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Photonic Laser Thruster Promises Earth to Mars in a Week
serutan writes "Using lasers to drive spaceships has been a subject of interest for many years, but making a photonic engine powerful enough for practical use has been elusive. Dr. Young Bae, a California physicist, has built a demonstration photonic laser thruster that produces enough thrust to micro-maneuver a satellite. This would be useful in high-precision formation flying, such as using a fleet of satellites to form a space telescope with a large virtual aperture. Scaled up, a similar engine could speed a spacecraft to Mars in less than a week."
...we fried it duing liftoff.
What sort of acceleration would that be? Would it be multi G-force worth, that might be impractical for humans.
“Common sense is not so common.” — Voltaire
Are we talking about "accidentally cut Venus in half" scaled up? Typically the downside of photonic thrust has been the low power to weight ratio, so for a laser powerful enough to propel a ship to Mars (don't forget that it has to both accelerate and decelerate) that fast I have to wonder just how powerful the laser has to be.
I read the internet for the articles.
And if scaled up, cockroaches run at 800mph and fleas could jump over a mile. However, the increase in mass and energy requirements would make it impossible.
Small scale thrusters using only lasers is a good start, but we'll have to see what else gets bigger with scale, other than just the thrust.
At least now we'll have a way to beat the Kzinti when we make first contact.
I used to carry a bottle of whiskey for snake bite. And two snakes. -Nefarious Wheel
And in response to those two words, I have these eight: "a whole friggin' lot easier said than done".
<sarcasm>Yup... it's just a matter of scale. </sarcasm>
File under 'M' for 'Manic ranting'
Wasn't the Photonic Thruster invented by Gene Roddenberry?
The game.
Anyone know why they keep trying to make extremely super low energy particles and modes of movement into rocket thrusters? If you turn on a flashlight or laser pointer, do you go flying backwards from the kick back? How about if you light off a flashlight sized model rocket motor while holding it? I mean seriously, if they'd been focusing on technologies that are traditionally used to create thrust instead of seeing how they can trick the weakest possible thrust methods into working as an engine, I'd be posting this FROM MARS! This is almost as bad as that giant million mile wide solar sail thing that was supposed to capture the forward energy from particles that barely qualifiy as mass. Oh here's an idea, why don't they take a billion of those little handheld electric fans and try and thrust it out of our atmosphere with that. One of them creates more thrust in an atmoshpere than the equal volume of photon's for God's sake.
Google's Super Secret Search Algorithm: SELECT @search_results FROM internet WHERE @search_results = 'good'
Even ignoring the use for robot probes, extended manned missions will still need supply drops.
Muuuuch better than using those LASERS without Photons.
[I hear that adding the photons also makes them lighter...]
It must have been something you assimilated. . . .
Hell, with that kind of ISP, why even explore Mars, when we can INVADE IT!
This is my sig.
Why is he getting a patent ... for something the government funded!
This is my sig.
Where is the energy coming from to create those photons?
Since you're dealing with a photon drive, the reaction mass usage (as determined by the classic rocket equation) is going to be negligible for the speeds required for interplanetary travel.
In fact, I'm not sure what the reaction mass would be in this case.
But in any case, you're going to need a lot of energy to create that photon thrust. Great phrigging big reactors, which means great, great, phrigging big radiators since you don't have the luxury of a river to carry away your waste heat.
Antimatter might be a compact way to store the required energy, but converting the gamma rays from matter/antimatter reactions to electricity is going to require heat exchangers and great big radiators as well.
Well, anyway, scaling this up is going to involve several bears of a problem.
Also, please note that this "article" is a press release from the guy who made the invention.
But they hafta promise me a headrest on the seat-back.
I did NOT ork that cow!
But-she gives great binary cheese!
.... on a motherfucking Photonic Laser Thruster. I'm not reading the article and I don't give a shit who wants to thrust what where but that wins my award for the best name ever in the history of technology that might facilitate STL interplanetary travel. Snakes. Fuck yeah.
Now wash your hands.
This chap has been around for some time; no one takes his drive
seriously for good reason. Guess he's putting out his own press
releases.
