For this baby boomer who grew up in the Cold War, the world has gone bizzaro. Here is Jeffrey Manber on Russian TV defending the capability of commercial companies to design and fly manned rockets and disputing Alabama politicians who are attacking such companies and claiming that only a government agency can do such things. The irony is manifest when Jeffrey notes that said agency will be paying a Russian company to launch its astronauts.
Heads are exploding all over the place.
Those activities _did_ come out of the U.S. space program, or rather the later contributed enormously to the former.
Not out of the manned space program. And many of them came out of the military, not NASA.
Do you have any idea how silly the above statement is? I could legitimately accept your concession of defeat in the debate based on it alone.
Before I “concede”, allow me to rephrase my words as a question. What has NASA done in the past 30 years to contribute to “weather prediction, national security, communication, and agriculture and geological industries by orbital observation”? You’ve already admitted that you can’t answer that question. Anything other than a concrete answer is touchie feelie, unaccountable crap.
It’s not just you. I’ve run into many such vague excuses (doing it for “Science”, international cooperation, inspiration of the youth, spinoffs, etc). All I can say is that if one cannot tell whether the program generates a net benefit or not, then it’s not good enough as a justification for an expenditure of public funds.
What has NASA done in the past 30 years to contribute to “weather prediction, national security, communication, and agriculture and geological industries by orbital observation”? You’ve already admitted that you can’t answer that question. Anything other than a concrete answer is touchie feelie, unaccountable crap.
I’m no big defender of NASA but I do believe in giving credit where credit is due. Over the years, NASA has done a lot with different unmanned satellites in several of the areas you mentioned.
Communications Satellites:
NASA led the new wave of communication satellite technology with the launch of Advanced Communications Technology Satellites (ACTS) in 1993. ACTS pioneered the use of spot beams, on-board storage and processing, and all digital transmission, which combined made a successful communication satellite constellation more feasible. Each of these innovations serve a certain technological purpose that makes and internet in the sky more likely.
Spot beams subdivide a satellite’s footprint which allows the satellite to use its portion of the spectrum more efficiently
On-board storage and processing allows for inter-satellite communication and the caching of information until a spot beam finds its target
All-digital transmission allows a satellite to incorporate error codes into its signal which helps to overcome rain fade.
Agriculture, geological and national security
Landsat images are used for many things. They help with agriculture, natural resource exploration, and yes, with national security. It helps to know agricultural and geological stuff about other countries, too.
The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey. Since 1972, Landsat satellites have collected information about Earth from space. This science, known as remote sensing, has matured with the Landsat Program.
Landsat satellites have taken specialized digital photographs of Earth’s continents and surrounding coastal regions for over three decades, enabling people to study many aspects of our planet and to evaluate the dynamic changes caused by both natural processes and human practices.
Weather
NASA did the experiments that led to the successful GOES satellites. GOES satellites are owned and operated by NOAA but NASA helps with the procurement.
The success of the meteorological experiments carried aboard the ATS-1 and -3 satellites led to NASA’s development of a satellite specifically designed to make atmospheric observations. SMS-1 and SMS-2, operational prototypes, were launched in 1974 and 1975. SMS-1 and -2, and GOES-1, -2, and -3 were essentially identical. They carried instrumentation for visible and international remote imaging, collection of data from automated remote platforms, relay of weather products (WEFAX), and measurement of a number of characteristics of the near space environment.
None of these have anything to do with manned spaceflight but NASA did have a hand in advancing all of those areas.
Rick Boozer – Thanks for that info. However, there is still benefit in having another approach to fusion being tried out. If one of them doesn’t work, then the other may.
I stand by my comment about tokamaks. They are costing billions of dollars, pounds, euros and yen; and if tokamak ever does work, it will end up as units the size of a ten-story building or greater, creating more nuclear waste than a fission reactor does. Aneutronic tokamak fusion is so far out there that it is essentially impossible; for one thing, the temperature for that sort of fusion is about half a billion degrees. I believe the magnetic field strength needed is orders of magnitude greater than for deuterium and/or helium-3 fusion, too.
You want a pipedream? Then consider; Back to the Future’s “Mr. Fusion” is actually not completely impossible. Of course, fusion power in units that small would turn the economy upside down. So did the Industrial Revolution.
