The New York Times is commemorating the 50th anniversary of Sputnik with a huge clump of articles about, well, space. I'm a little surprised that I haven't seen more said about these-- they turned up in my RSS feeds on Tuesday, but I've been both busy and slightly ill, and haven't gotten around to blogging them until now. I guess it's further evidence that space is no longer inherently cool. That, or there are just too many damn biologists on my blogroll.
Anyway, there's a bunch of retrospective material that I didn't really bother with, along with four pieces with more of a current scientific emphasis: Kenneth Change debunks myths about spin-offs, and suggests that the real spin-off benefits are at a higher level than Tang and Velcro. John Schwartz looks at the future, and sketches out the prospects for private space flight. John Tierney offers a half-serious open letter to billionaires encouraging them to fund more space research, and also proposes funding space flight by means of a ticket lottery.
Those are all worth reading, but the one that really resonated for me was Dennis Overbye's wistful reflection on the dream of easy space travel:
I can think of many much worse ways than space exploration to put my tax dollars to work, but the space dream has been dead for me since the early 1980s, when I chanced to see a particular photograph of a shuttle launching. The photo was taken from a chase plane. It shows a tower of smoke rising upward from the Earth's surface, which is blurred by the haze of altitude and clouds. Near the tower's glowing top, like a pinhead on Jack's beanstalk, is the space shuttle, dwarfed by its own plume, roaring away as hard as it can.
There, on a pillar of violence, is your dream of transcendence, of freedom, of escape from killer rocks in the sky, boiling oceans or whatever postmodern plague science comes up with. Of galactic immortality.
That picture broke my heart. I'd seen rocket launches before and been appropriately chastened by the thunder and heat it took to break free of gravity, but I had never seen it from such a perspective. So much work for such a small step into the universe. How could this ever be routine, economical or safe?
That's not just a pretty piece of writing-- I think he's nailed it. There's a reason, after all, why "rocket science" is the paradigm of difficulty.
It's not just that rocket science requires math-- the math involved is just vector calculus, and can easily be handled by computers. The real point is that the whole project of rocket science is difficult and dangerous and very uncertain. As the private entrepreneurs currently dabbling in space flight are beginning to find out.
Gravity is the weakest of the fundamental forces, but it's still a gigantic obstacle. Getting anything into space, at the moment, involves strapping a really expensive payload on top of an enormous firecracker, and hoping like hell that it doesn't blow up too quickly. NASA's big and bureaucratic and slow, but that doesn't change the fact that lofting mass into orbit safely is a genuinely Hard Problem, and no amount of spunky entrepreneurial spirit is going to change that.
I think most space enthusiasts are far too quick to belittle the real achievements that we have made, probably because the Appolo program got really lucky, and made the process seem easier than it really is. There's too much time spent running NASA down, and not enough celebration of the great things that have been managed. The fact that we've got robots roaming around Mars at all is absolutely incredible, if you stop to think about what's really involved in that process.
And, for that matter, the fact that we've only lost two Shuttles and one Apollo capsule over the last fifty years is a pretty impressive record. That compares pretty favorably with the exploration of our own planet-- I suspect that more people died trying to reach the South Pole than have died going into space.
It's intensely frustrating to people raised on Heinlein and Clarke and Asimov, of course. Humans walked on the Moon before I was born, and there's a part of me that resents the lack of a permanent Moon base thirty-odd years later. But, as Overbye points out, if you step back and look at what's really required for that, the expectations of the Golden Age SF writers don't look all that reasonable any more.
Materials science may yet come along to save us, by making something light enough and strong enough to reduce or avoid the risks of rocketry. Or somebody may come up with a really compelling reason for manned space flight that will drive more people into the field-- fatuous blather about a "primal urge to explore" doesn't cut it. But for the moment, space travel remains a Hard Problem.
And I'll give the last word to Overbye:
There is no galactic immortality. Everything we are and have done, the whole Milky Way with its billions of stars, is eventually destined to be swallowed up in a black hole. Neither ourselves nor our works will survive the end of the universe, if dark energy eventually blows it apart, no matter what we do. All we own is the present, so it behooves each of us to live each moment impeccably, guided by whatever lights we choose. Speaking only for myself, while we are around we might as well embrace the light and the unknown, the violence and vastness that terrify us.
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It seems to me, as an interested outside observer of the space programs, that the problem is not so much rocket science as rocket technology. As you say, figuring out how much energy you need to put payload X into orbit Y is freshman-level physics. Figuring out how to build a lightweight turbopump that will operate over a temperature range from liquid helium to burning helium, a pressure range from sea level to vacuum, and has parts that are moving very, very fast, is very very hard, especially if you want it to not blow up more than once every ten thousand flights. It's the reliability requirements, much more than the physics requirements, that are difficult. You physicists have made amazing progress in the last 50 years, but the engineers have made pretty modest improvements in the ability to build complex, reliable machines.
