Brad DeLong's Semi-Daily Journal (2004)

...except it isn't going to work. Hubble was designed to be serviced by humans; the interior parts are not accessible or repairable by any forseeable robotic mission. The idea is to fasten a kind of space tick to the bottom of the telescope and use it to point it after the gyros have gone to hell, but the real reason for this gadget is to deorbit the telescope, since chances are they won't get it into orbit in time to actually "save" the telescope (2007-2008 is the estimate for final gyro failure). And it certainly won't be able to install the $250 million worth of new instrumentation that has already been built.

And why is it that other lefties tend to be so anti-space program? Very short-sighted indeed.

Ms. Paxton,

Because many lefties believe (in the face of overwhelming contrary evidence) that money saved from the space program will be used to help Americans "here at home."

As opposed to the Americans that own (or used to own) Halliburton...

...and right there we have the reason I think many leftists are shortsighted at best and stupid at worst. Any intelligent plan for the future considers both short and long term. In the short term human spaceflight promises little more than pork for well connected congressmen. In the long term, it offers the hope of energy sources free from greenhouse emissions (from Space Solar Power Systems or lunar helium 3 fusion), as well as creating a new frontier for human settlement, to name just two benefits. NASA is horribly inefficient , but it need not be. There are ways to improve NASA's bang for the funding buck (for example stop treating it as a jobs program and turn it into a genuine exploration program).

When I can meet this strawman leftie that is so popular here ?

Manned space travel is *not* for the benefit of astronomers or those who are just curious to know how well potatoes can grow in free-fall. It is ultimately to make possible the very existence of our 600 billion great-great-great-grandchildren, and all the poets, painters, and inventors among them.

The money we spend on it wouldn't actually go all that far to solve earthly problems anyway, and there are certainly plenty of terrestrial boondoggles to cut first...

The strawman of the future generations is also ridiculous. If we want to start planning for a mythical future in space, we use robotics. The cost of launches needs to go radically down (two orders of magnitude less than commercial sattelite launches would be a good start), as does the risk (which has remained at roughly a 1/50 chance of killing everyone inside). And the best way to do that is practice-practice-practice in ways which don't kill people.

Look at the experiments which the shuttle astronauts died for: They could have either been automated and returned only data, automated and returned an air-dropped payload, or involved studying humans in orbit and the problems which would only arrise if space-travel becomes commonplace.

So as a net result, 7 people died because, politically, NASA needed to do "science" to justify the billions spent on manned space flight, on experiments that could have been conducted for 1/10th the cost if they were fully automated and placed on a commercial rocket, as the actual scientific payloads only weighed about 1-2 tons.

Manned space flight is now pork, pure and simple. It just happens to be letal pork.

Regarding Susan's comment, I'd have a hard time believing that it's a particularly stiff technological challenge to build a teleoperated robot with the dexterity of a human in an EVA suit. I'll concede that getting such a robot to HST in time is potentially another matter -- thus the conundrum that far and away the most scientifically useful shuttle mission in sight is the one that is off the table.

It's also hard to see an essential role for human spaceflight in constructing orbital power stations or mining the lunar regolith, as Andrew mentions, either, especially since we could probably expect greatly improved robots by the time either is practical.

I'd also note that there is a distinction that is in danger of being lost here between being anti-space program and anti-human space flight as it is currently constituted. From my own left-leaning perspective, I'd happily see the whole current NASA budget and then some spent on robotic science and exploration missions. (Of course, I'd be inclined to extract the funding for it from the likes of the boondogglier parts of the ballistic missile defense program.)

What about security concerns?

I recall reading someplace several years ago (perhaps during or about the time of Taliban operation in Aphganistan (spell?) right after 911) that one of the ten (?) principles (if not No:1) of US military doctrine was something like "to be the first to get your rear in "there"" -- wherever "there" may be in question.

The European GALLILEO (spell?) project is going to be built on some 30 satellites. Americans already have a comparable satellite system up there. The whole world -- but particularly western industrialized countries -- are becoming more and more dependent on satellites.

A few months ago when I briefly concerned myself with the subject of satellites (briefly till I got bored again), I stumbled on internet on proceedings of a conference of satellite manufacturer CEOs. One of them was discussing, at considerable length, about the missile capabilities of some of those so called "rouqe" states to zap the western satellites out of space (just a tiny nuke triggered at an altitude of a few hundred(?) miles up there would generate enough whatever "rays" to kill the satellites, they said), thus paralyzing the western countries at God knows what scale. And that meant "any body" could zap the satellites, unless precautions were taken.