Fletcher: the magnetic field strength for d-3He fusion in a tokamak is not enormously greater (remember, the fusion rate in a plasma at constant temperature and composition goes as pressure^2, and pressure goes as B^2). However, d-3He is 50 times less reactive that DT, and there’s more pressure from the extra electrons (since each 3He adds two to the plasma). Given that even d-t fusion is economically marginal at best, d-3He fusion in tokamaks is pretty much out of the question economically.
The thing about Polywell is it could power a rocket to Orbit by cooking hydrogen, not just act as a power source for a VASIMR type system.
You sure about that, Mike? I am quite willing to believe that either electrostatic (Polywell) or inertial (Focus, AFAIK) confinement fusion can have the geometry changed to make them into rockets; I’m considerably less sure that getting a 1G+ thrust out of them is possible.
In any case, a ground-launched fusion torch ship runs you into the truth expressed as the Kzinti Lesson.
Paul: Thanks for the details of the reaction maths, which I suppose I could have Googled. What you have said makes the point even better than I could. If D/He3 fusion is impossible, then proton/B11 must be doubly impossible. Another point against D/He3 is that one of the fuels is vanishingly rare. Yet another is that side reactions are quite common in a plasma containing D, and most of them create neutrons. If you are going to run a fusion reactor that uses ultra-rare fuel and produces large amounts of radioactive waste (by neutron absorption in the vessel) then why not just build a fission reactor instead?
D-3He isn’t necessarily impossible, it’s just looking impractical in tokamaks. Tokamaks have fairly low beta (ratio of plasma to magnetic pressure), and power/volume goes as beta^2.
For burning d-3He, an idea that looks considerably more promising to me is the levitated dipole. This configuration has, at least in theory, the ability to do “3He-catalyzed d-d fusion”, where the tritium from d-d fusion is removed, allowed to decay to 3He, then injected back as fuel. Reactors based on this concept would still be very large, but the coil would be on the inside, not the outside.
Btw: the levitated dipole idea was proposed by a guy at Bell Labs (Hasegawa, I think) after magnetospheric data at Jupiter was returned by space probes. He observed that turbulence in these configurations drives plasma inward, rather than outward, leading to a naturally peaked density profile. The idea can truly be thought of as a spinoff of the unmanned space program.
Fletcher,
http://www.signallake.com/innovation/Inertial_Electrodynamic_Fusion.pdf
Paul – Precisely. The more I think about it the more I dislike the idea of tokamak fusion – huge neutron flux in most of the reactions that might actually work, and the holy grail 1H/11B fusion reaction is so difficult you might as well call it impossible.
Mike – Hmmm… From my limitied reading of that article a 1G engine might just be possible. However, who are you going to trust with a fusion torch-ship with an exhaust temperature of a hundred million degrees or more and significant density? I refer again to the Kzinti Lesson.
Perhaps the best way to space is to use hugely inefficient chemical drives to get into space, use a linac on the Moon/asteroids to get raw materials, and build a beanstalk. Carbon nanotubes are just about strong enough. Perhaps this is the real “killer app” for nanotech.
‘You’ve already admitted that you can’t answer that question. Anything other than a concrete answer is touchie feelie, unaccountable crap.’
Sorry, but that’ s just not good enough. The real world _runs_ on complicated, impossible-to-measure-precisely gray areas.
NASA has gone off the rails in the last 30 years, no question. But the space program is not just NASA, ALL space activity done by the government, whether NASA, DoD, or any other branch is part of the space program. It all feeds into the same thing.
As I said above, I personally think creating NASA was a mistake in the first place, space activity started out in the armed services and that’s probably where most of the national/governmental activity in space should have been. The reasons for creating NASA were more political than practical. That said, NASA worked superbly in its early days, and it wasn’t the only institution to go catatonic in the 70s. That was part of a much larger cultural problem that goes far beyond space exploration.
Also, there’s no hard-and-fast distinction between manned and unmanned space flight in terms of impact. The technologies developed for one feed into the other, and the people pushing ‘use robots instead of people’ the hardest are precisely the one who actually want to use _neither_ and are playing one group against the other to undercut both.
This last bit of political naivete has haunted space exploration for decades.
‘Why I don’t necessarily disagree, HC, I think you’re tilting at windmills with the Heinlein thing.’ — Karl Hallowell
It isn’t Heinlein I’m knocking, or SF generally. Rereading my post I can see where it might come off that way, but what I’m really getting at is that space enthusiasts can be their/our own worst enemy at times.
