Using Fusion To Propel an Interstellar Probe 155
astroengine writes "We've heard of nuclear pulse propulsion being the ideal way to travel through interstellar space, but what would such a system look like? In the 1970's, the British Interstellar Society's (BIS) Project Daedalus was conceived to fire pellets of fusion fuel out the rear of an interstellar space probe that were ignited using a powerful laser system. The 'pulsed inertial confinement fusion' wouldn't be 'vastly different from a conventional internal combustion engine, where small droplets of gasoline are injected into a combustion chamber and ignited,' says Richard Obousy, Project Leader and Co-Founder of Project Icarus. Now, building on the knowledge of Daedalus, the researchers of Project Icarus have prepared a nifty animation of a fusion pulse propulsion system in operation on the original Daedalus vehicle."
Or fission (Score:3, Interesting)
http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) [slashdot.org]">Project Orion from the 1950s
Re:Or fission (Score:3)
https://secure.wikimedia.org/wikipedia/en/wiki/Project_Orion_%28nuclear_propulsion%29 [wikimedia.org]">Project Orion from the 1950s
Fixed URL.
Re:Or fission (Score:2)
Oh, sorry. I've seen people explicitly "correct" a wikipedia link to use secure.wikimedia.org when nothing else was wrong with it (example here: http://slashdot.org/comments.pl?sid=2067194&cid=35708472 [slashdot.org] ), so I assumed that's what you were doing.
It's also good to hear I'm not the only one with no slashdot links working... that was driving me crazy.
Re:Or fission (Score:2)
Re:Or fission (Score:5, Interesting)
I read about this years ago, and also nuclear aircraft [wikimedia.org] more recently. a bit hazy on the rocket theory, but I was rather amazed they actually attempted airborne... the potential for fail is beyond ridiculous... like a B-52 doesn't make a big enough mess with just nuclear weapons [wikimedia.org], never mind a reactor on board...
Re:Or fission (Score:2)
Fun fact: there are currently numerous nuclear reactors in orbit around the earth.
No, not nuclear batteries. There are way way more of those.
Nuclear Reactors.
Re:Or fission (Score:2)
Actually, I googled for "orbiting bnuclear reactor", and came up with this [wikipedia.org].
So, it would appear that nuclear reactors have been launched from Earth, and that the core of at least one is still parked in "disposal orbit".
GP's "fun fact" might be more "fun" than most of us realize.
hey, I remember that! (Score:2)
Re:hey, I remember that! (Score:2)
Well, I think technically it would be "irradiated" ... there was no nuclear detonation or anything.
But, yes. :-P
Re:Or fission (Score:2)
It malfunctioned and later fell apart.
Re:Or fission (Score:2)
Those were in fact the satellites I was referring to. Guess I should have specified fission as well, I wasn't trying to refer to stars.
Re:Or fission (Score:2)
Keep in mind that at the time it was a question of how much risk is acceptable to protect the US/USSR from total annihilation. The Russians actually flew some of their aircraft and irradiated the crews, but they were desperate. In the end ICBMs proved to be the better option so nuclear aircraft were abandoned.
Re:Or fission (Score:2)
Well, I think the reasons for looking at nuclear aircraft maybe weren't all so silly as having the biggest, baddest stick on the block, although no doubt that was part of the attraction. A nuclear powered aircraft could take off at the first hint of an emergency, and remain aloft indefinitely, randomly cruising the vast airspace of North America virtually untrackable by the Soviets until the order came to attack. Then they'd be able to strike any point on the globe from just about any other point on the globe.
In other words they'd play the role we finally assigned to submarines.
Re:Or fission (Score:2)
As a interesting bit of trivia, nuclear aircraft are the primary reason why we have modern IFR rules [wikipedia.org]. The aircraft required so much shielding, the pilots could barely see out of the aircraft. So to allow for safer operation, they started with some simple procedures used by submarines and it has evolved to what safely delivers you to the ground today.
