But it takes 2!
"... obsolete as the stream engine for earth-bound transportation"
Yes, but you are forgetting the power of crossing the streams!
Ghost Busters! Ta da da daaaa!
NASA, and plenty of private individuals, want to put mankind on Mars. Now a team at the University of Washington, with funding from the space agency, is about to start building a fusion engine that could get humans there in just 30 days and make other forms of space travel obsolete. FDR Fusion drive Rocket fuel is just so …
Astonishing, and a great time saver. Since it is claimed to be scalable, imagine what it might do for other mission types.
Imagine it as a way to grab a sled of exotic asteroid belt minerals, etc, and slingshotting them to earth. The rv could be designed to survive by shielding and parachutes. The engine part could be set up to enter a semi orbit and then shove the rv into a proper descent, and the engin returns to the asteroid belt. If profits and mining are successful and steady, a chain of automated sleds and engines could be synchronized.
We might become a rep-Warp civilization in under 200 years, maybe even 100...
This and other reporting leaves a bit unclear if they have actually managed to magnetically crunch even a single pellet so that it produces fusion energy. Until they do, it is just vaporware.
In fact, making the FDR work as explained would mean they have also cracked the problem of making Earth-bound fusion power plants. Write off ITER...
Sorry, but this smells of too-good-to-be-true.
(I also wonder why they plan to use solar panels. Wouldn't it make more sense to divert some of the energy from the explosions for running the machinery?)
Sorry, but you confuse fusion energy generation with propulsion, which doesn't necessarily need to generate anything more than kinetic impulse to the craft.
As the system would be using solar energy to create the magnetic fields and accelerate the fuel pellet, no excess energy is necessary to be released from the engine itself. Hence, without even break-even required for electrical energy generation, the unit would be ineffective for electrical energy generation, but highly efficient at delivering impulses to the spacecraft.
Though, if there were a CERNesque magnetic coil failure at mid trip, the trip would be rather one way and probably not be survivable.
OK, I see what you mean. Still, there are lots of hurdles. The system for feeding the metal liners into the engine is probably quite complex mechanically, more so than just injecting fluids like in traditional rockets or even ion engines. Probably the worst nightmare for the crew would be to find the mechanism has frozen in place after it has been inactive for days during the coasting phase, and the bracing burn needs to be made.
Of course there are hurdles, that is why research is needed (hence the phrase "if we knew what we were doing it would not be research" ;-) ). There are many ways this can go pear-shaped, but I applaud the aim, and the proposal is plausible enough to investigate further. It is an audacious and exciting proposal.
This scheme will need a rethink when going to the outer planets such as Jupiter, or its moon Europa, given the much lower intensity of solar radiation. Some other source of electric power will be needed.
"[more complicated] than just injecting fluids like in traditional rockets..."
That turns out to be a damn sight more complicated that just about anyone believes. In most cases a small internal rocket is used to drive the turbines that drive the pumps in order to get the incredible volume flow needed.
This is why multi-engined rockets sometimes fall over instead of soaring majestically skyward, or change their mind and decide to make for the center of the earth instead of LEO. It is ever so easy for something to go wrong and shut an engine down (or quite often just remove it from the universe in a bloody great fireball).
Science and engineering are hard at the sharp end of spaceflight. One should revere those who get it right as much as one reviles those who get it wrong.
Yes, vaporware for now, I'll be interested to see how they do, how much progress they might make with this.
Failure not to be reviled; failure at the very least hints at what to do right. Worst case, as with Edison and his quest for a filament for light bulb, plod along by eliminating all the stuff that doesn't work. Best case, the light bulb goes on, Eureka!, build it right the next time. Wash, rinse, repeat. It's how it's done. Nowadays we can do more things with computer-aided simulations, but it still comes down to bending metal and throwing a switch.
Interesting re shock absorbers. Sounds worth a try.
For getting some electricity back, exterior line the exhaust cone with coil - magnetohydrodynamics or somesuch, no?
Initial juice for outer Solar system and backup and other stuff, just use a standard fission reactor, but do keep the solar panels. Biggest initial penalty is getting the heavy parts off planet; the rest is far lighter re-supply. And if water from asteroids and Moon becomes available, even better.
Um, no. What I just read about was not a system using solar energy to create the magnetic fields and accelerate the fuel pellet, but a system using solar energy to create magnetic fields that will initiate fusion in a fuel pellet resulting in ejection of highly accelerated particles (without that it would be a plain old boring weakling of an ion engine). And that question remains unanswered. HAS THERE BEEN any single "pellet" compressed all the way to fusion yet in practice? Yes or no?
HAS THERE BEEN any single "pellet" compressed all the way to fusion yet in practice? Yes or no?
No. It's just a proposal to generate $1B in funding. Here's a 30-page pdf which expands on the summary in the Reg link:
http://www.nasa.gov/pdf/716077main_Slough_2011_PhI_Fusion_Rocket.pdf
In short, fusion gain is required to get the necessary energy. The authors discuss Inertial Confinement Fusion (ICF), saying:
"This Inertial Confinement Fusion (ICF) approach has been actively pursued by the National Nuclear Security Administration (NNSA) of the DOE for decades as it represents essentially a nano-scale version of a fusion explosive device.... It appears that the most promising solution to accomplish this is with a large array of high power pulsed lasers focused down on to the D-T pellet....The National Ignition Facility (NIF) at Livermore National Laboratory is now in the process of testing a laser driven pellet implosion capable producing significant fusion gain for the first time....While the expected energy yield is in the range appropriate for propulsion (E ~ 20- 100 MJ), the scale and mass of the driver (lasers and power supplies) is not, as it requires an aerial photograph to image the full system."