Now; this subject was discussed before on this blog and I think it was A Zarkov who basically wrote that the Shuttle really didn't have any military value and that precision guided missiles would be sufficient for security purposes.

Even then, basics are basics. The Shuttle is a capability. Suppose US killed the Shuttle program without a substitute/equivalent manned-flight capability and some other country developed / acquired that capability.

Can US afford to allow that? Would that be OK from the point of view of defense/security to allow that to happen?

If that would be OK, then I have nothing more to say. If not, then US cannot afford to drop manned space flight programs.

But that should not preclude use of "robots" in space either.

The decision to build and operate the Space Shuttle makes a lot more sense if you look at it from the perspective of jobs in congressional districts rather than any technical requirements of space exploration.

I don't understand why risk to astronauts would be an argument against manned space travel. The astronauts are well aware of the risks, but the competition for astronaut positions is extremely intense. They obviously believe that a 1/50 chance of dying is a fair price for a trip to space. We shouldn't deny them that opportunity out of concern for their safety. Concerns about the cost of the space program are certainly legitimate, but concerns about the risk of death really don't make much sense.

Enough with the good-of-mankind and long-term benefit arguments. We should continue with a manned spaceflight program because I want to go! And enough with the too-risky arguments -- there are plenty of us who more than willing to accept that risk, just like the pioneers of aviation. Once I either get sent into space or I get old enough that I can't possibly qualify for the astronaut program, then maybe it can be discontinued, but not before.

Steve, do you honestly think that NASA takes that money, sticks it in the cargo bay of the shuttle, and then has the astronauts pitch it overboard? That money goes to pay for American jobs - good jobs, not shit jobs like Wal-Mart or Wendy's.

And Tom, you're right - it's possible to build such a robot, and I think we're going to see that soon (to service satellites in geosynchronous orbit in particular), but not in time for Hubble.

There's a place for humans AND robots in space.

Even in an EVA suit, the human hand is far more dextrous than any robot. It may seem surprising, but if you think about it, dexterity has clear evolutionary advantages even in primitive animals, and as such has been the beneficiary of tens of millions of years of evolutionary pressure.

They need to start building the Hubble 2, a space telescope with better optics and instrumentation that is completely servicable by robots. I think I am correct that the original Hubble was built over 20 years ago before the original MacIntosh computer, maybe in the days of Apple IIe.

Human travel outside our solar system will involve frozen fertilized eggs and the robots to incubate and raise them once new solar systems are reached.

Redshift: I take it that's supposed to be a parody of my post? I never said that we should have space travel simply because astronauts want to go into space. I said that the risk of space travel is no argument against it because astronauts willingly take that risk. It's extremely condescending to say that we should stop sending astronauts into space because it is too dangerous for them when that is obviously not what the astronauts want.

"...That money goes to pay for American jobs - good jobs, not shit jobs like Wal-Mart or Wendy's..."

There are ways other than the Shuttle program to create good jobs. If it is not a matter of security to have manned space flight, I think it is time to re-evaluate it and perhaps channel resources elsewhere, for example, medical research. Or maybe a drive to make "workerless factory" a reality, bringing down manufacturing sector employment to a level akin to that in agricultural sector. Or maybe a drive to bring about "workerless Wal-Marts and Wendys" -- to which space robotics would probably contribute greatly.

Annual budgets of NASA and NHI are about equal these days, at about USD 15 bn, I think. Should those figures stay as is? Should they go up? Down? If up, what other budget item should give in? Any ideas?

Susan Paxton wrote:
> And why is it that other lefties tend to be so anti-space program?

I was curious if there is any real evidence to support the (implicit) assertion above. Certainly it's not true that all "other lefties" are opposed to space exploration. It did not take too much searching to find results of a Zogby poll taken for the Houston Chronicle in 2003.
http://www.chron.com/content/news/photos/03/07/20/nasa/crosstabs.pdf

For instance, asked whether tax dollars on space should be increased, percentages were as follows:

Response: increased keep decreased ended notsure
Dem 27.5 44.1 18.0 6.7 3.8
Rep 35.8 47.2 10.9 2.6 3.5
Ind 34.2 44.9 14.7 3.2 3.0

(Interestingly, all 7 libertarians asked said "increased".)

If you use Dem as a proxy for "leftie" then I guess there is something to the assertion above, but it's not a highly partisan issue (compare to abortion or gun control for instance).

I would guess that some "lefties" (but not most Democrats who are pretty moderate anyway) may conflate space with military spending, and some may be expressing a distrust or lack of interest in technology (though the scientists and technologists I know tend to be left-leaning on average compared to polls of average Americans). On the other hand, you'd think a lot of Democrats would connect space with the inspiration of JFK.