Re:Or fission (Score:4, Informative)
Reference? Airliners where forced to always fly IFR after a collision between two airliners over the Grand Canyon. http://en.wikipedia.org/wiki/1956_Grand_Canyon_mid-air_collision#Catalyst_for_change [wikipedia.org]
The NB-36 test plane only flew between 1955 and 1957. Since the Grand Canyon crash happened right in the middle of the test flights I would say that the rules couldn't have been put into place for the test flights. Also the NB-36 always flew with chase planes to warn the pilots about anything that in the area and as you can see from this picture http://www.aviation-history.com/articles/nuke-american.htm [aviation-history.com] the NB-36 did have a windscreen. Also the reactor was at the back of the plane so there would not need to be much shielding in windscreen area if any at all.
Re:Or fission (Score:2)
Remember, they had the very basics of IFR all the way back to WWII and night missions. But it was basically what submarines did using a visual reference to synchronize a timer. The nuclear aircraft required the creation of more formalized procedures which which look more like today's modern rules.
My information was from a documentary with the pilots who flew those aircraft and their statements about the fact THEY, and this program, were the origins of modern day IFR procedures.
You should also investigate the procedures which followed the canyon crash. They were minor changes to say the least.
Re:Or fission (Score:2)
They had IFR before WWII. Jimmy Doolittle made the first blind take off, flight, and landing back in 1929 https://secure.wikimedia.org/wikipedia/en/wiki/Jimmy_Doolittle#Instrument_flight [wikimedia.org] here is a brief history of the airway system that started around the same time http://www.centennialofflight.gov/essay/Government_Role/navigation/POL13.htm [centennialofflight.gov]
I have been an EAA member since 1978 and soloed in a 2-33 glider at 16 many years ago. I have been involved in aviation for a very long time and I have never heard a single reference to nuclear aircraft or submarines in reference to IFR flight. What documentary was this? I am asking for some hard reference because it makes no sense. The ocean is very large and the total number of submarines has always been pretty small compared to aircraft. You never have 100 subs coming into port on any single day. Not even during WWII. I doubt that you would even have 10 in a day. Before nuclear subs subs spent most of their time on the surface anyway. The would transit to and from their patrol areas on the surface because they had to use diesels to move any real distance at speed and they where actually more trackable on sonar when snorkeling than on the surface because more of the sound would get transmitted to the water.
Since the first nuclear submarine was not launched until 1954-55 It is far more probable that submarine operating procedures where influenced by IFR rules. And in now real way where they influenced by the single test aircraft with a nuclear reactor. Oh and as to aviation documentaries they are often terrible sources of information. You have no idea how many times I have seen crap on the Military channel or History channel that makes me want to beat people.
So again do you have any references? Some documentary isn't one and I can find no reference to what you are saying in any history of IFR fight I have access to. A lot of aviation practices have been derived form maritime practices but your suggestion that IFR rules where put into place because of the low outward visibility of nuclear bombers that where never built and submarines doesn't make a lot of sense and I can not find any supporting documentation.
Now in an interesting aviation to submarine cross over when the US built the first teardrop shaped sub named the Albacore which lead to the Skipjack class of really fast nuclear subs the navy used bimps to train the helmsmen. It was so maneuverable that it was much more like a blimp than any ship. Reference http://www.amazon.com/U-S-Submarines-Since-1945-Illustrated/dp/1557502609 [amazon.com]
Re:Or fission (Score:2)
http://www.merkle.com/pluto/pluto.html [merkle.com]
Re:Or fission (Score:2)
Re:Or fission (Score:2)
Re:Or fission (Score:2)
Re:Or fission (Score:2)
Oh, sure, you say that now.
Wait 'til it lands by a black smoker [amnh.org] and we get a Godzilla-sized tube worm or one of these [amnh.org] the size of an air-craft carrier. Then you'll change your tune!
And, yes, of course I'm joking.
