Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Using Fusion To Propel an Interstellar Probe

samzenpus posted about 3 years ago | from the nukes-in-space dept.

Sci-Fi 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."

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered


Is the name of the next project... (0)

Anonymous Coward | about 3 years ago | (#35740796)


bestdscard (-1)

bestdscard (2035530) | about 3 years ago | (#35740840)

Our website is making a great promotion now.There are many preferential Acekard 2i [bestdscard.com] on sale, hot saleCheap DSi card [bestdscard.com] such as: Supercard DSTWO [bestdscard.com] ,R4 DS [bestdscard.com] ,M3i Zero [bestdscard.com] ,R4i [bestdscard.com] ,R4i Gold [bestdscard.com] ,superCard DS Onei [bestdscard.com] ,R4DS [bestdscard.com] ,ackeard 2.1 [bestdscard.com] ,DSi card [bestdscard.com] ,M3 DS Real [bestdscard.com] ,R4i SDHC [bestdscard.com] ,DSTT [bestdscard.com] ,DSTTi [bestdscard.com] ,R4i RTS [bestdscard.com] ,R4 [bestdscard.com] ,R4DS [bestdscard.com] ,R4 SDHC [bestdscard.com] ,M3 Real [bestdscard.com] ,AK2 [bestdscard.com] ,AK2i [bestdscard.com] ,Xbox 360 [bestdscard.com] ,M3 Zero [bestdscard.com] ,buy m3i zero [bestdscard.com] ,M3i 0 [bestdscard.com] ,M3iZero [bestdscard.com] ,M3i [bestdscard.com] ,M3 Real i [bestdscard.com] ,M3i Zero Sakura [bestdscard.com] ,Ez flash [bestdscard.com] ,r4ds [bestdscard.com] ,buy r4ds [bestdscard.com] ,r4 card [bestdscard.com] ,r4 for ds [bestdscard.com] ,wholesale r4 cards [bestdscard.com] ,NDS Card [bestdscard.com] ,Nintendo DS Card [bestdscard.com] ,Nintendo DS Supercard [bestdscard.com] ,Nintendo DS Lite [bestdscard.com] ,Nintendo DS Accessories [bestdscard.com] ,Buy R4i SDHC [bestdscard.com] ,supercard dstwo wholesale [bestdscard.com] ,DSi R4i [bestdscard.com] ,R4i Dsi [bestdscard.com] ,Nintendo DSi R4i [bestdscard.com] ,R4 NDS [bestdscard.com] ,4i DSi XL [bestdscard.com] ,R4i Card [bestdscard.com] ,Buy R4i [bestdscard.com] ,buy r4i card [bestdscard.com] ,acekard 2i buy [bestdscard.com] ,buy acekard 2i [bestdscard.com] ,buy acekard2i [bestdscard.com] ,buy acekard [bestdscard.com] ,acekard ii [bestdscard.com] ,Acekard 2i [bestdscard.com] ,acekard2 [bestdscard.com] ,acekards [bestdscard.com] ,acekard [bestdscard.com] ,reader card [bestdscard.com] ,supercard [bestdscard.com] ,supercard dsonei [bestdscard.com] ,supercards [bestdscard.com] ,supercard 2 [bestdscard.com] ,flashcards [bestdscard.com] ,flashcard [bestdscard.com] ,flash card [bestdscard.com] ,where to buy r4i [bestdscard.com] ,where can i buy r4i [bestdscard.com] to get 5% off coupon code “bestdscard [bestdscard.com] ”,Best DSi card [bestdscard.com] Free and Fast shipping for you

Re:bestdscard (1)

FunkyRider (1128099) | about 3 years ago | (#35741066)

Dear sir, I wish you and your entire ecosystem die an agony death.

Re:bestdscard (1)

TheRaven64 (641858) | about 3 years ago | (#35742418)

Why? He's done us a valuable service. I now know that bestsdcard.com is not a company that I'd want to do business with, so they've gained a line in my hosts file to make certain that I never accidentally visit their site. I just bought some SD cards, so I probably won't need to for a little while, and next time I'm looking then I won't need to check the reputation of this site, I just won't see it at all.