Personally, I don't see why it should be a politically charged issue. And in fact, it is only somewhat partisan.

I agree with you, Paul, that it shouldn't be a partisan issue, but lefty bloggers in particular (not me, though) seem to have an anti-space program bias.

I have an aerospace eng degree and many of you don't know of what you speak.
There is no wealth of high paying jobs in this field as one person seems to think. The space program died shortly after I graduated in 1982. None of my classmates that I know of work in this industry and only a few worked in the aircraft industry. The military/Reagan was only interested in SDI. So quit blaming the leftists as you call them for the current state of the space program. The work has slowly been bid out to the lowest bidder and the consequence was seen in the last shuttle disaster.
As one writer mentioned the danger to men is not the reason manned flight is a waste. The waste comes from the support systems to keep humans alive. Food, oxygen, and all the other thing need to keep people alive are not need by robots. Since it takes an incredible amount of energy to boost every pound into orbit this means more fuel or less cargo(instruments). This is why humans are a detriment to space exploration.

The high frontier argument is equally bogus. I spent 15 years working on and around many of these military systems(surveillance radars) and it doesn't take a nuclear warhead to knock out a satellite. The US did it with a missile launched from an F16 not an ICBM. Also those "rays" don't reach as far as mentioned, especially not the 22,000miles of a geosynch orbit. Also the miltary satellites are hardened for EMP/EMI as I assume are most commercial satellites which have to account for solar flare activity. The amount of space junk is also a bigger concern than these perceived threats.

I think redshift says it all as far as the reason for manned flight, it is something everyone dreams of doing for no particularly logical reason.

http://pep.typepad.com/public_enquiry_project/2004/06/where_are_the_i.html

Susan, why do you read Brad's comments as "anti-space program bias"? If we had NASA's budget but rational use of the money (robotic probes), we could have one hell of a space program. How does that get warped into "anti-space program"?

An unmanned space program is more practical than manned in the same way that in vitro fertilization is more practical than sex...

I'll readily concede that almost everything we do in space right now can probably be done more cheaply robotically. Most of the practical advances and economic contributions of space development -- GPS, satellite communications, future orbital solar power -- have come (or could have come) from the unmanned side.

But there are things robots can't do. Robots can't take "a giant leap for mankind". We don't need to send humans to the Moon, or Mars, or Titan because they're better than robots at taking rock samples. We need to do it because I've read too much science fiction and it pains me to think of humanity confined to this one little rock for the rest of time. To echo redshift, we need to go because *I* want to go someday, because my children will want to go, and their children...

P.S.: I agree that our current approach is maybe not the ideal way to accomplish this. At least historically, a lot of emphasis has been on military value. Right now, the mere two crewmen on the space station can barely keep up with the routine bolt-tightening. A one off trip to Mars would be a waste. I want to learn to live in space permanently. We should concentrate on mastering dirt cheap surface to orbit capability and move on from there.

P.P.S.: The danger argument is almost completely irrelevant. Offer me a trip into space with anything better than even odds and I'd take it in a heartbeat. I'll bet the Columbia and Challenger crews felt the same way.

Xavier - the reason the risk to astronauts is an argument against unnecessary manned space travel, is that protecting astronauts' lives in space drives up the cost like crazy. (RC started down this road, but it isn't just the food and oxygen, and their associated weight; it's also making sure the air stays in, the gamma rays stay out, and all that sort of stuff. The envelopes of flesh we walk around in, and their physical contents, are pretty damn fragile, so we pay through the nose to protect them.) I don't anticipate a movement by the astronauts to pay that premium.

Susan Paxton - re NASA as a jobs program, I think it's silly to talk about that without some evidence that its manned spaceflight programs give the best bang for the buck, so to speak, in that department.

Re the whole leftie business, I'm a leftie sure enough, but I'm a fiscal conservative, and have always been; used to be a Republican until Reagan came along and said GOPers aren't gonna be fiscal conservatives anymore.

Regardless of whether we're talking about NASA or Head Start, I don't mind paying taxes, but I want to know that the government's getting good value for my tax dollar. And quite frankly, I can't see what I'm getting from manned spaceflight that I couldn't get from unmanned at a fraction of the price.

I'd be curious to know how the cost of building a new Hubble compares with the cost of a space shuttle flight. Can we design a Hubble where the routine maintenance can easily be done by telerobotics, without a steep increase in the price? If so, we should. Then we could put it up in geosynchronous orbit, rather than in low earth orbit, do the routine repairs robotically, and replace it periodically instead of spending a billion bucks on a repair mission.

