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Uncertain Principles

Physics, Politics, Pop Culture

Saturday, January 17, 2004

No Space Telescope Left Behind

While link-hunting for Yet Another Space Post (which is refusing to really come together in the way I'd like, so it'll be another day or so), I ran across a post where Rand Simberg calls me stupid. Well, OK, he actually calls Kevin Drum dumb, but I'm lumped in with other Bush-bashers. Simberg writes:

The sense one gets from much of the commentary is that they'd favor the proposal if it were coming from a President Gore, or President Dean, but if Bush is proposing it, there's obviously something evil and cynical about it.

[...] It would be nice if the policy could be discussed on its merits or lack thereof, but I suspect that that's a forlorn hope in a Red/Blue America.

That's at least half true-- I know that Gore's a geek, so if he announced a new space program, I'd figure he meant it. Dean, I don't know well enough to say.

But it's not really political partisanship that makes me leery of Bush's plan (though I do loathe the man and his administration). It's a sense of pattern recognition-- we've seen this before, after all. We've had funds promised for the rebuilding of New York City, that somehow failed to materialize. We had promises that the rebuilding of Afghanistan would be done right this time, followed by a budget submitted to Congress with no money for Afghanistan. We've watched them make promises to Pakistan, and then sell them out. We've seen more money promised for fighting AIDS in Africa, and then found that it was just a re-allocation of existing money. Again and again, we get proposals that sound great in ten-second sound bites, that turn out to be far less than they seem-- they end up as window dressing, or unfunded mandates, or just shady ways of killing off other programs.

And now, we get nice talk about space, followed by this:

The National Aeronautics and Space Administration decreed an early death yesterday to one of its flagship missions and most celebrated successes, the Hubble Space Telescope.

In a midday meeting at the Goddard Space Flight Center in Greenbelt, Md., two days after President Bush ordered NASA to redirect its resources toward human exploration of the Moon and Mars, the agency's administrator, Sean O'Keefe, told the managers of the space telescope that there would be no more shuttle visits to maintain it.

The stated reason is that safety upgrades to the Shuttle can't be completed in time to complete the next scheduled maintenance flight, and rescheduling it would cut into the construction schedule for the International Space Station. Never mind that, in terms of getting useful science done, they'd be better off crashing the ISS into the ocean, and doing nothing but Hubble maintenance missions for the next several years...

So, yeah, I doubt the sincerity of the Bush plan. And I think I've got statistics on my side.

Posted at 10:53 PM | link | follow-ups | 4 comments

Friday, January 16, 2004

Quality American Engineering

I drive a Ford Taurus, which leads to a bunch of sneering by people who drive fancier foreign cars, but you have to give them credit for at least a few technical innovations. Such as the foul-weather sensors embedded in the tires.

I've had two flat tires on this car: one occurred a few years ago, when it was pouring rain (and Kate and I were headed out of town for the weekend); the other was this morning, with wind chills dipping down to -30 or so. Really, the technology used to determine acceptable times for a failure is a remarkabkle bit of work.

I should also note that this is an area where we really need to work on gender roles and expectations. While I was crouched down in the snow, loosening lug nuts (helpfully, the tire iron is longer than the diameter of the rim, so it's not possible to turn it all the way around), a woman on her way to work stopped to ask me if I'd like her to call someone.

"No, thanks, I've got it," I replied. And only after she left did I realize that, really, that was the only sensible course of action. I should've called AAA, and waited in the warm car until someone arrived to deal with the tire.

But being an American male, I am socially programmed to care deeply about the opinions of tow-truck drivers. Were I female, or even just small and weak, I could've gotten away with calling for help, but as a healthy young man, I would open myself to scorn by asking for assistance with an automotive problem, and that thought was worse than -30 degree wind chill. So I changed it myself.

It's been about three hours since I got in to work, and I still don't feel warm.

Posted at 1:23 PM | link | follow-ups | 2 comments

Wednesday, January 14, 2004

"Are We Going to Use the Whole Book?"

With classes having started up again, I would be remiss in my pedagogy-blogging duties if I failed to notice two recent posts on the Textbook Problem, one from Pedablogue, the other from Pharyngula. This is one of those recurring issues that I never really realized were part of the teaching process.