Or fission (2, Interesting)

the_humeister (922869) | about 3 years ago | (#35740868)

http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) [slashdot.org] ">Project Orion from the 1950s

Re:Or fission (5, Interesting)

mirix (1649853) | about 3 years ago | (#35741068)

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 (1)

Sir_Lewk (967686) | about 3 years ago | (#35741894)

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 (1)

rbrausse (1319883) | about 3 years ago | (#35742032)

afaik the nearest one is at least 147100000 km away - and not one of these reactors was launched from earth

Re:Or fission (1)

gstoddart (321705) | about 3 years ago | (#35743890)

afaik the nearest one is at least 147100000 km away - and not one of these reactors was launched from earth

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.

Re:Or fission (0)

Anonymous Coward | about 3 years ago | (#35742294)

You do realize that practically all major naval vessels are nuclear powered, right?

Re:Or fission (1)

TheRaven64 (641858) | about 3 years ago | (#35742430)

Interesting fact about ships: they don't have to be able to fly. This means that they can have a huge amount of shielding around the reactor. When they do sink, they tend to go straight down. A reactor leaking a little bit on the bottom of the ocean is a lot less of an environmental problem than a reactor exploding a few miles up and having its fuel scattered over a wide area.

Re:Or fission (1)

gstoddart (321705) | about 3 years ago | (#35743982)

A reactor leaking a little bit on the bottom of the ocean is a lot less of an environmental problem than a reactor exploding a few miles up and having its fuel scattered over a wide area.

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 (1)

AmiMoJo (196126) | about 3 years ago | (#35742488)

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 (1)

hey! (33014) | about 3 years ago | (#35743110)

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 (0)

Anonymous Coward | about 3 years ago | (#35743590)

It's also worth noting that we assigned that role to submarines once they became nuclear powered.

The long mission lengths and relative autonomy are a big plus to a craft that has a refueling cycle measured in years or decades. An aircraft would have a less restricted range of motion that a submersible, but the buoyancy requiernments are more touchy on an aircraft. Until you actually try to build a nuclear air plane and fail there's no reason to think that it's not possible.

Re:Or fission (0)

Anonymous Coward | about 3 years ago | (#35743136)

Those would be an effective weapon for a country with a scorched earth policy. If a bomber is shot down over enemy territory, it still meets its objective.

Re:Or fission (1)

GooberToo (74388) | about 3 years ago | (#35743892)

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 (0)

Anonymous Coward | about 3 years ago | (#35744172)

Apparently Orion IS possible in theory it just has a few bugs to iron out. But one of the reasons it didn't go any further (the primary reason) is the treaty banning nuclear detonations in space. I remember heading that there were some possible issues with radiation that needed to be addressed, having to do with the crew module or something.
Currently today Project Orion would be the ONLY feasible way we could travel to the nearest galaxy within a human lifetime. After all it would be a great way to use up all the nuclear bombs, they would serve a greater purpose rather than simply just destruction and contamination of ground.

RE: Using Fusion To Propel an Interstellar Probe. (1)

bejiitas_wrath (825021) | about 3 years ago | (#35740896)

This sounds like a good way to get somewhere fast, but what about slowing down? The Daedalus probe was to shoot past Barnards star and send out probes to examine the planet, but the actual craft would just keep on going into deep space maybe forever. But if we want to ever see the planets orbiting distant stars then we need to move away from chemical rockets and into more exotic forms of propulsion. Sure we may not have Star Trek Warp Drive, but we can at least send the V,Ger [memory-alpha.org] probe into space and make our mark on the universe. Maybe we could catch up with the Voyager probe and bring it back to Earth.

Re: Using Fusion To Propel an Interstellar Probe. (1)

Anonymous Coward | about 3 years ago | (#35740982)

Simple - you turn the craft around and use the same propulsion mechanism to decelerate.

Re: Using Fusion To Propel an Interstellar Probe. (2)

jamesh (87723) | about 3 years ago | (#35741060)

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. (1)

MacGyver2210 (1053110) | about 3 years ago | (#35741172)

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. (2)

AJWM (19027) | about 3 years ago | (#35741334)

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. (2)

jamesh (87723) | about 3 years ago | (#35741788)

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: Using Fusion To Propel an Interstellar Probe. (1)

Anonymous Coward | about 3 years ago | (#35741210)

Eh? This is a more exotic form of propulsion -- afraid I don't see your point there.