Re:Or fission (Score:2)
Re:Or fission (Score:2)
Re:Or fission (Score:2)
You mean nearest star? Nearest galaxy to Milky Way is the Sagittarius Dwarf Elliptical Galaxy [wikipedia.org]; 70,000 light years from Sol. Not sure constant thrust (1g - 3g?) would allow us to reach it within 50-70 years.
Re:Or fission (Score:2)
Currently today Project Orion would be the ONLY feasible way we could travel to the nearest galaxy within a human lifetime
I assume you meant nearest star: as the nearest galaxy to Earth is twenty five thousand light years away, we're only going to be able to travel there within a human lifetime if we find a way of moving faster than light.
Physics our Enemy (Score:2)
Unless we figure out something that allows us to beat light speed even the nearest star is 4 years + away.
Re:Physics our Enemy (Score:3)
Thanks to relativity / time dilation, you can get close w/o breaking it, and (at least to the passengers), it'll seem like a lot less time overall. Still more than four years to the nearest neighbor, but a lot less than the monster number of years it would take as we see it.
Re:Physics our Enemy (Score:2)
Re:Physics our Enemy (Score:2)
Why do people say that so often? If we go 2 X c, do you somehow think that if we fly to Alpha Centauri and back we will arrive before we left? It is still 2 years there and back, so you will arrive 4 years later. Just because your light reaches the destination after you do, does not imply time travel.
Re:Physics our Enemy (Score:2)
Don't bother, they won't listen (Score:2)
even the nearest star is 4 years + away.
Don't bother telling them. People who think we'll be journeying to other star systems and colonizing them someday really have no appreciation of just how vast and empty space is. When I was a kid my ignorant teachers used to teach us that the next solar system was just beyond our own, and that one day we would be going there (along with cities on the moon, etc.). When I got older and began to learn from non-moronic sources, I realized just how silly that really was. Our fastest probes today take some 9 years just to reach Pluto. At that rate, it would take that same probe 120,000 years to reach even the nearest solar system--a mere 4.2 light years away.
And you're right, even if we were to come up with some incredible propulsion breakthroughs, it still wouldn't help all that much. If Einstein was right, near light speed is as good as it gets. And that would still make all but our closest galactic neighbors practically inaccessible.
For all practical purposes, we are alone--and will continue to be. But the dreamers don't want to hear that, of course.
Re:Don't bother, they won't listen (Score:3)
even if we were to come up with some incredible propulsion breakthroughs, it still wouldn't help all that much. If Einstein was right, near light speed is as good as it gets. And that would still make all but our closest galactic neighbors practically inaccessible.
Space is vast and using conventional propulsion tech, you are correct.
But it also would be looking at a bird and saying we'll never fly. Technology can greatly affect what is 'possible'.
Einstein also agrees that worm holes are possible so faster than light travel *is* possible by his definition. You don't actually exceed the speed of light, but you get somewhere faster than the light would have by taking a shortcut.
Are we anywhere near that sort of ability? of course not. But so far it isn't impossible either.
Re:Don't bother, they won't listen (Score:2)
Will just have to make our own aliens. Who's up for some freaky body mods so they can settle and start an Ayn Rand asteroid settlement. Within a generation or two; totally alien.
Re:Don't bother, they won't listen (Score:2)
I actually think that is the more likely possibility. If humans are able to genetically mod themselves in the future, they could easily end up creating post-humans that are much more strange and bizarre than any alien we've ever conceived of.
Re:Don't bother, they won't listen (Score:2)
Re:Physics our Enemy (Score:2)
Not quite so. We can't go faster than light, but with some energy we can make the travelling distance smaller, so we can get there in less than 4 years (on the traveler's reference frame).
Relativity is funny like that.
Re:Physics our Enemy (Score:2)
Re:Physics our Enemy (Score:2)
They roll up the windows and lock the doors as they fly by.
--
BMO
Re:Physics our Enemy (Score:2)
Sorta' like driving by a mucky, algae filled puddle; try not to get any on you.