All I can see that we've gotten out of the manned space flight program since 1973 is that the shuttle helps us build the space station, and the space station gives the shuttle somewhere to go and something to do.

Right now, the whole idea of keeping the manned space program running, so that someday we will be able to live on other worlds, is crap. When the time comes that we've got somewhere else to go and a reason to go there, we'll be able to use the technology of that era to put a program together fairly quickly, just like we did with the moon program in the 1960s. In the meantime, the shuttle is just money thrown out the cargo bay.

RC:

"...This is why humans are a detriment to space exploration.."

I am no aerospace engineer butI had the impression that "exploration" as in space exploration was sort of a code word for manned space flight? And at least some authorities in space programs in various countries appear to think that it is for some reason essential to keep some amount of activity in the field of manned space flight.

At any rate, on the basis of what you are saying about the kind of "drag" the presence of humans in space flight brings onto a space mission; I am beginning to think that it would be entirely feasible, costwise, to plunge into trial and error space robotics programs, sending up robots again and again until they get it right.

My intuition tells me that the so called "reusable" vehicles would also be much easier and much less costly to develop and commission if they were not to have humans aboard.

My hunch also tells me that space robotics would very easily find its commercial applications here on earth, once developed and tested for space program purposes. This, combined with infinitely less risk to human life compared to manned space flight, would make justification of space robotics programs much easier.

RT wrote:
> When the time comes that we've got somewhere else to go and a reason to go there, we'll be able to use the technology of that era to put a program together fairly quickly, just like we did with the moon program in the 1960s.

In fact, when the time comes, we'll have much better technology. Suppose we had to repeat Apollo with all other things equal except for current computer-aided design software and the computers to run it on (assume for this thought experiment that we can only use the machines to run CAD software). That would already be a huge advantage over the first time around, and there are many other relevant technologies that have made substantial progress.

Establishing a permanent (or more precisely self-sustaining) human presence off the earth is going to require a lot more than rockets. You need to be able to exploit local resources. Considering the cost of keeping people alive, most of this will have to be done by machines whether or not there are people tending them. The current progression of technology is not a matter of losing the opportunity to colonize space. It's matter of building the necessary platform.

We don't really have a solid basis for an off-world base until we have completely autonomous machine manufacturing functioning on earth (this includes mining, refining, transportation, part fabrication, part assembly). Fortunately, this sort of technology is in principle market driven. One-shot space missions will never be.

In short, my view (call me Panglossian) is that the space age never ended; we just took the emphasis off sending people into space. But Intel is moving the space age along when they cram more transistors on a chip. So is Honda when they release the next Asimo robot. We need to learn how to do a lot of other things before there is much point in putting people up there.

One argument I'll consider is from those who want to walk on another planet in their own lifetime. The current technological path will probably not get them there. On the other hand, a path that will get them there won't necessarily get us to a self-sustaining off-world presence. And a very expensive way of putting a human on Mars sure isn't going to put ME on Mars or just about anyone else posting on this comment board.

"I'll readily concede that almost everything we do in space right now can probably be done more cheaply robotically"

Except of course, learning how to live and work in space. Which you would need to do in order to go live and work somewhere other then earth. Which you would need to do if you wanted to insure the human race had a future. But that might be the problem. It's costly, difficult, dangerous work. I think the calculation being made here is that the human race isn't worth it.

A robotic servicing mission to hubble that can do everything, or even most things a human astronaut can do, may need more then just better robots. It may need a launcher capable of throwing its weight. The talk I'm hearing here at work (the Space Telescope Science Institute) is that some of the proposed robotic servicing modules in design right now are treading close to the weight limit of the heavy lifting vehicles in our national inventory. Of course there is something that will throw more weight into orbit then that. But it's the shuttle.

We'd prefer a manned mission to Hubble because we have experience doing that, and we know it's possible to do all the servicing to the spacecraft that needs doing successfully. The astronauts know the risks and to an individual have let us know that they are willing to take them, so Hubble can keep producing the kind of science it does for years more. You should note that there is nothing on the drawing boards, even now, that will match Hubble's capabilities, let alone extend them with new technology. Not NGST, not the proposed European observatory. But we'll gladly embrace a robotic mission if that's the only chance we'll get to see Hubble to its original end of mission, in 2010, and maybe a few years beyond.