And it's perfectly suited to slowing down -- the reason the mission profile was a fast flyby is because no matter what drive tech you dream up, decelerating your vehicle takes exactly the same amount of fuel as accelerating, which means not double the fuel, but even more to accelerate the vehicle + the deceleration fuel, to say nothing of the necessarily more massive vehicle to hold the more fuel. Until you can get fuel down to a mass fraction less than, say, 50%, that's simply ridiculous. It also increases transit time.

Example math at 75% mass fraction: (Note that I'm unaware of any concept approaching this for interstellar (5-10 ly) travel on the order of human lifespan -- from Wikipedia, Daedalus would be 92% for a 50-year flight, Orion would be 75% for a ~200-year interstellar flight.) And all simplifying assumptions here are conservative -- you'll actually increase fuel and mass more than this...

  • 1 unit vehicle, accelerates to $SPEED in with 3 units fuel.
  • To come to a stop then, need 1 unit vehicle + 3 units fuel = 4 units dead weight.
  • So we need 12 units more fuel for acceleration, now we have 5x the fuel mass, and 4x the total mass at launch.

Hope your design allows assembly and/or fueling on orbit, else you get to develop a new heavy lift rocket for that. :)

Now at least for daedalus, I'm pretty sure R&D (fixed cost) and fuel costs were the majority, making it cheaper to launch, say, 10 flyby missions than 1 stopping mission. In that case, wouldn't it be hella illogical to send stopping missions to a spot we're not even sure has interesting planets, rather than exploring 10 candidate systems, and eventually sending a second (or later) generation mission (with greatly reduced chance of failure, and somewhat improved efficiency) to the interesting ones?

Really, I've done the math, and even a Heinlein torch (i.e. direct mass-to-energy conversion) requires huge mass fractions of fuel. (Of course, say what you may about his politics ;), but Heinlein's science was usually pretty much right, and this was no exception -- just had to run the numbers to satisfy myself. Read Time for the Stars -- as far as I'm concerned, one of his best juveniles -- if you haven't...) It sounds like you're seriously considering Star Trek drive tech as a mild case of optimism, but it's really pure bullshit, and there's not a damn thing in physics to make one suppose that we'll ever get anything like that.

Re: Using Fusion To Propel an Interstellar Probe. (1)

Jessified (1150003) | about 3 years ago | (#35741478)

If you do a fly by, doesn't that give you only a matter of hours to pass through the solar system and do what you want? If light take 8 minutes to reach the Earth, and this is about 0.12c, then presumably a 50 year trip becomes less than a day of visiting time?

Granted, research is being conducted before entering the solar system and presumably in the years after passing through. But in principle, it seems so fleeting.

Re: Using Fusion To Propel an Interstellar Probe. (1)

Anonymous Coward | about 3 years ago | (#35741578)

Yeah, you'd spend only a day within 1 AU of your target, x however many probes you deploy to pass through on more-or-less parallel trajectories (18 for Daedalus). But remember Earth's orbit is a tiny bit in the middle of the solar system, and you'd have a month or more of observations equivalent to sitting in Earth orbit watching $OUTER_PLANET or better. It'd be an insanely huge advancement of current knowledge of other systems -- not as big as entering an orbit and watching for years, to be sure, but I think the advantage it gives your future missions would be well worth the 50-year delay -- I'm not suggesting we give up on that at all, just that stopping is so expensive we need to make the most of that investment with a sortie or two of flyby missions.

Project Daedalus, FWIW, would have had 20m telescopes on it for the observations while approaching and leaving, so you'd be getting damned good observations from lightyears away. And slingshotting the main space craft around the target star for a flyby of another nearby star (for more results perhaps 100 years along) is a real possibility, though AFAIK it wasn't really in the Daedalus profile.

The strategy of doing flybys before orbiters before landings is exactly what we've done in most of our own solar system -- and while I don't have data to back me up, I'd say the results we've gotten from orbiters wouldn't be near as good if we hadn't had the flybys to know what's worth looking at, and therefore what sort of science package we should fly.