It's a particularly troublesome issue in the sciences, because the books are so damnably expensive. The textbook we're using for the intro class that I'm teaching costs students somewhere in the neighborhood of $100 new (20% less used) from the campus bookstore, which is a lot of beer and pizza money for a college student. Granted, this will be used for at least two terms of physics (assuming they take that much), but a lot of the students resent the expense of the books, particularly when they find out that we only use the first half in the first course. There's a two-volume version of the book, which splits fairly nicely around where our course break falls, but the bookstore only sells them as sets, which causes even more grumbling.

On top of that, there's the fact that publishers are constantly putting out new editions of the big texts, so the book you have now won't necessarily be the one you'll be using next year (meaning all your lecture notes need to be revised to keep up, and you have to pick new homework problems...). And when the edition changes (usually for the worse, as P.Z. Myers notes), the cheaper used copies aren't available any more, and again, there is wailing and gnashing of teeth.

Throw in the fact that I don't actually like any of the textbooks I've used all that much, and... well, it's a bad situation all around.

Posted at 9:04 PM | link | follow-ups | 14 comments

Age and Guile Beat Youth and Superior Physical Conditioning

Pick-up hoops anecdotes have been lacking recently, because my teaching schedule didn't allow me to play basketball at lunchtime during the Fall term (I was teaching right after lunch, and wouldn't've had time to shower, change, and grab some food before lecture). I've got a better schedule this term, though, which means I've been able to start playing again-- I get there a little late, but I can get a decent run in.

Today, I arrived to find a larger-than-usual crowd, because a bunch of football players were at the gym for their off-season workouts, and had decided to play hoops. The last time this happened, they had enough guys to get their own game going, and wouldn't play with the regular lunchtime crowd, but today, they were a few guys short, so we put together an "Old Guys vs. Young Guys" game-- five guys from the football team against four faculty/staff types and one extra football guy. The teams probably averaged 32 and 20 years of age, respectively.

We trounced them. The final score was something like 15-10, and they made a late run to get it that close.

These games are actually fairly common in any mixed crowd-- there's always a contingent of younger guys who will try to get this sort of game going. The surprising thing (for the young guys, anyway) is that it's not uncommon to have a lopsided Old Guys victory, even when the younger players are much stronger and in better shape (as these guys were). Partly, it's a matter of pride-- even a fat slob like me can rally up a good game or two when presented with the chance to show up cocky young guys-- but there's also a selection effect. Guys who are still playing pick-up hoops with college kids at age 30+ have probably been playing for a long time, and will know at least a few tricks of the game (the four of us were probably four of the ten best players in the regular lunchtime crowd (which includes a few students and recent alumni) and three of the top five). People who aren't any good usually drift away from the game, and don't find themselves on the "Old Guys" side.

I think we definitely would've won a second game, but I'm not sure I would've had the legs for a third win. The best-of-seven result will have to remain an open question, though (another one for sports talk radio...). They turned down the traditional offer of a rematch, and quit the gym with the impression that I'm a much better player than I really am.

It's good to be a wily old guy... I'll pay for it tomorrow, but that was fun.

Posted at 8:41 PM | link | follow-ups | 3 comments

Monday, January 12, 2004

The Moon is a Harsh Wossname

(Third in a series of whopping huge posts about space. Posts one and two.)

It's a little foolish to attempt to comment on the merits of Bush's new space proposal, which is still mostly vapor at this point. I haven't seen a clear breakdown of exactly what would be involved, and probably won't until it's officially announced this week, with slick charts and PowerPoint slides. Of course, refraining from comment on the basis of insufficient information would run counter to the whole blogging ethos, so I'll feel free to spout off. I should also note that this is the least well-founded portion of my commentary, consisting primarily of my own opinions and speculation, and drawing less on the comments of very smart people who actually know what they're talking about. Caveat lector, and all that.

I should also say that I tend to agree with those who say that the whole mission-to-Mars thing is completely ludicrous on financial grounds. We just don't have spare billions to start throwing at the space program, and gutting the rest of NASA to pay for it would be exceedingly stupid. This isn't a high priority at the moment, and any argument about whether the proposal makes sense as a whole starts and ends right there.

That said, it's still sort of interesting, in an academic way, to think about whether the mission as proposed makes sense from a technical standpoint. That's what I'll be talking about in what follows.