My personal fear is that O'Keefe will send a robot up to place a de-orbiting engine on Hubble, and nothing else, and call that a successful Hubble servicing mission. An administration that is putting creationist literature in the Grand Canyon visitors center, isn't one that's all that interested in science.

"Suppose we had to repeat Apollo with all other things equal except for current computer-aided design software and the computers to run it on..."

My understanding from the people I work with, is that we could not build another Saturn V launch vehicle, even if we wanted to. It's not a matter of the tooling being gone. There was knowledge of how to go about building the thing that was lost, when the people originally involved in the project moved on to other things, retired, and then passed away. We'd have to start over, not exactly from scratch, but near enough that we'd have to do the test programs all over again until we got something that could be flight certified. You'd have to ask, 'why bother'? Might as well design a whole new vehicle using current technology.

Winged shuttles were supposed to supplant ballistic vehicles. But the current shuttle was never supposed to last this long. If NASA hadn't wasted time and money designing paper shuttle replacements that never flew, we might not be having this discussion right now.

Somewhat apropos of this, Burt Rutan's SpaceShipOne just had the date for its first over-100km suborbital burn set.

Don't let NASA's headaches get you down. There's a future in space, it just won't be pursued by the US government.

"...We don't really have a solid basis for an off-world base until we have completely autonomous machine manufacturing functioning on earth (this includes mining, refining, transportation, part fabrication, part assembly). Fortunately, this sort of technology is in principle market driven. ..."

That means the communists will colonize space. :-)

Because "completely autonomous machine manufacturing" in all sectors will inevitably bring about the end of capitalizm and its replacement is going to be some sort of a democratic communism, with each individual being some sort of a financially independent aristocrat with his/ her own slaves, i.e., the machines/robots.

".... You should note that there is nothing on the drawing boards, even now, that will match Hubble's capabilities, let alone extend them with new technology. Not NGST, not the proposed European observatory...."

But, there is this:

http://ngst.gsfc.nasa.gov/FAQ/FAQans.htm#anchor3

"....JWST will have a much larger primary mirror than Hubble (2.5 times larger in diameter, or about 6 times larger in area), giving it much more light gathering power. It also will have better infrared instruments than Hubble, allowing it to see the formation of stars and galaxies (see below). Finally, JWST will operate much farther from Earth, where operations are simpler, and where giving the telescope a stable pointing is easier than with the Earth-orbiting Hubble...."

Is there something I am missing here?

"Regarding Susan's comment, I'd have a hard time believing that it's a particularly stiff technological challenge to build a teleoperated robot with the dexterity of a human in an EVA suit."

Why? Humans, even in bulky suits, have much more dexterity operating directly than they do teleoperating a robot, and, even if you had a perfect replica of a human you could at that distance, they'd be less dextrous, just from the (slight though it is at NEO distances) communication lag.

Because "completely autonomous machine manufacturing" in all sectors will inevitably bring about the end of capitalizm

Er, no. In fact, with everyone being a capitalist and no labor left, it would make a sort of perfect capitalism, without all the discontents of labor that Marx got all worked up about.

OTOH, as long as there is a market for human ideas and human creativity, there will still be some labor.

I maintain that if a fraction of the funds spent on manned missions over the past 4 decades had been invested in robotics and AI we would know exponentially more about the solar system and cosmos than we do now. And the spinoffs and terrestrial benefits would be greater as well.

We are squishy-soft pink things that are exceedingly easy to kill. A good deal of the cost of manned missions is to keep us alive throughout the flight and return us to earth relatively unsquished. We must travel in such a hermetically sealed environment that the average astronaut is no closer to being "in space" than you are sitting in your backyard. The only part of a human being that truly belongs in space is The Mind. And as one scientist recently noted about the President's Mars musings: We don't need to go to Mars. We're already there...

"...with everyone being a capitalist and no labor left..."

I am not going to be picky about labeling, of course; I am perfectly willing to call it capitalism. :-)

("Capitalism without labor" sounds a bit, uhm, theoretically awkward, but I'll let **full** economists be the judge of that.)

"...squishy-soft pink things ..."

Hey, hey, no porn, please!

RT - There already *is* someplace to go, and the time could be now. Today's technology is pretty good. All of the theory and key innovations are there - high strength carbon nanotube fibers, air-breathing rockets, high tech radiation shielding, nutrition and exercise, closed agriculture, fusion propulsion, von Neumann machines - all theoretically possible, some working models even. What remains are largely engineering puzzles. Thoroughly tractable ones when the money (not a lot even) flows to the right place. I don't see any *technical* reason why we couldn't have sustainable off-world colonies in the same time it took to go from the V2 to Apollo.

