Slashdot Mirror
Homer Hickam Speaks Out For Fission Rockets
jonerik writes: "Former NASA engineer Homer Hickam (perhaps best known for his 1998 memoir "Rocket Boys," which was turned into the 1999 motion picture "October Sky") has this article in Technology Review in which he advocates that the U.S. revive its nuclear rocket program of the '50s and '60s, arguing that nuclear-powered rockets are the only realistic way of opening up the rest of the solar system - particularly Mars - to human exploration."
He is 100% correct in his assessment that nuclear power is our only currently viable option to explore the rest of the solar system.
Unfortunately, people are so freaked out about anything with the word "nuclear" or "reaction" attached to it the only way they would ever put a dime in it is if it was called "The Wonder Drive" or "Warp Drive". The really sad part about that is nuclear powered rockets really wouldn't be that dangerous. The most dangerous part about them would be getting the fuel off planet, which is not as dangerous as it sounds.
Beer Die is the game of champions Learning To walk my own path.
What sets this apart from most arguments for space exploration (at least in the popular media) is that he argues based on a need (energy) rather than talking about exploration and science for its own sake.
** The opinions expressed here are my own, and do not reflect those of my employers - past, present, or future**
Nice to see an old-timer get a little coverage on /., but he really covers no new ground in that short article.
The major objections then, as now, are:
- What happens if fission powered rockets crash? Instant nuclear disaster, unless the containment vessel holds (and it might, but the public will not be convinced it would).
- Other countries fears that fission powererd rockets are actually orbiting nuclear weapons, able to be dropped on them at will. And again, even if they weren't bombs, orbiting fission rockets would be nuclear weapons: all you have to do is build the containment vessel so it can be blown apart on impact via conventional explosives, leaving a cloud of contamination.
I don't predict these space nukes are coming any time soon. Better to invest in laser propultion and linear magnetic launchers.
The reactor shielding required for a manned spacecraft is pretty large. There isn't any particular mass savings through using a nuclear power source... most of the mass for a deep space mission is reaction mass, and the specific impulse developed by a nuclear rocket is only about 2 times that of a chemical rocket... reaction mass savings ends up being on the order of 75%, but this is offset by the increased payload/structural mass.
Now, if someone could finally get fusion rockets to work, I think we could finally go someplace. But I am skeptical about using fission for manned missions.
forget mars... i wanna go to Ferenginar... all the women are required to be naked. they're ugly, yeah... but they're naked!
Incidently, "October Sky" is an anagram for "Rocket Boys".
--
The internet is the greatest source of biased information in the history of mankind.
Whilst nuclear is one option to get us out there, particularly to the furthest planets, I don't agree that this is necessarily the way to go.
Putting the supposed issues of launching nuclear rockets to one side, all of the issues we know of will be solved by using the existing resources of space, rather than trying to launch every little thing from the earth. Right now we are doing the space equivalent of driving from East to West coast America, whilst carrying all our gas with us for the whole trip. Ever heard of gas stations?
NEOs and the moon have plenty of fuel for us to use, and if you refuel in space, the maximum distances we can go are enormous.
The other issues also become non issues. Radiation? A few tonnes of shielding isn't a problem if you have enough fuel. Gravity? Spin your spacecraft on a tether, and simulated gravity is plenty good enough [the only reason that this isn't proposed right now is mass constraints, also they want zero-g in the ISS for example]. Again, use non terrestial sources for materials, and most issues are gone.
Nuclear is an entirely safe and reasonable approach. But it's not a necessary one. And politically there are huge issues; for what are mostly dumb reasons. But we have to deal with dumb reasons, held by misguided people in life.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"News flash: Women here can be naked, too, if you do stuff like listen to what they say. Or at least pretend to, with an understanding look on your face, while you visualize them being naked.
:-)
Try it sometime
Marc Siry || interactive media professional, motorcycle enthusiast ||
Here is a link to that : here
Anyway, nuclear rockets are a great idea. A better one, you may have heard me harp on this before, is VASIMR. It is a plama rocket with a nuke power source. It will be around ten times as efficient as the nuke rockers. However, the VASIMR, unlike the nuclear rocket, it does not have enough thrust to launch from earth. It is more a slow and steady engine that runs for weeks instead of minutes. But the burnout velocity of a VASIMR can be vastly higher than a chemical rocket.