But yeah, it kinda sucks that we're (personally) not going to get to go to the moon. :)
Harlan is right. "Rocket Science" is easier than the "reduction to practice" by actual engineering.
In refereed papers I've published on "practical robotic interstellar spaceflight" the rocket science as such is the relativistic multi-stage rocket equation -- tricky, but ultimately just algebra. The additional science is on the physical chemistry of the proposed fusion fuels (saturated solution of specific lithium isotope in ammonia, which Harry "Hal Clement" Stubbs told me was neat; or cluster of grapes with spheres of deuterium ice with admixed boron or carbon fibers, wrapped in lithium foil, with a specific design for sublimation cooling).
The data are solutions of the relativistic multi-stage rocket equations showing when instrumented stages arrive in the target solar system, and each gives data to midcourse correct the next.
The papers make pretty clear that all that remains is the engineering. Which, to separate a theoretical paper or science fiction story from a real technology, is everything.
I agree; the problem is not rocket science, but rocket technology. And as long as we use rockets, I also agree that we aren't going to be jaunting along to the moon for vacations any time soon, or possibly at time at all. Talk about sending men to mars is exciting, but basically an extremely expensive waste of time, money, talent and people for the foreseeable future. Let's explore space with the most efficient technology we have - robots.
I want my space elevator, dammit! It's been promised by everyone from Clarke to Scalzi, and I've got rights.
I want a space elevator too! But one that is more reliable than the elevator in my OSU Physics Research Building...
Great post and great quotes.
However, I don't think Apollo got lucky. It had its death accidents, mostly due to not prioritizing safety on the system level. (Using oxygen atmosphere.)
Similarly the shuttle system level was compromised for political (combining military and civilian needs, non-equatorial site, et cetera) and economical (side mounted rockets, segmented boosters, et cetera) reasons, and the deaths are again traceable to these root causes.
The new generation US crafts aren't as sexy but apart from keeping segmented boosters and the old site placement they adopt lessons learned. They join Russia and China in prioritizing robustness.
And so do the first generation commercial suborbital crafts. (The recent fatal accident is investigated as an industrial accident and doesn't seem to have to do with the lift system.)
Quite, but we also need to let people exercise their adventure and exploration spirit. The spiring tourist industry will hopefully kindle a revival in interest and willingness to spend.
Let me plug Mike Gray's Angle of Attack as the best popular account of the engineering and people behind Apollo. The budget and headcount numbers alone don't do justice to the sheer scale of the effort behind the rallying cry of "Man. Moon. Decade." The heart attacks and broken marriages as well as the lives lost are testament to their single-minded dedication.
I don't know that it's fair to call the Apollo program lucky.
Nobody significant is going anywhere significant in any significant volume or significant frequency unless somebody discovers a superset of extant physics. No concatenation of hardware can compensate for the inescapable ugly of climbing out of the gravity well.
A space elevator (beanstalk; Fountains of Paradise) is ludicrous. First, the minimum energy path from ground to geosynchronous orbit is not a straight line, it's a spiral. Second, any significant length of conductor from ground to orbit will vaporize the first time the magnetosphere billows (e.g., solar storms). Third, so what powers the elevator? Fourth, It's a nine day trip up at 100 mph... and NASA never conquered the space toilet.
I don't know that it's fair to call the Apollo program lucky.
The Apollo Program was... the Apollo Program. I've done some space-class work, myself, so I know what's involved. I don't think it's unreasonable to say that there was some luck involved, nor do I think that detracts in any way from the astonishing human effort it took. There is, really, no reason it can't be both, and every reason to believe it was.
Space-class work brings out a lot of paradoxes. It's the only job that, when I was done, I threw down the towel and promised never again. And then, when we started bidding on the next gen launch vehicle, I realized that if part of the system fell to our group, it's also the only thing that would push me into an Engineering Project Manager role, because I wouldn't want anyone to screw it up....
Related: a great post on how bureaucracy led to a very sub-optimal shuttle design.
"...how bureaucracy led to a very sub-optimal shuttle design"
Nearly all the second-guessing about the Shuttle takes for granted that it could have been a winner if only [X, Y, or Z] -- that it should have been possible to go in ~10 years from the 1970 state of the art to a robust, reliable, fully reusable system -- a "space truck" -- at 10% or less of 1970's $/kg to LEO.