Maybe we are the first... (Score:2)
Well, while "life" could be common, we might be one of the only "intelligent" species out there.
Intelligence is probably pretty rare because until it is very advanced it tends to be a detriment. Growing our brains is extremly energy intensive and needs many years. Even on earth life formed almost immediatly once the oceans formed but it took billions of years to get to us.
Plus, since both life and technology requier a wide variety of elements, it is unlikley that any star much older than the sun could have formed life. Every generation of star bumps up the concentration of higer elements, systems significantly younger will not have much material to work with.
Finally, we might actually be one of the smartest creatures out there simply because we have more energy available to us. Assuming that life needs liquid water, we can plot out the "Goldilocks" zone. When you map out Sols goldilocks zone you see that it extends from about 0.9 AU out to about 3 AU depending on the size of the planet (yes Mars could have water if it were larger). So we are just barely inside the Goldilocks zone which means we have more energy available to us than most habitable planets. This means that our ecology is likely to be more complex and more agressive than most.
Re:Maybe we are the first... (Score:2)
The down side is that advanced civilizations are more likely to blow themselves up and never get to the interstellar stage. Or that they either already existed and died out or we will die out before they develop.
The net result is the same isolation, but it doesn't follow that we are so unique that we're the only ones that ever have or will ever exist.
Re:Maybe we are the first... (Score:2)
No, I don't think we are the only ones that could or will exist. But I do think we stand a solid chance of being the first intelligent species.
This is because we have a very good energy balance on earth and it is unlikely that a planet like ours could have formed much before we did.
Re:Maybe we are the first... (Score:2)
We might actually be first though, or at least among the first crop of advanced civilizations. Mostly because of the age of the universe and the time it takes to form enough of the heavier elements that make life possible.
Re:Physics our Enemy (Score:3)
Unlikely, clouds of interstellar dust several light years across tend to get noticed, especially if they're that close.
Why Icarus? (Score:5, Insightful)
I really don't get the fascination with naming space projects after a failed attempt at flight. If there's one thing Icarus didn't do, it was "[build] on the knowledge of Daedalus!"
Re:Why Icarus? (Score:3)
If there's one thing Icarus didn't do, it was "[build] on the knowledge of Daedalus!"
As I remember the story, Iccarus did build on the knowledge of Daedalus (who built his wings), and flew higher than Daedalus.
Re:Why Icarus? (Score:2)
Also, while immensely unfortunate for Icarus, the story is one of triumph for science. The next revision of the wings didn't utilize wax. Now we can fly to space.
Re:Why Icarus? (Score:3)
Depends how you define "fail". His wings worked pretty well, too well in fact...
Re:Why Icarus? (Score:2)
.
Re:Why Icarus? (Score:2)
Go Team Venture!
Re:Why Icarus? (Score:2)
Never going to happen. (Score:4, Insightful)
"Nukular" hysteria will kill it.
Remember when we launched Cassini with a radioisotope thermo-electric generator?
"OH GOD IT'S GOING TO SPLODE AND KILL EVERYONE!!!111ONE"
Every time I see shit like that, I want to slap people.
--
BMO
Re:Never going to happen. (Score:4, Insightful)
any fear of radiation is, to use your phrase, "Nukular" hysteria.
Good job there of putting words in his mouth.
ich bin space nutter (Score:2)
Re:Never going to happen. (Score:4, Insightful)
Just a question.
Why on earth do you think that if someone doesn't relocated half way around the globe into completely different country with a different language and culture that they are a 'blowhard' and a hypocrite? (I actually had to look up blowhard, never heard that before... odd phrase). Especially when they were talking about a spacecraft launch? I mean this isn't even suggesting building a nuclear reactor, it's about a radioisotope thermal generator. Talk about projecting.
Aren't you really exaggerating it a little? If you were being honest, and seriously looking at what you think and what you're afraid of wouldn't you admit to exaggerating a little there?