Fusion powered propulsion exists! (0)

Anonymous Coward | about 3 years ago | (#35740898)

Why is this such a big deal? They have been thinking of using solar sails (sun is big fusion reactor) for decades...

Re:Fusion powered propulsion exists! (4, Interesting)

khallow (566160) | about 3 years ago | (#35740964)

And theoretically, you can get to 0.01c [nasaspaceflight.com] with solar sails. The original calculation is a bit screwy since it assumes a solar sail with mass including payload of 1 kg per square kilometer. But it ignores the effects of the Sun's gravity well. Acceleration deep in a gravity well and for which the vehicle escapes the gravity well results in more delta v than acceleration outside of a gravity well. This is called the Oberth effect [wikipedia.org] . Further on down, someone cites a researcher who supposedly came up with a beryllium sail that could achieve 0.03c.

Re:Fusion powered propulsion exists! (1)

toQDuj (806112) | about 3 years ago | (#35742008)

Yes, because Beryllium is such a nice material to work with.... I hope they stick with mylar.

Sun's gravity well?! (1)

Arrepiadd (688829) | about 3 years ago | (#35742348)

For the record, you are suggesting we put a ship close enough to the Sun to use its gravity well to catapult us out? I mean, how close do you suggest? Do you like it rare, well done or charcoally?

Re:Sun's gravity well?! (1)

khallow (566160) | about 3 years ago | (#35743776)

Close enough that it barely functions as a solar sail. If we had some magic substance which allowed us to graze the photosphere (or however close you can get and still maintain orbit for a time), then that probably would be the limit.

Physics our Enemy (1)

Bruha (412869) | about 3 years ago | (#35740906)

Unless we figure out something that allows us to beat light speed even the nearest star is 4 years + away.

Re:Physics our Enemy (2)

Penguinisto (415985) | about 3 years ago | (#35740946)

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 (1)

mysidia (191772) | about 3 years ago | (#35741050)

Unless we figure out something that allows us to beat light speed even the nearest star is 4 years + away.

You know what they say... "If you can't beat them, join them"

There may be a closer star that has formed that you cannot see from earth right now, because its light has not yet reached earth <EG>

Re:Physics our Enemy (2)

MadnessASAP (1052274) | about 3 years ago | (#35741664)

Unlikely, clouds of interstellar dust several light years across tend to get noticed, especially if they're that close.

Re:Physics our Enemy (0)

Anonymous Coward | about 3 years ago | (#35741720)

So you think that a new star may have formed within four lightyears of earth less than four years ago (if it were longer ago, we'd be able to see it, obviously)? Would you like to take a bet on that? We'll have the answer in less than four years.

Re:Physics our Enemy (0)

Anonymous Coward | about 3 years ago | (#35741362)

It's not gonna happen. If it were possible to exceed lightspeed, we'd be fending off annoying tourists from the future by now.

This doesn't rule out all cool sci-fi futures, though. Alien and Avatar were both FTL-free, to name just two.

Maybe we are the first... (1)

clonan (64380) | about 3 years ago | (#35744050)

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:Physics our Enemy (1)

Jamu (852752) | about 3 years ago | (#35742458)

If we beat light speed, I think we'll be having too much "fun" travelling backwards in time.

Don't bother, they won't listen (1)

elrous0 (869638) | about 3 years ago | (#35743818)

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.

Dupe (0)

Anonymous Coward | about 3 years ago | (#35740916)

From months ago, years ago, etc - why do these d-bags keep getting publications?

Timing? (0)

Anonymous Coward | about 3 years ago | (#35740926)

It appeared as though the lasers were all on the same plane, firing at an object moving perpendicular to that plane, right at the point where it passes through that plane. Wouldn't it be incredibly hard to make this work? Why not have the laser hitting it at all sorts of different symmetrical angles? And what powers the lasers?

Re:Timing? (1)

MadnessASAP (1052274) | about 3 years ago | (#35741680)

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.

Why Icarus? (4, Insightful)

chihowa (366380) | about 3 years ago | (#35740944)

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? (2)

TheRaven64 (641858) | about 3 years ago | (#35742442)

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? (1)

drinkypoo (153816) | about 3 years ago | (#35742844)

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.