Hence the cunning plan to use Magneto Inertial Fusion (MIF), where there's some theoretical work to show "that if the imploding shell on to the magnetized target were fully three dimensional, fusion gain could be achieved on a small scale with sub-megajoule liner (shell) kinetic energy. "
The authors say there are a number of challenges still to be resolved, but "The key to answering all four “hows” stems from current research being done at MSNW on the magnetically driven 3D implosion of metal foils on to an FRC target for obtaining fusion conditions."
So, Vaporware.
I went and printed the PDF link you sent (nothing beats dead trees for reading while in commuter train). Halfway throught it, but it certainly answers most questions people have been later posting to this thread. People, read that PDF before posting nonsense! (I wish I had done so myself).
As you note, the key to the cunning plan is to use a strong magnetic field to make fusion easier. This immediately made me wonder if there were then some less Rube Goldbergian ways to compress the plasma than imploding lithium hoops, which must be a nightmare to manage on a spaceship engine. How about the scheme known to be used in fission bombs: Implode a metal shell with a chemical explosive. This has the advantage that it is known and well-tested technology.
"This has the advantage that it is known and well-tested technology."
It has the disadvantage that it is horribly inefficient, requires precision manufacturing of the implosion shell and explosive coating and precision positioning (and activation) of the detonators or nothing happens.
What you are describing is "Orion".
This question also occurred to me, so I went to the project's website and it repeated the misleading sentence,
"Nuclear fusion occurs when this plasma is compressed to high pressure with a magnetic field. The team has successfully tested this technique in the lab."
On reading it further it becomes clear that in their experiments NO FUSION HAS ACTUALLY TAKEN PLACE.
Yes it seems like a promising project, and it's exciting that it is getting funding, but if they can generate fusion in this way in any reasonable timescale, it will be Nobel Prizes and a place in the history books for them. A whiff of "too good to be true" indeed.
>Sorry, but you confuse fusion energy generation with propulsion...
Propulsion and energy generation are not unconnected, consider the rotor in an alternator, if you make it go round you can make leccy from it.
>...the unit would be ineffective for electrical energy generation, but highly
>efficient at delivering impulses to the spacecraft.
It's putting out more than 200KW though otherwise where has the energy from the fusion reaction gone?
"Sorry, but you confuse fusion energy generation with propulsion, which doesn't necessarily need to generate anything more than kinetic impulse to the craft."
Given that the vast bulk of our electricity generation is based on chemical - kinetic - electromagnetic conversions, why can't this be used (in much modified form) for electricity generation?
You give me some form of controllable kinetic energy, and I'll give you some electricity.
Have a re-read of the article. In the theoretical space vehicle the electricity is being generated by solar cells, this electricity is then used to power the fusion drive and generate impulse thrust. The theoretical concept is converting solar power into a significant amount of thrust.
So yes of course we can use the same mechanism for electricity generation - I see them popping up on roofs all the time these days.
"Have a re-read of the article.....So yes of course we can use the same mechanism for electricity generation - I see them popping up on roofs all the time these days"
Err, you have a re-read of my post and Zanzibar Rastopolous' posts. We're fully aware that in the article electricity is being generated by solar power, and we don't give a stuff. Our identical point was that if you can convert nuclear fusion energy to kinetic energy, Einsteinian intellectuals that we are, we would have thought it relatively simple to convert kinetic energy to electrical energy, like we do for the vast majority of electrical energy on earth.
"Einsteinian intellectuals that we are, we would have thought it relatively simple to convert kinetic energy to electrical energy, like we do for the vast majority of electrical energy on earth."
Not much point in doing that if you are using Electrical energy to generate the Kinetic energy in the first place. Or did you actually think that they are likely to be generating MORE Kinetic energy than the Electrical energy they put in? That has been the unrealised dream of Fusion power research for a long time and we're still 50 years away from being able to achieve it.
Yes, this would produce more kinetic energy than the electricity put in, when in use. Whether there's a net energy gain I don't know - you have to consider the energy cost of manufacturing the fuel pellets, and of boosting them out of the atmosphere so that you can use them without all those pesky NIMBYs getting cross about the thermonuclear explosions.
You give me some form of controllable kinetic energy, and I'll give you some electricity.
Yup, the only problem you need to crack is what to do with those fast moving highly radioactive pellets that you're creating. Not such a problem in space, where everything is bathed in solar radiation anyway, and you're essentially throwing them out behind you.
Agreed. That pretty much rules out taking off from Earth or landing back here.
Doing it do remove a lot of speed prior to re-entry might be OK if you can watch where you point your exhaust.
Possibly not even a good idea for landing on Mars but might be OK for the moon and asteroids.
A deflection field failure could occur for several reason e.g. particle impact in the wrong place, and unless detectable, boom, or at the very least lots _more_ Neutron radiation exposure; yes Fusion gives off lots of Neutrons, so there had better be enough Neutron shielding between the engine, and the engine controller and payload! Oh, BTW, the Neutron shielding will eventually become Radioactive and transmuted, so better be easily replaced if reuse is a consideration.
All this supposes a reliable and affordable system can be produced; if so, maybe we could produce a Fusion version of an internal combustion engine for power generation; yes it's rather low tech, but may work.
>>>That's probably not an insurmountable issue... shock absorbers.<<<
Project Orion was extensively researched and is not entirely dissimilar in principle, in that you're using a series of nuclear explosions to power your craft.
They had a big blast shield and shock absorber arrangement, with 1 atom bomb per half second being chucked out the back. So the shock absorber approach doesn't seem infeasible. Getting meaningful fusion is the deal maker/breaker.
http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29