So you're in a panic about Fukushima, awesome, but I fail to understand what this has to do with Cassini's RTG?
Obviously radiation is radiation, so that's scary, I mean it's not like there are different types like alpha, beta etc? Or things like alpha sources, like say the Plutonium 238 on Cassini's RTG can be stopped by a few cm of air, and in fact about the only way to be harmed by it is to ingest or breath it (I suppose if one of the RTGs from it hit you in the head if the launch failed it'd harm you but that's not really radiation). Or that it's insoluble unlike the iodine you're petrified of in local produce and fish so wouldn't really get out of the soil and so there's only a tiny window in which you could possibly get a tiny amount of it into you. But obviously that's really scary and will destroy everything.
The reason he wants to slap people who say things like
"OH GOD IT'S GOING TO SPLODE AND KILL EVERYONE!!!111ONE"
is because it's moronic and they don't have a clue, they're afraid it will destroy the world and when it comes down to it they're petrified of cancer and death and radiation == cancer.
People fear what they don't understand, people don't understand statistics, radiation and frankly technology and people do stupid things like try and compare a spacecraft launch like Cassini with an RTG on it with swimming inside of a nuclear reactor. Your exact response is stupid, sensationalist and not based in reality, just your fears of it. (Yeah I know, the swimming in the nuclear reactor was sensationalist, but seriously, it's a fecking tsunami hit area and you think they're on the beach swimming? Riiight, good to know your priorities)
Also, seriously you're suggesting drinking from streams in tsunami hit areas in Japan? If you do that I'm pretty sure radiation that might cause cancer 40 years down the road is the least of your problems, ignoring the possibility of things decomposing into the water and all the bugs you'd get that way I'm also pretty sure there's a pot load of toxicity from all the rest of the stuff washed on the land, like say oil, gas, and who knows what other industrial run-off.
As for increasing the chances of dying, yes it would, living in a tsunami hit area you're always going to have a higher chance of dying, I mean it's not the most healthy place in the world - I mean gas is carcinogenic, so any of that being around is bad and I'm pretty sure that cars didn't magically survive the wave intact, nor were their tanks empty. They don't have all the bodies removed yet, so they're going to decompose and potentially have a bunch of nasties in, things like rats are going to multiply it's just an unpleasant place to live.
And yes, there is an increase in radiation, pretty much all of it short lived - half lives of 8 days isn't too worrying if you're careful for a month, but to be frank the highest risk to anyone there isn't from the reactor, it's from everything else. There is a small, and unmeasurable risk due to the radiation from the reactor, whilst in the individual this may translate to death it's impossible to attribute that to the radiation from the reactor - you may have just had sucky genetics, or for some reason you used an antique tritium dial watch, or you spent too long flying around, or you had gas splashed on you at some po
Re:Never going to happen. (Score:2)
I didn't need any defending, but thanks. Really well written.
>If you really are that petrified about radiation and the possible implications for you in the future I suggest never getting out of bed,
Or eat a banana, or have to go to the hospital.
Heh.
And by the way, I would be more afraid of parasites drinking from any random stream than radionuclides.
--
BMO
Re:Never going to happen. (Score:2)
No problem, pretty much I agree with you which is why I wrote what I did but I'm glad you approved :)
I did like finding out how much radiation you got from eating a banana, or even just sleeping next to someone - it's entertaining. Told someone at work and they freaked no matter what they were told, or how small the radiation is....
Z.
Re:Never going to happen. (Score:2)
The original phrase I was objecting to was "Nukular" hysteria. The clear intent of the phrase was to cast anyone worried about nuclear power as being so ignorant that they could and should be ignored. This is an ad hominem attack http://en.wikipedia.org/wiki/Ad_hominem [wikipedia.org]. Instead of acknowledging that there are serious concerns, you set up a 'straw man' to make fun of. This is intellectually dishonest.