Project Icarus?! (1)

balajeerc (1461659) | about 3 years ago | (#35740958)

Don't they have them interstellar gates that they can just jump through? Ask their scientists to the famous Dr.Nicholas Rush.

Oh great (0)

Anonymous Coward | about 3 years ago | (#35741028)

More speculations, delusions and fantasies based on barely theoretical possibilities for which we will never, ever have the energy or technology to accomplish. Summon the Space Nutters to drool and froth at the artist's conceptions and animations!

Re:Oh great (1)

clonan (64380) | about 3 years ago | (#35743876)

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 (1)

GooberToo (74388) | about 3 years ago | (#35744336)

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.

Never going to happen. (3, Insightful)

bmo (77928) | about 3 years ago | (#35741048)

"Nukular" hysteria will kill it.

Remember when we launched Cassini with a radioisotope thermo-electric generator?


Every time I see shit like that, I want to slap people.


Re:Never going to happen. (0, Troll)

Required Snark (1702878) | about 3 years ago | (#35741576)

Move to Fukushima. Now. Since you seem to believe that any fear of radiation is, to use your phrase, "Nukular" hysteria.

Put your money where your mouth is. You could buy a place really cheep, because a lot of people are going to be moving out.

Or just go for a visit. I suggest you camp outside, as close to the 20 km nuclear plant exclusion zone as you can get. Take a swim in the ocean. Spend a lot of time outdoors. Drink water from streams or rain water. Eat local produce and fish. Since they can't sell this stuff, they might give it to you for free.

You could also relocate to Chernobyl. There are a few hundred stubborn/stupid people who are staying there. I think you would fit right in.

Post a reply that you want to go and I'll start raising funds for you trip. I would guess that a lot of people would pitch in a few bucks. It would be an inexpensive way for the rest of us to have some fun. If you don't accept the offer, you are a blowhard and hypocrite. If you do go you will increase your chances of dying, and the average intelligence of the human race will increase. It's a win/win.

Re:Never going to happen. (0)

Anonymous Coward | about 3 years ago | (#35741768)

I would happily move within the 20lm zone of Fukushima to prove the point. However, Chernobyl is a different story as that was a proper nuclear disaster.

Re:Never going to happen. (3, Insightful)

Nutria (679911) | about 3 years ago | (#35741800)

any fear of radiation is, to use your phrase, "Nukular" hysteria.

Good job there of putting words in his mouth.

ich bin space nutter (1)

Thud457 (234763) | about 3 years ago | (#35744410)

Good, maybe we can get the antinuclear hysterics on one side and the space nutters on the other. That would be an amusing scuffle!

Re:Never going to happen. (3, Insightful)

LBU.Zorro (585180) | about 3 years ago | (#35742624)

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


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 point, or you were stupid enough to smoke. You can only give a statistical association between the radiation leaks and increased cancer rates at much higher levels of radiation and greater exposure - unlike things like car crashes were you can say they died from a car crash, what cause the cancer that kills someone you can't say for certain unless they have a statistically significant exposure to radiation - and even then you can only assign part of the blame to the radiation.

If you really are that petrified about radiation and the possible implications for you in the future I suggest never getting out of bed, cause it's risky out there doing absolutely anything.


Re:Never going to happen. (1)

bmo (77928) | about 3 years ago | (#35742998)

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.


And by the way, I would be more afraid of parasites drinking from any random stream than radionuclides.


Re:Never going to happen. (1)

LBU.Zorro (585180) | about 3 years ago | (#35744152)

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....


Re:Never going to happen. (1)

bmo (77928) | about 3 years ago | (#35742878)

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.


Re:Never going to happen. (1)

MachineShedFred (621896) | about 3 years ago | (#35743598)

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 (1)

joe_frisch (1366229) | about 3 years ago | (#35741166)

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.

Parabola, not semi-sphere (0)

Anonymous Coward | about 3 years ago | (#35741180)

...that's my main concern with the project icarus depiction. Horrible mirror shape.

Propellantless electrical propulsion is better (0)

Anonymous Coward | about 3 years ago | (#35741184)

We may as well go back to the engine as well. Why use fusion propulsion when we have propellantless electrical propulsion eg emdrive .