The nuclear rocket can provide cheap, efficient space launches with not too much radioactive fallout. In fact, if a nuclear rocket using helium as a propelent will produce no fallout at all. Since a nuclear rocket is about twice or three times as efficient as a chemical rocket, the amount of fuel you'd need would be slashed dramatically. A nuke rocket launch might only use 10% or less of the fuel that a conventional booster would.
It's under R&D.
It ionizes hydrogen with microwaves an then accelerates them with magnetic fields. While it doen't provide thrust like a chemical rocket, it certainly has many, many times more thrust than a ion engine. It has some oomph to it. For cheap launches, you really need somthing like the x-42 scramjet spaceplane. That would cut costs of launching by a factor of 10 with no giant lasers.
VASIMR will get a specific impulse of 30,000 seconds compared to 500 seconds for the shuttle's engines. A specific impulse is the number of seconds 1 kg. of fuel could produce 1 kg. of thrust. The specific impulse of the VASIMR is 60 times better than the shuttle. That is many times better than the ~1500 seconds you'd get with the nuclear rockets.
That would allow cheap interplanetary voyages anywhere in the solar system, using very little fuel. Using these engines, you could get to Saturn in less than a year. It would also allow slow intersteller trips of around 1% the speed of light.
Also, VASIMRs could be easily, cheaply, and quickly refueled for more missions.Interplanetary travel could become cheap. I bet each ship would cost around 5 billion dollars initialy. After that, it's cheap. After each trip, an X-42 could come and restock the ship with fuel and supplies. That would only cost around 50 million. We could send tens of thousands to colonize Mars.
BTW: On this article, it says the VASIMR gets 10,000 seconds. It can reach 30,000 with further development.
Read about the VASIMR here
--
If you don't understand any of my sayings, come to me in private and I shall take you in my German mouth.
You're missing a couple of critical points:
In short, there are huge advantages to a nuclear rocket over a chemical rocket. Check out NERVA and NIMF, the two best treatments of the subject.
-- Jeff Paulsen
As a uranium producing country, Australia has seen a number of 'mishaps' in relation to uranium mines. Admittedly, most of them have been relatively minor, but they demonstrate that no human activity is 100% failsafe, and the potential for massive disaster is huge when compared to other forms of energy production, fossil fuels included. Of course, this does not diminish the need to find alternatives to fossil fuel sources, they are dirty and finite (ie. unsustainable). Nuclear energy is not an appropriate response, though.
Also, beyond the production and disposal of nuclear material, what happens when something goes wrong with the rocket itself? Could you imagine a nuclear version of the Challenger disaster?
I'm as much of a technocratic utopian as any other /. reader, but even I realise that the use of technology, and its impact on society, is more important than any geek factor.
Thats only assuming that you use the nuclear rocket part to take off. This is unlikely. A more likely case is it will be lifted by manual methods, piece by piece, assembled in orbit and then operated a safe distance from the earth. Even if these parts explode in takeoff it will not have any real radioactivity risk assuming that it uses normal fuel (ie uranium, not plutonium) since the half-life of U-235 is almost a billion years and U-238 is billions of years (longer half-life means less radioactive and billions of years means very, very small radioactivity). In newly built nuclear power plants you can walk around near the reactor without any radiation risk due to this fact. Of course once you start up, it has radioactive daughters and transuranics that make it radioactive.
Suddenly, the hairy finger of a familiar monkey tapped me on the shoulder. It was time.--G. T.
Nuclear is practically a dirty word. Just stick your head out the door and say it, and in 5 minutes you'll have at least 5 hippies protesting outside. They won't know what or exactly why they're protesting, but it has the word "nuclear" attached to it, so it must be bad.
It's the same way with health nuts and the word "chemicals" though they don't protest it, they just condemn it. Just walk up to someone in a health club, and ask him, "Do you know how many chemicals you have floating around in your body?" and watch him get a disgusted look on his face like you accused him of having herpes. Or ask some clerk at a health food store, "How many chemicals does this have in it?" and laugh at his ignorant @ss when he tries to claim there aren't any.