The skeleton of a plan that I've seen cited has three main elements: 1) Retire the Shuttle fleet, and replace it with a more Apollo-like "Crew Exploration Vehicle," capable of reaching orbit, or traveling to the Moon and back. 2) Start sending manned missions to the Moon and back, beginning with stays of a few days, and working up to a more permanent presence there. 3) Once a Moon base is set up, send manned missions to Mars, on the same sort of basis. The first element is relatively uncontroversial. There are people who think we should replace the Shuttle fleet with something more ambitious (space planes or space elevators), but basically nobody who would argue in favor of keeping the current system.

Technical objections to the plan center around the second step, with most people arguing that sending manned missions to the Moon is idiotic, and probably counterproductive. They tend to prefer either a bigger space station at the stable Lagrange point between the Earth and the Moon, or something like Robert Zubrin's "Mars Direct" plan, which involves sending robot missions to place supplies on Mars which would then be picked up by astronauts, and used for the return trip. There's some merit to these-- Zubrin's plan, in particular, has some really good points-- but I think that the Moon is not as idiotic a destination as most people think.

The objections to using the Moon as a starting point for a Mars mission all center on gravity. It takes a tremendous amount of money to lift anything out of Earth's gravity well, the argument goes, so why would you want to squander that by going to the Moon, which also has a gravity well (albeit a shallower one) to be overcome before you launch anything to Mars?

Gravity is actually one of the reasons why I think the Moon might make more sense, though. As anybody who follows the International Space Station program knows, building things in zero gravity has turned out to be an excruciatingly slow process. In part, this is because, as Bob Park noted in Congressional testimony, free fall turns out to be a very stressful environment for people to live in. There's also a Newton's Laws problem-- on Earth, you can rely on gravity to keep yourself in place while you move heavy objects around. In free fall, the Third Law will get you every time. Just unscrewing a few bolts turns into a huge ordeal, requiring careful bracing against big objects, lest reaction forces start you spinning.

Working on the Moon might alleviate those problems. The gravitational force on the Moon is less than on Earth, but it's still there, which ought to reduce the stress on humans working there (I don't think we have anywhere near enough data to know). And the combination of gravity and a solid place to stand might make construction projects go more quickly. The combination of those two things could easily be enough of an advantage to make the Moon a worthwhile starting point.

(There are other arguments that are sort of a wash, too. The Moon is resource-poor, lacking even an atmosphere, so you'd need to ship everything up from Earth. But that's going to be true anywhere you go, and the Moon isn't entirely useless-- after all, when it comes to building human habitats in space, it's hard to beat the radiation shielding properties of a meter or two of solid rock...)

There's a bigger reason why the Moon makes sense, though: you need to crawl before you can walk. Mars Direct is a wonderfully clever plan, but it suffers from the same arrogance of complexity that I mentioned in my last post. Zubrin's plan calls for advance teams of robots to land on Mars with a vehicle that can be used to return to Earth, a year's supply of food, and a reactor to make fuel and water from resources found on Mars.

It's a nice idea, and builds off NASA's experience with unmanned missions, but it's a huge gamble for a manned mission involving months of travel to get there and back. For the Mars Direct plan to work, lots of things needs to go smoothly-- the unmanned craft need to land safely, the food and tools need to arrive without damage, the assembly robots need to do their jobs correctly, and you've got to end up with enough usable fuel and water for the trip back. If any of those processes fail (keep in mind, we don't have a great track record with landing things on Mars safely), or anything unexpected happens (say, a severe wind storm (Mars does have weather) that damages some crucial component), the world gets treated to the spectacle of astronauts starving to death on CNN.

Elements of the plan are very good, particularly the idea of unmanned advance missions to put supplies in place. But this is the sort of project that demands extensive testing before lives are bet on it, and that's where the Moon comes in. We already know that it's possible to send manned missions to the Moon with enough supplies for the round trip, which gives you a safety net. Send the robot supply missions to the Moon, let them do their thing (you'll need to send along a few air tanks to simulate the Martian atmosphere, which the Moon lacks, but since they don't need to have enough fuel to get to Mars, that should be fine), and then send manned missions to pick the stuff up. If there's a problem, they can carry enough food and fuel with them to make it back, and in the absolute worst case, they're only a few days from Earth. If it does work, hey, you've got extra supplies in place to use for a Moon base. After it's worked a few times on the Moon, then try it on Mars.