We actually only need a selection of these breakthroughs. Cheap launch via space elevator is not so important if you can leverage off world materials and manufacturing (so long as one way or another a pound of aluminum in orbit costs less than $10000). you don't need so much radiation shielding if you've got plenty of delta vee, vice versa, and etc.

However, the effectiveness of robotic scientific missions means that pure science is a poor justification for manned spaceflight. This is NASA's dilemma. They just need to stop being apologetic about it, manned spaceflight is its own justification.

That politics is a big reason why we're still stuck with the shuttle, even though it should have (and could have) been replaced with something cheaper and more reliable years ago. The ISS is still an important step in learning how to live and work in space. The problem is that it's premature, it would work a lot better if it were served by better launch technology. I am all for grounding the manned program for a short time, *provided* that that money (and more!) is invested in programs that will return it better than before.

"We don't need to go to Mars. We're already there." - Yeah, and if they'd had robots back in the 19th century I'm sure nobody ever would have ever settled say, Hong Kong. They could have just taken pictures...

I maintain that if a fraction of the funds spent on manned missions over the past 4 decades had been invested in robotics and AI [...]

I feel obliged to point out that a fraction of the amount spend on manned missions over the past 4 decades has been invested in robotics and AI.

In fact, I wouldn't be surprised if you added up total spending on manned space flight from all US sources, public and private, and total spending on artificial intelligence and robotics, public and private, over the past 4 decades, and found that the latter would exceed the former, so "multiple" might be more natural than "fraction".

I suspect you mean "If a substantially larger fraction..." (or "multiple...").

The thing I notice about those supporting manned flight is that their best justification is "because it is there".
If we can do space exploration more effectively without humans than why send them? What is their value added to the program?
The circular agrument that we need to send men in space so that we can figure out how men can live in space still begs the question why? Because we have screwed up earth and can no longer live here? The aliens are coming and will kick us out? No matter how you slice it there is little if any value added.
I called a space expert on this subject after reading his article. In an email here is what he said:

Thanks for your note. The justification for human space flight is like religion. Either you have it or you don't. I won't try to justify it
but I do believe in its worth. But if I had to choose (which I don't), I'd take robotic missions over human ones any day.

H Hickman

> Yeah, and if they'd had robots back in the 19th century I'm sure nobody ever would have ever settled say, Hong Kong. They could have just taken pictures...

I imagine Hong Kong was "settled" a good bit earlier. Wait! No need to imagine:

"Hong Kong has supported human life since at least the Stone Age."
http://www.lonelyplanet.com/destinations/north_east_asia/hong_kong/history.htm

On the other hand, we can now get back and forth from Antarctica relatively easily but there is little economic incentive to put a big city there.

Colonizing space as an end in itself is only an imperative for a small minority of enthusiasts. I suspect your assessment of existing technology is overoptimistic, but even if not, there incentive just is not there for most people. International treaties aside, it would be easier to live at the South Pole than in space.

Continued expansion of human population will require more resources than we have on earth. But I do not expect interest in commercializing space to grow until we cannot find enough terrestrial resources. And I don't expect space travel to become economically feasible until it is commercialized.

Meanwhile, I do not see any serious lost opportunity in focusing on terrestrial technology for now. I have heard the argument that we could squander all the terrestrial energy sources that would be needed to bootstrap into space. I don't believe that. Actually, I think that there is plenty of alternative energy but petroleum is unfortunately too cheap for the time being to make it worthwhile. Any elemental resource can be recycled using enough energy. I do not expect us to literally run out of resources for some time. Now we might turn the earth into a very ugly place, but people and technological society will continue.

People who want to be space pioneers clear won't be happy with my scenario, but apart from (possibly) deferring space colonization by a generation or so (assuming you could reasonably begin now), I just don't see the drawback in a larger sense.

"Is there something I am missing here?"

Yeah. NGST won't do as much of the spectrum as Hubble does. What part of it that it will do, it will do better then Hubble. But that's not all that Hubble can work with. Some science is going to be lost. And that's assuming that everything they have planned now for NGST will actually happen. It's been scoped back some already. There is a slight, but non-trivial worry that it'll be scoped back more. Then it starts becoming a question as to whether or not it goes up at all. Although I understand that they're getting ready to start cutting the mirrors for it, so maybe that won't happen.

That spectrum limitation is as I understand it, the problem with the new adaptive mirror technology they're using now, to get better imaging from earth based telescopes. It's a big improvement, but only in certain parts of the spectrum.

When Hubble goes, the ability to do some science is going to be lost. Maybe actually loosing it will spur people to do something to get it back again. But it will take years.