BlackGriffen
Homer Hickman:
"During his long NASA career, Mr. Hickam worked in propulsion, spacecraft design, and crew training, and won many awards including the Astronaut Office's coveted Silver Snoopy award for his outstanding support of the astronaut corps, and a special commendation for overall excellence from the Director of the Marshall Space Flight Center. His specialties at NASA included training astronauts on science payloads, and extravehicular activities (EVA). He also trained astronaut crews for many Spacelab and Space Shuttle missions, including the Hubble Space Telescope deployment mission, the first two Hubble repair missions, Spacelab-J (the first Japanese astronauts), and the Solar Max repair mission. Prior to his retirement in 1998, Mr. Hickam was the Payload Training Manager for the International Space Station Program."
Mike Eckardt:
"Like many of you, I wanted to be an astronaut when I was young. It wasn't the glamor of a high profile, high risk job. It was the adventure. I lost that dream sometime during my teen years, when I realized that I wasn't enough of a Superman to join America's astronaut corps. But hope springs eternal. With the increasing availability of space flight in the 21st century, and the advent of a commercial tourist industry in space, I may yet manager to make my way into the high frontier."
Thanks for your input Mike. We'll get back to you.
-Rothfuss
Oh, you mean like Chernobyl? Not to make light of 100 or so deaths, but there are worse things in the world. It's hard to get worse than Chernobyl: Big core with high burn-up (that's lots of fision products from running), Zero containment, chemical explosions and fire at ground level.
Or perhaps you were thinking of all of the thousands of above ground nuclear bomb tests that the people have performed?
- Other countries fears that fission powererd rockets are actually orbiting nuclear weapons, able to be dropped on them at will. And again, even if they weren't bombs, orbiting fission rockets would be nuclear weapons: all you have to do is build the containment vessel so it can be blown apart on impact via conventional explosives, leaving a cloud of contamination.
Holy Armagedon, Batman! Do you think that this is a more practical means of nuking your friends than the tens of thousands of purpose built warheads lying around?! What shall we do?
I suggest we quit fooling around with bullshit fears and get some good use out of Nuclear technology. Projects Kiwi and NERVA were technical sucesses killed by ludite nonsense. We can go to Mars, we can exploit the solar system and we should do so. The sooner the beter, population expands geometricaly. We can use nukes to solve our problems peacefully, or we will use them the other way as we run out of exploitable resourses here. Chose your children's future.
DMCA, Hollings, Palladium. What might have sounded like paranoia is now common sense.
The best a chemical rocket can do is get up to speed (burning up all its propellant in the process) and then drift to its destination, like a car coasting down the highway with its engine off. What's needed are space drives that will provide a constant velocity.
As any high school physics student will tell you, burning up your fuel and then "coasting" the rest of the way means that you're at a constant velocity. Velocity is a vector, with two components: Speed and direction. In space, there's no (significant) drag or friction, and so your velocity is constant. If you were to keep burning fuel, you would keep accelerating (assuming an infinite amount of fuel) which anybody will tell you is not a good thing when you eventually want to stop.
I see no reason to listen to somebody talk about physics when he clearly has no respect for the language.
Nuclear does scare folks. The medical imaging of NMR (Nuclear Magnetic Resonance) got changed to MRI (Magnetic Resonance Imaging) because people were freaking out about the 'nuclear' part. Even though it was passive reading of nuclear states, not actively nuking patients.
l ea r.html
There's a good writeup on:
http://www.urbanlegends.com/science/mri_not_nuc
The "nuclear rocket" folks could take a page from their book. Call this "water rockets" or such and downplay the nuke, upplay the 'tea kettle' method (or what have you).
A.
i have found that many of those "hippies" are very well informed about how nuclear reactors work.
I learn more about nukes from then than from the average government or industry nuclear supporter.
Yes. Slow intersteller trips. The ship would probably be passed en route by faster ships. However, it is an easy way to send huge quatities of materials to other stars.
.1 C would be nicer for fast manned missions or probes. That would mean 40 years to Alpha Centauri. That is doable, but would require an enormous amount of fuel. .1 C, you can use several different methods.
.2 C by a 10 gigawatt beam of microwaves from an orbital power station. Very easy to do, especialy if we have nanotech. .9999 C. The gold-foil sail would be only a couple atoms thick, and supported by a scaffolding of nanotubes. The sail would weigh only a few thousand tons. The payload could be a million tons. That sounds fantastic, but an extremely advanced civilization with nanotech and AI could easily do it.