Re:Propellantless electrical propulsion is better (1)

wagnerrp (1305589) | about 3 years ago | (#35741504)

Because there is no such thing as a propellantless propulsion system? The closest you could get would be light, and the thrust you get some shining a laser out the back is negligible. All of our current 'electric drives' function by ionizing a light inert gas, or heating it to a plasma, before propelling it out the back using an electromagnetic or electrostatic field.

Re:Propellantless electrical propulsion is better (0)

Anonymous Coward | about 3 years ago | (#35741686)

Yeah, why use a propulsion method which actually works in accordance with known laws of physics, when we have one man proclaiming he's discovered a violation of conservation of momentum, no reproduction of his results by others, and no proposed new physics to explain it? Drop everything and get on that!

uniquegucci (-1, Offtopic)

tonnyben (2022156) | about 3 years ago | (#35741270)

[url=http://www.uniquegucci.com]gucci clutches[/url] [url=http://www.uniquegucci.com]gucci totes[/url] [url=http://www.uniquegucci.com]gucci handbags[/url] [url=http://www.uniquegucci.com]gucci shoulder bags[/url] gucci clutches [uniquegucci.com] , gucci totes [uniquegucci.com] , gucci handbags [uniquegucci.com] , gucci shoulder bags [uniquegucci.com] , gucci clutches [uniquegucci.com] gucci totes [uniquegucci.com] gucci handbags [uniquegucci.com] gucci shoulder bags [uniquegucci.com] gucci clutches [uniquegucci.com] gucci totes [uniquegucci.com] gucci shoulder bags [uniquegucci.com] gucci messenger bags [uniquegucci.com] gucci wallets [uniquegucci.com] gucci backpacks [uniquegucci.com] http://www.uniquegucci.com/ [uniquegucci.com] Our email:uniquegucci@live.com

test (-1)

Anonymous Coward | about 3 years ago | (#35741350)

sadf asdf dsaf sds fdasf

What's to see here? (1)

NortySpock (1966236) | about 3 years ago | (#35741410)

"Lookee! We made a shiny trailer of something that would be really cool!"

Sure, it looks cool, but is that the only thing you've produced?


godel_56 (1287256) | about 3 years ago | (#35741422)


'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 (1)

TheDarkMaster (1292526) | about 3 years ago | (#35743048)

Is a better idea. For the idea using lasers, you need power to the lasers, and I think (ok, ok, i'm not a enginner) a constant impulse is better than one pulsed because the possible vibration (and failure modes, what happens if the pellet gets stuck?).

Better Alternative Pulsed Fusion Scheme (0)

Anonymous Coward | about 3 years ago | (#35741752)

Friedwardt Winterberg proposed a more robust and less exacting system that uses the entire spacecraft as a capacitor to fire a hugely powerful ion beam at the fusion target, and allowing the use of more commonly available fuel (deuterium only, no tritium or helium 3).


using confusion to propel us into world war (0)

Anonymous Coward | about 3 years ago | (#35742834)

seems as though we could do better. definitely could resolve our energy 'issues', if we weren't kept in the dark by our fearful rulers, with their .5billion remaining pop. fake us out agendas? maybe not. pity.


Basic "Twilight Zone" problem. (4, Insightful)

RevWaldo (1186281) | about 3 years ago | (#35743064)

They build a ship that can reach the nearest star in 100 years. Off it goes.

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. (1)

Dr. Manhattan (29720) | about 3 years ago | (#35743400)

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.

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...

Re:Basic "Twilight Zone" problem. (0)

Anonymous Coward | about 3 years ago | (#35743430)

Well here's the thing to do. If you are building a ship for long missions, incorporate a system to let other ships dock with it. Therefore, any faster ships which are developed can collect colleagues in older ships.

Re:Basic "Twilight Zone" problem. (0)

Anonymous Coward | about 3 years ago | (#35743798)

Who's the 'we' in that sentence? I'll take the first trip even if its only significance is that it leads to the second.

that's ridiculous (1)

circletimessquare (444983) | about 3 years ago | (#35744084)

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

could we get it working on terra firma first? (1)

circletimessquare (444983) | about 3 years ago | (#35743854)

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

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account