(An even bigger problem with Zubrin's plan is that is sounds like a "proof of principle" sort of mission, that doesn't really lead anywhere. You can send men to Mars and back, and do science more efficiently there, but getting from there to permanent colonies still seems like a big stretch. He does claim to have a plan for that, too, but I don't care enough about it to buy his book and find out what it is, so I'll defer to people who've read it...)

If the goal of a manned space program is to eventually put permanent colonies on other planets, going back to the Moon seems like an eminently reasonable first step. Yes, there's nothing there that anybody wants (at least until helium-3 fusion becomes practical), and yes, a self-sufficient Moon colony would be extremely difficult to build and maintain. But it's a convenient place to test out a lot of techniques and technologies that would need to be used in more ambitious manned missions, and its relative closeness to Earth could provide the kind of safety net you need to avoid catastrophe.

Of course, there may be stronger arguments against going to the Moon than what I've heard-- for that, you'd need to consult actual rocket scientists. And again, there's a solid case to be made that this makes absolutely no financial sense at the present time. But as a purely academic exercise in imagination, it strikes me as not actually as terrible a plan as other commentators have claimed.

Posted at 7:16 AM | link | follow-ups | 8 comments

Sunday, January 11, 2004

You Like Me... Those of You Who've Heard of Me Like Me...

I was pleasantly surprised to discover from a vanity search at Technorati that this blog was nominated for a Koufax Award (for left-leaning bloggers) over at Wampum, in the category "Most Deserving of Wider Recognition." I guess it's a good thing I finally put up some new content...

I'd exhort people to go over there and vote for me but, honestly, some of the other nominees deserve it more than I do (especially since I've been deliberately avoiding much political posting lately). I'd recommend some of them, but, well, I've never heard of many of the other nominees (unsurprisingly, given the category...). Given the quality of the ones I do recognize, though, I'm flattered.

I expect you could do worse than to check out every blog on the list. Which I'll probably be doing later, when I get sick of grading homework.

Posted at 7:39 PM | link | follow-ups | no comments

Insidious Wastes of Time, #137 in a series

Via Pharyngula, a new insidious waste of time: The World as a Blog. It's a site that plots the locations of recently updated weblogs, including ones in New Zealand, Iceland, and a point a bit off the coast of East Africa.

This is basically with a nifty graphical interface, and the signal-to-noise ratio is about the same. Still, it did turn up one good site, Bear Left at Unnamed Road, which would be even better if there were dates associated with the posts. And so, of course, like a slob in a casino whose first quarter hit a minor slot payoff, I'm going to sit here looking at it for a while...

I no longer wonder how I got any work done before the Internet.

Posted at 7:30 PM | link | follow-ups | 1 comment

The Arrogance of Complexity

There are essentially two arguments for why we ought to support manned space flight, and if you dip into the comments at any of the other fine blogs linked in my last post, you'll find plenty of people offering different variations of each. One is a sort of Manifest Destiny argument-- that we as humans have an inherent drive to explore and expand, and this must inevitably lead us into space. The other is the Paranoid Chicken argument-- that we can't have all our metaphorical eggs in one basket, and putting colonies on some other planet is imperative because it's only a matter of time before some event (natural or otherwise) brings civilization to an end.

These are fine arguments, as far as they go, but neither of these is an especially convincing argument for funding the program we have right now. There's not a lot of exploring of the solar system that people can do better than robots, at present, and putting a self-sustaining colony on another planet is decades off, at best. Given all the other things we have to deal with on Earth at the moment, there just isn't enough spare money to make much immediate progress on either front at the moment. Delaying the rush to space a few years (or even a decade or so) isn't going to have much long-term impact.

More importantly, the current space program doesn't actually do much of anything to advance either of these goals. When you talk about manned missions, what we have is not so much a space program as a low-Earth-orbit program. The Shuttle barely gets out of the atmosphere, let alone into interplanetary space. And it's really not generating any momentum to go beyond that level. Another twenty years of dinking around with the Shuttle and the International Space Station won't get us any closer to putting colonies on other worlds, or even having the ability to detect and divert those killer asteroids that space advocates are so worried about. We'd probably be better off with no manned space program at all than what we've got now.

