
"Disbelief in a proposition means that one does not believe it to be true. Not believing that something is true is not equivalent to believing that it is false; one may simply have no idea whether it is true or not."
"The term 'agnosticism' was coined by Professor T.H. Huxley at a meeting of the Metaphysical Society in 1876. He defined an agnostic as someone who disclaimed both ("strong") atheism and theism, and who believed that the question of whether a higher power existed was unsolved and insoluble."
"...the answer to the question 'Isn't atheism a religious belief?' depends crucially upon what is meant by 'religious'. 'Religion' is generally characterized by belief in a superhuman controlling power -- especially in some sort of God -- and by faith and worship. (It's worth pointing out in passing that some varieties of Buddhism are not 'religion' according to such a definition.) Atheism is certainly not a belief in any sort of superhuman power, nor is it categorized by worship in any meaningful sense. Widening the definition of 'religious' to encompass atheism tends to result in many other aspects of human behavior suddenly becoming classed as 'religious' as well -- such as science, politics, and watching TV."
So, according to the atheists themselves (and they back it up elsewhere on the site with OED quotations), atheism is "absence of belief", while agnosticism is "belief that we'll never know one way or the other".
Furthermore, even if you assume that the word 'atheism' refers only to so-called "strong atheism" (i.e. the assertion that there is no god), and further assume that holding any kind of belief about a god (even a negative one) qualifies as a religion, that still does not lead to the conclusion that separation of church and state is equivalent to the state pushing 'atheism' as a 'religion'. Separation of church and state means that the government takes no official position one way or the other, which is equivalent to "weak atheism" (absence of belief), or what we might call "non-theism" (since the meaning of the word "atheism" is in so much dispute). In terms of freedom and rights: not mentioning god is not the same thing as saying that god does not exist.
Atheism is the absence of a belief in God. It is not a religion. Atheism has no doctrines, no morality, no rituals, no organization, and no sacred writings. I would be interested in hearing about what makes you consider atheism to be a religion.
Yeah, I bet Red Hat, Tivo, and Sharp (the Zaurus) are kicking themselves right now...
Seriously though, you are way off base regarding the effects of "invalidating the GPL", as numerous other posts have pointed out. Not only that, but it's not clear that SCO's suits against IBM and SGI would in any way affect the validity of the GPL.
This "crisis" is nowhere near as dire as you make out. Even if SCO gets exactly what they want, they will get a dead shell of an OS. The Linux userbase will migrate to a kernel not encumbered by SCO pettiness.
Actually, I don't think UV propagates very well through window glass...
MER is using Consultative Committee for Space Data Systems protocols (although I'm not sure which parts of the protocol suite they are actually using). As far as error correction schemes go, they were considering using a CCSDS standard Turbo code. I'm not sure if that actually went through - if not they are probably using a Reed-Solomon code.
What killed Challenger was a stupid design that used solid motors on a manned vehicle, followed by an idiotic management decision to launch during weather conditions known to be outside the tolerance of said motors. What killed Columbia was a known design flaw that everyone ignored, and that probably could have been mitigated if the astronauts had (a) a better understanding of the problem (e.g. through recon satellite imaging), and (b) the ability to perform an EVA outside the cargo bay to evaluate the problem up-close-n-personal. I won't even get into whether or not the hole could have been patched - at a minimum they would have known that they shouldn't reenter, and could look for alternative options ("scramble" a shuttle? launch a couple of Soyuz capsules? ferry everyone to the station using Progress modules? Who knows what might have been tried?). Trying to claim that orbital flight won't work because NASA has saddled itself with an idiotic design is a stupid argument. The Russians seem to be doing ok on the manned front, and that's even with their well-known reputation for being a little "casual" on the safety stuff. Their system appears to be robust enough to allow them to be casual without generating casualities in the process.
The problem with NASA is that they are a government program, which means they have to come up with the "one true solution" to everyone's problems, and make a launch vehicle that's all things to all people. The beauty of the X-prize is that we'll get to see a whole bunch of different approaches. Some will work. Some won't. But we'll learn something from both, and hopefully that will allow manned orbital craft to evolve in the same way that early aircraft evolved.
The key question is whether or not it's possible for privately funded groups to get things into space. Right now every successful launch vehicle program that I'm aware of has been funded by a government. Which has led many people to believe that it costs so much to build a launch vehicle that only a government could afford it. Personally, having observed government space orgs an action, I'm more prone to believe that because launch vehicles have been government funded they cost a lot to build. Hopefully the X-prize guys, and groups like Elon Musk's SpaceX can validate that belief for me.