"People who want to be space pioneers clear won't be happy with my scenario, but apart from (possibly) deferring space colonization by a generation or so (assuming you could reasonably begin now), I just don't see the drawback in a larger sense."

It's gambling that a delay won't matter in terms of human survivability down the road. Take a look at Hubble's shots of what comet Shoemaker-Levy 9 did to Jupiter. Not all that impressive, until you consider that some of those black splotches are bigger then the planet whose air you are now breathing. And that's not all that space can do to us. In fact, we're still discovering new ways that the space our good earth moves through can hit earth's reset button.

Maybe it won't happen for a thousand years. Maybe it won't happen for a hundred thousand years, or tens of millions of years. Maybe it happens before we can have enough of a presence throughout the solar system that it won't matter. But maybe it happens in a timeframe when what we do now could have made a difference.

So the odds are against it making any difference at all. But it's still gambling with the future of the human race. And those stakes are high, regardless of the odds. Corporate polluters of the earth's environment are not being any more careless about the future of the human race.

We should take the survival opportunities we have. It's not a matter of Buck Rodgers wish fulfillment. It's a matter of securing our future existence as a species. This is why I'm completely floored by Brad's opinion on this. I'm at a loss to understand how he could imagine that there is "no reason--no reason at all" to have a human presence in space. We can imagine the need to lay the groundwork now for a sound economy in the future...but not the need to lay the groundwork now, for a secure future for the species?

The thing I notice about the arguments of the people against manned spaceflight is- wait, are there any of you, really? Nobody seems to be against the idea, not in the abstract. Mostly, you all seem to be against it *now*.

I don't think anyone at all has questioned the value of science missions, some just think it could be done cheaper with robotic probes. If you can see the value in studying weather on Jupiter, or finally deciding whether the universe is shaped like an ear horn or a pringles can, then why can't you see the value in learning how to make human beings thrive and multiply their way out into that universe?

There is also the vague notion that if only we didn't "waste" that couple billion a year on shuttle launches, we'd finally be able to solve all our earthly problems. Then, maybe a couple generations after world peace breaks out, those of us who feel like it will be allowed to buy one of the new bicycle driven rocket ships and pedal merrily off to Venus. Pfft.

A somewhat related argument is that if putting people in space permanently is possible (or worth anything) that private industry will get around to it eventually. I don't really buy this; I don't see the "killer app" that can bootstrap the process. Sure, private industry is already in space (thanks in no small part to government investment of an earlier age), but they're only into satellite tv, and losing money on satellite phones. There's a feeble chance that (unmanned) power satellites could be profitable. There's "tourism", but one millionaire a year does not really equal tourism. It would take a couple of orders of magnitude decrease in cost before real tourism could be remotely practical, so it's the chicken and the egg. To have industry in space you first need a market in space. The value here is not in trade with Earth, it is in expanding humanity's world (and humanity).

We do have the technology. It's not fantastically optimistic to think that we could build a space elevator(!), inside of a decade. That's assuming we can make a few more advances in carbon nanofiber composites, but I am sure those would be useful elsewhere anyway. And there's no reason we have to stop making supply runs to the ISS in the meantime.

So I ask you, given that with every second we drag our feet Comet Garret draws a few miles closer, why delay any longer?

(RE: Hong Kong, this may have been a bad example. I was looking for an obviously successful colonization that wouldn't bring up the spectre of exploition and extermination of native peoples. If it makes you feel better, just replace Hong Kong with the original colonization of the wilds of Asia and Europe by our distant African ancestors.)

Jack L,

Once again you refuse to make the point of significant advantage of this proposition, human as opposed to robotic space exploration. There is no point in the solar system which has a useable oxygen supply for humans, let alone a liveable temperature, gravity(bone loss), or radiation protection. So why exactly do we want to venture forth for human exploration?

You will be able to support only a few individuals. And they will do what? Look for martians? Exceed the capabilities of robotic probes? Answer the question and stop continuing on this pointless argument unless you have something which will enlighten us to the miraculous advantages presented in humans touching rocks on Mars or any other planet.

"So I ask you, given that with every second we drag our feet Comet Garret draws a few miles closer, why delay any longer?"

That's two t's. If you're going to name a mock comet of doom after me, at least get my name right.