It’s hard to point out hard-dollar justifications for manned space exploration. That isn’t surprising, exploration historically _usually_ runs in the red for long periods at first. A good historical case can be made that the North American colonies didn’t really pay for the effort expanded in Europe to found them for _decades_ after they were self-sustaining, and the benefits were (as often) diffuse even though real (though tobacco was hugely profitable after a while).
Space enthusiasts have tried to come up with commercial/economic justifications for it, ranging from the plausible to the silly, and sometimes it gets off into la-la land. I hate to sound so condescending or harsh, but I dont know how to avoid it when faced with lists of ‘justifications’ like solar power satellites, Lunar helium-3 mining, or O’Neil habitats, and these keep getting offered up.
Imagine trying to raise capital for a business plan based on power technology that _might_ someday work, and might not, and IF it works _might_ be economically competitive with existing power sources, IF the source of supply of a rare fuel can be made accessible, this last in turn being based on the unanswered questions of whether the material can be mined using untried techniques in an unfamiliar and implacably hostile environment at a cost of less that a gazillion dollars a kilogram.
That’s Lunar He-3 mining. SPS is no better. In order for it to become competitive with coal and fission, not just one huge unanswered question hangs out there, but dozens. Nobody sane is going to commit hundreds of billions, or trillions, of collars of capitol based on that.
And that isn’t the worst one. He-3 and SPS actually sound economically rational compared to O’Neil’s fantasies about space habitats.
Speaking _as a space enthusiast_, the best thing we can do for our cause is to lay these ‘justifications’ to rest.
‘Sure it sucks when you have to deal with someone who thinks we should be implementing Star Trek technologies like warp drives and teleporters (yes, they are out there), but you also get the people who make the satellites and prep the rockets.’ — Karl Hallowell
I know, and don’t get me wrong. There’s nothing wrong with dreams, they’re the fuel that drive most human achievements. But your point about the hobbyist bias on railroads is relevant, and it most _certainly_ applies to space exploration, in both directions.
NASA and their military kin are biased against space enthusiasts for many of the same reasons you listed about the railroad hobbyists, some good and some bad. The enthusiasts bring _some_ of it on ourselves when we forget political and economic reality or bring fiction into fact too much. OTOH, NASA and its kin would do well to remember that without the political support of the enthusiasts, their budgets and even organization survival would be in serious jeopardy.
Many in the professional side of space work privately suspect that the enthusiasts live in a fantasy world of Star Trek and Star Wars, and sometimes the enthusiasts can give that perception encouragement. For example, the possibly ancedotal story of supporters of NASA showing up a Congressional committee hearing in Trek costumes. Even if that story is just an urban legend (I don’t know), things _like_ that have certainly happened.
Space enthusiasts need to be a lot more familiar with practical politics and economic reality, and more realistic about what is technologically possible in the near future. O’Neil Habs, he-3 mining, etc, that’s trying to run before we’ve learned to properly crawl. Likewise, a libertarian-style large-scale private space industry isn’t going to happen anytime soon, barring major technological breakthroughs. It just simply costs too much.
‘None of these have anything to do with manned spaceflight but NASA did have a hand in advancing all of those areas.’
Oh, but there are connections, one practical, one political. The practical one is that technology is not compartmentalizable, R&D done for space flight applies to both manned and unmanned work, the feed back and forth.
The political one is that the infrastructure, governmental and private, that brought about the development work for the unmanned satellites came into being in much in response to Kennedy’s Lunar project. Without Apollo, the unmanned projects would either not have happened or taken longer, since the background would have been absent.
This is the flipside of an old technique of those who want to transfer resources out of space entirely: play the manned against the unmanned factions in NASA (and elsewhere), and use the disputes to defund _both_, since they both do such yeoman’s work in building the case against each other.
Fletcher,
The concept is called the arc-jet from hell.
It uses an electric arc to heat the propellant gas.
A good historical case can be made that the North American colonies didn’t really pay for the effort expanded in Europe to found them for _decades_ after they were self-sustaining,
Actually, the length of time after 1492 until exploration in the New World made a net profit was shorter than the time the “Space Age” has already existed.
‘Actually, the length of time after 1492 until exploration in the New World made a net profit was shorter than the time the “Space Age” has already existed.’
i.e. decades.