When I suggested going to Fukushima or Chernobyl I was not being literal, I was being sarcastic. My intent was to contrast your snide remarks with the real situation faced by people with the triple threat of earthquake, tsunami and nuclear radiation. Your ad hominem attack also denigrates those in real peril, even if you do not wish to admit it.
When I talked about being in the natural environment in Fukushima, I was pointing out that you have no personal concern about radioactive contamination in your day to day environment. There are millions of people who are faced with this uncertainty every day, and millions more who are now worried about eating contaminated food. Some of this is over reaction, but a lot of it is not. By you standard, they are all 'hysterical'.
What you call hysteria is a completely natural response when the public is lied to in a crisis. Both TEPCO and the Japanese government have denied the danger since the reactors were damaged. Their statements to the public have been continually wrong. In the USA the NRC has an similar problem. The US now says that the evacuation zone at Fukushkma should be 50 miles. Meanwhile, NRC planning for similar events in the US sets evacuation zones at 10 miles.
I was contrasting the simplistic name calling of the original post with the current real world crisis. I think the term 'blowhard' was accurate. After reading the responses, I would amend it to 'smug hypocritical blowhard', which is think is more to the point. I hope this clears things up for you.
Re:Never going to happen. (Score:2)
I suggest you go to Google and look up the news for the launch of Cassini.
Hysteria is the correct term.
http://articles.cnn.com/1999-08-16/tech/9908_16_cassini.flyby_1_earth-flyby-saturnbound-probe/2?_s=PM:TECH [cnn.com]
You are disingenuous, a troll, and a blowhard.
--
BMO
Re:Never going to happen. (Score:2)
I grew up a mile from a research reactor (University of Rhode Island Graduate School of Oceanography).
I've been in it.
Now shut up and go away.
--
BMO
Re:Never going to happen. (Score:2)
Yeah, because the difference between the unrealized fear of launching a lump of nuclear material into space is indistinguishable from the real danger of being present during an active nuclear accident.
I especially like the irony of you calling him a blowhard. Well done.
Not clear fusion is the best option (Score:2)
Fusion would provide a higher specific impulse than fission - in theory. Due to the large weight of the laser systems and the fuel tanks though, it isn't clear that in a practical design a fission rocket wouldn't be better
Its pretty easy to imagine a fission rocket that used it's fuel pretty efficiently, then used the waste products as reaction mass in an ion drive. . (you might even be able to use the fuel as a structural material before you burn it)
If you are willing to use a solar system based drive laser you can do even better. A soft X-ray laser (say 1 KeV) only needs a 100nm thick sail but has far fewer diffraction problems than a optical launch laser.
Re:Not clear fusion is the best option (Score:2)
Re:Not clear fusion is the best option (Score:2)
Unless you are planning a to build a LOT of really big star ships, fuel cost isn't likely to be a big issue. Uranium is something like $50/Kg, so 10,000 tons (suitable for a comfortable sized spacecraft is only $50M, pretty insignificant.
Mining uranium at your destination might be a big issue - not clear at that tech level how difficult it would be to mine metallic asteroids for fissionable materials.
--- Joe Frisch
Laser fusion never worked (Score:3)
40 years ago, the idea of triggering fusion with a laser seemed promising. That's what Lawrence Livermore's Nova laser was supposed to be for. But laser ignition didn't work as an energy source. [wikipedia.org]
Maybe someday, but not yet.
Re:Laser fusion never worked (Score:2)
The future may be closer than you think [wikimedia.org]
Re:Laser fusion never worked (Score:2)
It doesn't have to be an energy source for being usefull as a propelent.