.01 C like you can reach with the VASIMR would be excellent for intersteller resupply, or sending huge numbers of people for colonization.
To reach
1. Fission fragment sail or reactor.
Uses thin films of highly fissionable Americium as fuel.
The fission fragments from the nuclear reaction escape at very high velocities, propelling the ship very fast. You can't use plutonium in this setup because it cannot fission when formed into thin films. You need thin films for fission fragment propulsion so the fragments can escape.
This setup can reach a specific impulse of 1,000,000,000. 2,000 times more efficient than chemical rockets. However, this gets too expensive when you scale it up beyond a small probe. Americium is fscking expensive, millions of dollars per ounce.
2. Fusion
Fusion's great. Once power fusion reactors come on line, the fuel will be cheap.
There are several different fusion concepts. The closest to being realized is the ant-matter catalyzed fusion type. It blows up little fusion pellets at it's rear. This uses fusionable pellets of Deuterium and Tritium that are surrounded by uranium. A very small quatity of antimatter is fired at it. This starts the fission which then starts the fusion and causes the whole thing to explode.
This could be built in 20 years. Everything is here except the antimatter. You only need a few micrograms of antimatter. We could be producing that pretty soon. It could theoretically reach 200,000 seconds.
There are other types of fusion rockets that could reach 1 million seconds. These use magnets to confine the fusion plasma. Some is leaked out the back for propulsion. However, it's hard to build a self-sustaining fusion reactor. Plus the magnet weight (1,000 tons) would have to be reduced dramatically to be practical at all. That's about 50 to 70 years away.
3. Antimatter-matter
Efficiencies of 10 million seconds
A helluva long ways away. We don't know how to begin producing enough anti-matter.
4. Beamed energy
In the distant future, the best thing for fast intersteller flight.
Just a couple decades down the road, we could build Robert Forward's starwisp probe. It would be 6 kilometers wide and be made of a fine mesh. It would weigh 42 grams, if you can believe that. It would be easily propelled to
For manned flights, you need gigantic solar arrays around the sun. Here, I'll talk about a project for a Class 2 civilization. That means one able to harness the power of an entire sun. Say, 100 years down the road, we decide to have thin-film photovoltaics constructed around the sun. That would capture around 1 octillion watts. Anyway, autonomous self-constructing robots and nanobots would get the materails off a large asteroid and begin constructing this. Being very thin solar cells, you'd only need maybe 1,000 square miles of materials. After a few years, we would have a working Dyson sphere.
Some of the power, maybe a quintilion watts could be funneled into lasers and broadcasted to a giant gold-foil sail the size of texas or the US or even much larger. The laser would be able to propel it to
Anyway,
If you don't understand any of my sayings, come to me in private and I shall take you in my German mouth.
It is really annoying when some one arguing from authority (i am a rocket scientist, listen to me) gives you misleading information.
Nuclear engines are much more dangerous than chemical ones.
If a chemical rocket develops problems on ascent ground control push a button and blow it up.
What if that rocket has a shitload of uranium or plutonium on board?
We have sent nuclear material up in rockets withsome nuclear powered stelites but they have a really negligable ammount of radiactive stuff in them, compared with what is needed for a mission to mars.
And if you think that rockets do not blow up on ascent any more you have not seen NASA's record recently.
So there you have it - thats a risk that he did not mention although it is a very relevant factor. Now you may say - the risk is not that great, or it is worth it, but it should have been mentioned in an honest article.
And also the thing he said about getting energy from space is such BS. If he knows as much about nuclear power as he pretends to he should know that we have enough uranium to give us energy for a loooong time and nuclear powerplants are much safer than nuclear rockets.
To propose that we spend more money on NASA (with cutbacks already planned), the "nuclear fission" rocket may just be a pipe dream. It's hard to convince people that we need to explore space when the topic of the day is terrorism.
Well, they go hand in hand. The technology from space exploration affects our lives in thousands of big and small ways every day. The integrated circuit was first mass-produced for space exploration reasons. And it's a lot easier to peel my fried eggs off Teflon than it is off cast iron.
Any advance in getting the general public to get over their Three Mile Island and Chernobyl paranoia will require nuclear-powered triumphs.