A large part of the problem is the Shuttle itself. The basic concept is a good one-- a reusable launch vehicle capable of lifting a large payload into orbit and returning safely to Earth-- but somewhere in the long design process, most of those virtues got lost. The payload isn't all that large, the turnaround between missions has never been as fast as advertised, and it's not even re-using most of the bits that supply the lift.

There's also an element of hubris in the problems with the Shuttle-- it was assembled using things that we thought we understood, and clearly, they don't work as well as expected. It's an absurdly complicated system, one that requires a huge number of elements to function properly for safe operation, which is the sort of thing that should only be attempted when everything involved is well understood.

The Columbia disaster is a good illustration, as I said last year. The safe return of the Shuttle is entirely dependent upon the heat shields and tiles, which are known to be fragile (tiles have been falling off the damn thing from the very beginning), and potentially subject to damage on launch. And yet, not only was there no way to repair damage to the tiles on the wings after launch, there wasn't even any way to check whether there'd been any damage done.

That's just insane. If somebody offered you a car that had a non-zero probability of containing a bomb that would be armed on ignition, and explode violently when you stopped, killing everyone inside, you'd be a fool to take it, let alone pay $4 billion a year for it. And yet, that's what we've got with the Shuttle.

(A case could probably be made that the "we can't even check it out, let alone fix it" thing was a cultural failure as much as an inherent technical problem with the Shuttle. The fatalistic attitude NASA seemed to take toward the whole thing is a far cry from the "can-do" attitude of popular myth (It's not something you can imagine Ed Harris saying in Apollo 13, for example). There ought to have been some way to jury-rig things to allow a look at the underside of the Shuttle, and go from there. This is highly dependent on how much truth there is in those myths, though, which is something I'm too young and ill-informed to evaluate.)

I'm old enough to remember when the space program was still exciting, and enough of an SF fan to find the idea of off-planet colonies incredibly cool, but this isn't helping. If this is the sort of thing we're buying with the Shuttle program, it's time to scrap it and start over.

There are lots of Shuttle-alternative proposals out there, ranging from the fairly reasonable (go back to big rockets) to the almost-indistinguishable-from-what-we've-got (the "space plane" proposals), to the insanely ambitious (a space elevator). The "space plane" idea is basically the Shuttle as it was meant to be, but I don't really trust it to avoid the failings the Shuttle has. Space elevators are a lovely idea, but have two major defects: 1) materials technology just isn't there yet, and 2) anybody who thinks this is a Good Plan in a world containing maniacal terrorists really needs to go read the end of Red Mars again.

(A fourth option would be to basically put manned space flight on hold until technology advances to the point where we can do it more safely and cheaply. Some might claim that that's actually what we've got now-- a $4 billion/year holding pattern...)

In the end, I lean strongly toward the first option-- we don't have to go all the way back to the tiny capsules on huge rockets of the Apollo days (though "Spam in a can" was arguably better than what we've got now), but simpler is almost certainly better. Go back to putting payloads on big rockets, and work back up to complicated systems, once we've got a better handle on what we're doing. (For example, you could perfectly well use rockets to build a space station that would provide a platform for in-flight maintenance on Shuttle-like craft. Once you've got that, then start working on space planes.)

Of course, while we're at it, we should come up with some sort of program that actually makes progress toward a reasonable goal. That's the point of President Bush's new proposal for a base on the Moon, and also more ambitious things like Robert Zubrin's "Mars Direct" proposal. Space colonies are a perfectly reasonable long-term goal, but if that's what we're going to try to do, we ought to be trying to head in that direction, as opposed to noodling around in low Earth orbit.

I should note right up front that, like most people who have commented on this, I doubt that the Bush plan will turn out to be a Good Thing in the end. Not so much because I think it's inherently a bad idea as because it's being put forth by the Bush team. To date, I have not been impressed by their sincerity, competence, or good will, so I have grave doubts that this is actually a serious plan that will really improve NASA, as opposed to a publicity stunt, or a disguised plan to funnel yet more money to wealthy Republican donors.

In terms of laying out a reasonable plan for the future of space exploration, I actually think the Bush proposal is remarkable for its lack of grave conceptual idiocy. As this is somewhat at odds with the conventional wisdom among blog commentators, I should probably expand on that, and I will. In another post.

Posted at 11:11 AM | link | follow-ups | 5 comments

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