NERVA (Score:2)
http://en.wikipedia.org/wiki/NERVA
'NERVA demonstrated that nuclear thermal rocket engines were a feasible and reliable tool for space exploration, and at the end of 1968 SNPO certified that the latest NERVA engine, the NRX/XE, met the requirements for a manned Mars mission. Although NERVA engines were built and tested as much as possible with flight-certified components and the engine was deemed ready for integration into a spacecraft, much of the U.S. space program was cancelled by the Nixon Administration before a manned visit to Mars could take place. NERVA was considered by the AEC, SNPO and NASA to be a highly successful program; it met or exceeded its program goals. Its principal objective was to "establish a technology base for nuclear rocket engine systems to be utilized in the design and development of propulsion systems for space mission application".[1] Virtually all space mission plans that use nuclear thermal rockets use derivative designs from the NERVA NRX or Pewee.'
Since we can't actually build a fusion drive, this seems like a much more promising technology.
Re:NERVA (Score:2)
When this fails (Score:3)
Re:When this fails (Score:2)
And the point is... (Score:2)
So, a really basic animation that practically anyone can do is worthy of a Slashdot story - why?
Re:And the point is... (Score:2)
Right - a 1996 era quality video is news because "nobody has done it yet".
Basic "Twilight Zone" problem. (Score:5, Insightful)
25 years later, they build a ship that can make the journey in 50 years. Off it goes.
74 and a half years later, they build a ship that can make the journey in a day.
Hopefully there's no one in "suspended animation" or "space children" on the first two ships, otherwise they're gonna be pretty pissed off.
This is why getting people to commit to the effort to build an interstellar probe is pretty much a non-starter. We're perfectly happy to wait for the "breakthrough breakthrough" thankyouverymuch.
.
Re:Basic "Twilight Zone" problem. (Score:2)
Because everyone thinks like you. That's why nobody's ever moved off to a frontier, they'd rather wait for the airport to get built and fly there.
Hey, wait a second...
that's ridiculous (Score:2)
no on is waiting because the tech isn't good enough to make it easy. if we had the tech and the economic might to get alpha centauri, even if it took 500 years, we'd have thousands of volunteers to make history like that
Copropulsion (Score:2)
Incorrect terminology (Score:2)
The correct term is defecation.
could we get it working on terra firma first? (Score:2)
priorities people
petroleum funds ultraconservative wahhabi islam, coal gives us air pollution, fission?: fukushima, etc
yes, fusion will have radioactive byproducts too, but not the 10,000 year half life variety (i believe it is a decade or two for the worst... tritium is it?)
and yes i know the other standard answer: we already have fusion power, it's called the sun (solar panels... petroleum and coal even are fusion energy storage vectors, give or take a couple million years)
and please don't give me the boutique sources
we need fusion plants, on terra firma, asap
Anathem spoiler (Score:2)
The "aliens" use a fission-propelled starship; I believe Stephenson got the idea from project Daedalus.
Great read, with the usual Stephenson caveat - you probably won't be happy with the ending.
Project Icarus (Score:2)
Chevron nine... locked.
With luck, it will look like this... (Score:2)
With luck, it will look like one of these designs (with the FTL engines hopefully added on soon after)
Fusion Engines on a starship [startrekphase2media.com]
Re:Fusion powered propulsion exists! (Score:5, Interesting)
Re:Fusion powered propulsion exists! (Score:2)
Yes, because Beryllium is such a nice material to work with.... I hope they stick with mylar.
Re:Sun's gravity well?! (Score:2)
Re:Fusion powered propulsion exists! (Score:2)
So... if we can just circle the sun with superconducting cables and learn how to manipulate the magnetosphere (a trustworthy mutant would come in handy here), could then generate CME's pointed in the right direction to get a solar sail probe on it's way!
Re: Using Fusion To Propel an Interstellar Probe. (Score:3)
Well you just accelerate in the other direction to slow down. It takes almost as long to slow down as it did to get up to speed ('almost' because you are now lighter having lost some mass) so you need to start braking early, and in fact you may well spend half your trip accelerating and the other half decelerating.
And it's not as simple as 'send out probes while you fly past' either, otherwise your probes need to be able to decelerate from whatever speed you are doing down to a slow enough speed to land on / orbit the planet, which isn't easy if you are already going at any decent fraction of C. Using the planets gravity will help to some extent, but I think even that has its limits.