I take it then, that your argument is merely to scoff at the idea that such a thing could happen. That's certainly one way to make a point. I remember when the images of comet Shoemaker-Levy 9 were first released, reading that a good many astronomers were amazed that the effect it had on Jupiter's atmosphere. Bear in mind that those earth sized blotches on Jupiter were caused by fragments of the comet, which had been pulled apart by the force of Jupiter's gravity. At the time it seemed that suddenly a whole lot of people started taking planetary impacts a lot more seriously then they previously had. Good thing the wake up call happened somewhere else.

And as I said, it isn't only impacts that can bring about a bad day on earth. A gamma ray burst hitting us with enough strength, can strip the atmosphere of its ozone. A large star going supernova, it doesn't have to be nearby if it's poles happen to be facing us, can do the trick.

Earth has had several mass extinctions in it's history. You think we're living now under some kind of grant of cosmic protection, do you? Or is your argument simply that, in the long run, we'll all be dead anyway? Learning to live and work off earth is hard, dangerous, costly work, and what is infinitely worse...we won't live to reap the full rewards of it. Some future generation will enjoy the benefits of all our labor, and don't you just know that they won't be sufficiently grateful to us anyway. They'll take it all for granted. You just know they will. Reason enough to leave them stranded here on earth...along with us. Isn't it.

Jack L.

Sorry if I misread your comments as being sarcastic. I went and reread and now I'm pretty sure they weren't meant to be.

RC- It's about manifest destiny, lebensraum, whatever you want to call it. Except without the genocidal ugliness, since there are no Martians or Moon people.

If demographic trends continue, the Earth's population will stabilize at about 10 billion in 50 years. Good thing too, since it probably couldn't support much more than that anyway. That's just not enough. Not enough poets. Not enough mathematicians. Not enough gardeners. Not enough authors. Not enough inventors.

It's also about insurance. About not keeping all our eggs in one basket, waiting for that killer comet or nearby supernova.

If our ancestors had all thought like you apparently do, the human race today would still be a mere handful of paleolithic people picking lice off each other in Africa somewhere (assuming some random plague or drought hadn't long ago wiped us out, all 3000 of us). There would have been no Confucius, no Michaelangelo, no Mozart, no Kepler, no Einstein. No pizza, no prom dates, probably no pottery, no fire, no agriculture.

I'm not talking about a little tin can with 20 researchers, "touching rocks on Mars" and waiting for the supply ship from the motherworld. We have to walk before we can run of course, but I'm talking about self sufficient cities, worlds of billions and billions.

The solar system abounds with energy and all the elements necessary to support life. Maybe not as conveniently packaged as on Earth (the anthropomorphic principle only goes so far), but perfectly useable nonetheless. Obviously no one could survive out there without being surround by lots of high technology, but that they will have. With a little inventiveness it's all there for the taking.

Bruce G- No, it wasn't meant sarcastically at all. Sorry I misspelled your name, I could have sworn I double checked that. C'est la vie.

Jack L,

That's all I was asking for and you stepped up. I didn't say don't send men into space, nor did I say we should end the space program.

What I am saying is that we need to know much about the worlds we are heading to and how to get there before we send people. What we have failed to do is use our intellectual resources to their best advantage.

We sent men to the moon and gain little for the effort, from the trip that is. The knowledge we gain was in the effort and little from the trip itself. We then squandered this intellectual momentum and ended up with the space shuttle and down scaled space station. We still have a weak understanding of long term human survival in space and there haven't been any new motor or spacecraft designs in years.

We need to quit wasting effort trying to keep others out of space and building more missiles if we ever wish to have a successful program. Then we have to do the research to develop viable methods to travel between planets and beyond. So I say it will take a lot of inventiveness, not a little, to get those things you wish for. And right now we do not seem to have the will.

As for your supernova fear, game over if that happens, wherever you are.

Folks; mankind would have a much better chance of inhabiting planets other than Earth (that is, do so before Earth was destroyed, if ever) if America realized universal mandatory education of 15 (or,16) years in arts and sciences - meaning every body would have to become an arts and science graduate before going to work or other studies in engineering, finance, etc as well as law and medicine -- and that would be true even if space programs were to be frozen still in their tracks right now for about, oh, say, fifty years. That's what I think.

The arguments that in the short term "all-unmanned" is better a better strategy is powerful. (Not necessarily decisive, especially if you ask what funding would be politically sustainable with an "all-unmanned" approach, but powerful.) For the long run, however, I submit (as an illustration, not a prediction):

"The population sustainable at steady state by the known resources of the Main Belt is probably limited by the nitrogen abundance. The limiting population appears to be close to 14,000,000 billion (1.4 x 10^16) people." John S. Lewis, "Resources of the Asteroids," Journal of the British Interplanetary Society, Vol. 50, pp. 51-58, 1997.