Idiot hippy environmentalists speak of cutting dependence on (foreign) oil by moving to electric cars. That'd be nice. How do you intend to handle California's power crisis (remember, 2 years ago) when 10,000,000 Los Angeles commuters are plugging in their cars every night?
The very same environmentalists who scream about oil and air pollution are also at the mass rallies to ban genetically-modified agriculture. GM corn is probably the most economically feasible way, at this point, to make large quantities of methanol, which could replace gasoline very easily, simply retrofitting existing vehicles and infrastructure. These people also scream that we have to solve world hunger before we feed our cars. (My opinion? Theses savages are stupid enough to breed when they can't feed themselves, let alone their larvae. It doesn't take education or literacy to understand the problem; a below-average human intelligence should readily grasp the situation. It's not my problem, and I resent you attempting to make it my problem.)
Tidal/Solar/Wave power? Sure, they're neat science fair projects for the kiddies, but they're simply not capable of contributing substantially to our energy needs for the forseeble future.
Nuclear power is the only viable solution. And the proles have discarded it because they're too simple to understand that blaming nuclear power for Chernobyl would be like blaming gasoline for a car accident. Chernobyl, Three Mile Island and the vast majority of car accidents are caused by imbeciles, not the fuel source.
What's all this got to do with terrorism? Simple. The sooner we get off foreign oil, the sooner we can dig a moat around the Middle East and let them do their thing in isolation from the civilized world. And if funding NASA to build huge nuclear public-relations projects which will inevitably bring us other technologies as a consequence, I'm all for it.
Go ahead. Mod me down. But I'm right, and all the politically-correct simpering you might want to do won't change the facts.
Fire and Meat. Yummy.
I've read the World Health Organization's ten year report and I'd point to it if I could. Unfortunately, that one and a new one are not free information. Order it or go visit a library.
I'm not going to say there are no risks, what I'll ask you to do is weigh the risks of doing nothing. The shutdown of the US space program is a national embarassment. We beat up all the lions, tigers and bears. Even the baboons gave up (Appologies to W. Chruchill). The world is watching us and they expect results. We should show them that it is better co-operate and create new resources than it is to squabble over and destroy old ones. If we wait too long, we may no longer be able to afford the effort.
DMCA, Hollings, Palladium. What might have sounded like paranoia is now common sense.
First, there's the well-documented high failure rate of launch vehicals -about 5% for the US, 10-20% for rest of the world. This figure doesn't include experiments or tests.
Second, the atmospheric reentry of one lost rocket schlepping clicking-hot material up the well can lead to the atomization and dispersal of that material in the atmosphere, transforming the earth into a mutants' menagerie.
The Space Shuttle has experienced a lower failure rate than the rest of US launchers, about one in one hundred.
There was an uproar a few years ago, about the Cassini probe. That probe, containing over 32 KG of plutonium, was lifted by a launcher which, at the time, had a one in twenty failure rate, and was due for another.
Additionally, there have already been three catastrophic failures of launchers with plutonium-containing payloads, resulting in world-wide atmospheric dispersal of a hundreds of curies worth of plutonium.
Personally, I don't have a problem with the idea nuclear power or fission-powered space travel. But there remain serious development before it becomes considerably safer. This isn't a marketing campaign, you can't convince knowledgeable people with images of spouting teapots, not when life on this planet is at risk. Nor will risk management white-wash keep people from realizing there's a definite, likely risk that people will die from an accident. [I work in risk management.]
So, what's more important, do we need to do this now, now, now? Or can it wait a decade or three, until we have nuke power better figured out? My vote is to wait a bit.
Big Daddy, Johnny, Burp, Aunt Zelda, Scott, Slurp, Big Momma
Yup, just whip a handy-handy Sears Roebuck discount Dyson Sphere out of your back pocket, follow the directions, and you'll have your own private Dyson sphere in minutes, just like on the movies... no worries, mate! (-:
Got time? Spend some of it coding or testing
Actually (and very OT), you'd have a good chance of being right if you accused those health nuts of having Herpes too - 60-90% of the world's population has been infected with Herpes Simplex Virus 1, and it tends to kick around in a latent form. Furthermore, you could also tell them that 1% of their genome consists of viral inserts, and that therefore they are a GMO (sorta), but they might not thank you for it.
"What is freedom of expression? Without the freedom to offend, it ceases to exist." Salman Rushdie