Re: Using Fusion To Propel an Interstellar Probe. (Score:2)
I found this rather smart gentleman's video (however, regarding the fictional propulsion system from the movie Avatar) disproving - scientifically - the possibility of interstellar travel in reasonable time frames.
http://www.youtube.com/watch?v=D6H1TxRGLUc [youtube.com]
Re: Using Fusion To Propel an Interstellar Probe. (Score:3)
I found it a rather tedious video (the narrator could stand to speak at least twice as fast). But the propulsion system is never described in the movie Avatar, so he's just making a lot of assumptions. (I don't believe Alpha Centauri is ever mentioned by name either -- another assumption).
Either way he doesn't disprove anything: he sets up a strawman (his assumptions of how the Avatar starship worked) and knocks them down again. In the context of that strawman, he's right (at least, I assume so -- I skipped over a bunch of that video). But that's not to say there aren't other mechanisms for getting from here to there in reasonable (for some values of reasonable) time frames. Indeed there are, although they may be impractical for engineering or economic reasons, not scientific ones.
Re: Using Fusion To Propel an Interstellar Probe. (Score:2)
Don't get me wrong, there is lots wrong with the Avatar science (walkers? everything man operated? unobtainium that you can't synthesize? ) and even stuff wrong with the antimatter engines. But the basic premise is quite doable, both beam rider and antimatter rockets can get 50% c and better in theory with "practical" construction size and mass ratios. Another 100+ years of engineering, who knows.
Re: Using Fusion To Propel an Interstellar Probe. (Score:3)
Soapbox youtube videos are meant for people with a greater attention span than I have. Let me know when the book version comes out.
Re:Project Icarus?! (Score:2)
No, they plan to use the intergalactic hyperdrive on the Daedalus.
Re:Project Icarus?! (Score:2)
Re:Project Icarus?! (Score:2)
Re:Propellantless electrical propulsion is better (Score:2)
Re:Timing? (Score:2)
We can build lasers that can hit supersonic missiles moving erratically at 10 km from an aircraft, I think hitting a slow moving projectile from less then 100m is the least of this projects worries.
Re:bestdscard (Score:2)
Re:Oh great (Score:2)
The Fission powered Orion was possible with 1960's era tech and would be even easier now. Plus there is no reason to think that we won't eventually acheive useful fusion. For instance, Tri-Alpha is talking about breakeven energy within 2 years...
This tech is really the ONLY interstellar tech that is reasonable with our current understanding.
Re:Oh great (Score:2)
For instance, Tri-Alpha is talking about breakeven energy within 2 years...
Last I heard, that doesn't mean the same think it does to the rest of the world. For them, break even means they measured more energy than they put into the system. That's it. That's an extremely far cry from harvesting the output energy, let alone harvesting in such a manner which is still above breakeven. Even more so, that's a long way toward then redirecting the harvested energy back into a sustainable process. And that completely ignores that their numbers represent a single, completely unsustainable burst of energy. Generally, hours to months are required before the next fusion attempt is possible. That's not even close to any sort of practicality in our lifetime.
Hell, sustainable fusion and making use of zero of its output energy, in of itself, would be an unparalleled human accomplishment that completely ignores something like another dozen feats of equal complexity are required before we can even begin to discuss viable fusion power for humanity.
I used to be completely excited about the potential for fusion power within my lifetime. After all, its always twenty to fifty years out. The reality is, that's complete bullshit. Some time ago I bothered to actually learn something of the associated science. What a complete disappointment and shattering of my nieve ignorance. Frankly, if we have fusion power in less than 150-200 years from now, especially with the borderline funding fiasco (good 'ol boy system) associated with current fusion research, it will be a literal miracle. Personally, I'm betting fusion is another 300-500 years from now, if in fact its even possible at the physical scales they are currently attempting to do so.