Wrong: there was no way that was going to happen on any remotely conceivable budget -- no matter what NASA, the Air Force, or Congress/OMB did or didn't do. The entire history of aviation (and of complex, high-energy, high-performance vehicles in general) tells us that it takes many design iterations -- and more important, many many flights feeding back into successive iterations -- to get anywhere close to that "sweet spot" combination. At the same time, markets for access to LEO would have had to grow by several orders of magnitude to support the flight rates needed to justify all that upfront investment. All that was (and remains) a qualitatively different, as well as quantitatively much greater, challenge than Apollo's "get 'em there by 1970, never mind an affordable or sustainable infrastructure."
So the real problem wasn't this or that design choice for the Shuttle: it was the belief that reusable, cost-effective access to orbit was essentially the same kind of task as Apollo, one that could be achieved inside a decade with what would be in effect a version 1.0. What's sad is not that the STS we got didn't achieve it (nothing could have), but that
(1) it was declared "operational" after four flights, and ever since has sucked up so much money that there's been no version 2.0, 3.0,...N to make incremental progress toward 1970's targets
(2) so many still cling to the faulty underlying assumptions, although in many cases they've transferred them to New Space start-ups. Cheap, reliable access to space is going to take a lot of designs, a lot of flights, a lot of money -- and therefore a long time -- no matter who does it.
It's a little off topic, but there was a book written more than 20 years ago by a science fiction writer who worked as a PR man in the military/space contractor business. I can't remember his name. He was writing about how wonderful missile defense would be, and how we would put up an orbital defense using the Shuttle, launching roughly once a week for a year. I can't really recommend the book unless you want a long dip into the absurd.
It would have to be absurd. MDA (previously BMDO which started as SDIO)doesn't have any plans to launch anything using the shuttle fleet.
Most of MDA is relocating to Huntsville, AL to be closer to Redstone and NASA MSFC. I'd like to say it's because they build and test rockets there, but it's mostly because keeping funding meant giving jobs to a state that a key Senator hails from.
Monte, the perspective on the difference in difficulty of task is interesting. I always suspected the political compromises that made the largest problem, with the direct savings (technical compromises) the second, and the non-development a distant third. But you are probably right that if the goal is a more affordable system it is a monumental task.
I was sort of assuming a safe and reliable system was the largest goal. But economy will remain a large concern.
Chris, that was worse than I suspected. :-(
Torbjorn: yes, it's the "affordable" that makes all the difference. To build -- cost no object -- a few machines that can perform an extreme task, one time each, is one thing. That can be accomplished with sufficiently careful "clean sheet" design.
But to create an affordable, robust system that can perform the task over and over requires exploring a much larger volume of engineering/economic trade space. To do that there's no substitute for accumulated experience, and lots of it. People wonder why space technology has advanced so much less in 50 years than aviation did; consider that by 1908 there had been more flights than there have been orbital launches since 1957.
Hello,
I think that the missing piece in all this discussion is that although NASA has not done "huge" projects since the Apollo and shuttle programs (if you consider Spirit and Opportunity little) Sputnik's greatest legacy is what we are enjoying right now: satellite communications!
Sputnik ushered not only the Apollo program and the shuttle missions, it also directly led to Telstar, Anik, EchoStar, GPS, GOES, Glonass and countless other satellites that are orbiting us right now. Just imagine if we did not have satellite communications right now. In some aspects we would still be stuck in the 1960s having to send major world news stories with dinosaur methods. GPS would be impossible, and our satellite TV universe would not exist.
My greatest fear is that we are taking satellites so much for granted, few will report on them (or their anniversaries) in any detail, except for stuffy history lessons we have heard for years. VIA SATELLITE NO LESS! How are we celebrating Sputnik's 50th anniversary? Are we going out and observing space and wondering about it? No, we are attending stuffy lectures, symposiuims and watching documentaries: AGAIN!; GROAN!
The way I am celebrating Sputnik's 50th anniversary is to single-handedly detect 1,957 individual satellites in the 2007 year. That is 1/5 of the current total satellite population! Since January 1, I have seen 1,650 satellites with my own telescopes and CCD camera: more than any astronomer has single-handedly done (to my knowledge). No, I can't launch my own satellite for this anniversary (I wish I could), but I can do the next best thing and actually detect as many of them as I can.
My website has a log of all the satellites I have observed this year, images, plus what I have observed, including tumbling characteristics for some of the inactive ones.
Feel free to look around!
www.castor2.ca
Mike.
But a "robust system that can perform the task over and over" is what I expected as priority. (Then again you have the fact that an expensive system won't be as much tested. But that is often a second order effect.)
It is "affordable" that makes the largest difference according to your previous comment.