To send a ship to Mars in a week, Thrust should be roughly 10m/s^2 times the ship's weight, which we'll say is only ten metric tons. (Because we're getting there in a week, we can pack light... pack light, get it? I slay me.) That gives us 10^5 Newtons of thrust.
Exhaust Velocity is the speed of light, or about 3*10^8 m/s.
So our power consumption is 3*10^13 Watts.
By comparison, the USA is currently consuming less than 1*10^13 Watts on average.
In other words, if think you think it costs too much to refuel an RV now...
It's not completely implausible to use light to propel a spacecraft, but either that propulsion will be ridiculously slow (e.g. solar sails, laser sails, or the "precisely tweak your satellite's orbit a tiny bit" applications mentioned in the article), or it's going to require ridiculous "cheap antimatter" amounts of energy.
I don't want to be skeptical, but...:
Scaled up, a similar engine could speed a spacecraft to Mars in less than a week.
Right, just like a scaled up ant could carry a house. In movies.
But as any junior engineer knows, you can't just scale things up linearly and expect linearly scaled integrity and results.
In other words, there are solar powered toy cars out there. But math and physics prevent us from simply "scaling" this up to drive actual cars with linearly scaled up speeds.
Meanwhile, it's old-fashioned ion engines for an asteroid mission scheduled for launch later this month, Dawn, which NASA has now taken to calling "The Prius of Space."
Saddle up: Riding with Robots
I wonder why we don't just scale up a bridge right to Mars and drive to there with a drag racer car. If the latter is too slow, I suppose no problem, we can scale it up as necessary.
Assuming you had another one on Mars to slow the thing down!
Let's assume they mean Earth to Mars in a week at their closest to each other (approx. 50 million kms). That's an average speed of approx. 300,000 km/h, or 80 km/s. Presumably the speed at the mid-point would be even higher. So anyone riding the spacecraft better hope that there isn't a malfunction of the "slowing down" laser at the other end, as depending on the angle, that might be enough to exit the solar system altogether!
Well, great to see that PR Newswire has branched out. They're not just about scientology scams and scientology front group scams, anymore.
So the Martian alien invasion IS imminent.
The article says he achieved thrust of 35 uN. 35 micro Newtons? That's a lot of "up" to scale into.
Program Intellivision!
To get to Mars in a week, only about 5m/s^2 is necessary. ( Mars at 1G is about 3.5 days, so a week is 1/2 G, turnaround halfway )
So call it a mere 1.5*10^13 watts.
Damn. I read the title as
"Pontiac Laser Thruster Promises Earth to Mars in a Week"
I think I need to get help.
...how the momentum is somehow created. Doesn't the sunlight absorbed during power generation cancel the laser output?
Tsunami -- You can't bring a good wave down!
Senior Aerospace Engineer at AFRL, Dr. Franklin Mead, "Dr. Bae's PLT demonstration and measurement of photon thrust (is) pretty incredible. I don't think anyone has done this before. It has generated a lot of interest."
Perhaps the demonstration would generate even more interest if it were credible.
A harsh lesson that I have learned here...
If you're going to make a lame joke, at least include a cite so there's a chance of getting modded up as "informative."
The Mars Climate Orbiter:
http://en.wikipedia.org/wiki/Mars_Climate_Orbiter
"The Mars Climate Orbiter was intended to enter orbit at an altitude of 140-150 km above Mars. However, a navigation error caused the spacecraft to reach as low as 57 km. The spacecraft was destroyed by atmospheric stresses and friction at this low altitude. The navigation error arose because a NASA subcontractor (Lockheed Martin) used Imperial units (pound-seconds) instead of the metric units (newton-seconds) as specified by NASA."
"In contrast, Bae's patent-pending PLT breakthrough places the laser medium within a resonant optical cavity between two platforms to produce a very stable and reliable thrust that is unaffected by mirror movement and vibration -- ideal for spacecraft control or propulsion."
Ummm... yeah the laser gain medium is ALWAYS inside a resonant optical cavity. That's what makes it a fricken LASER.
Whatever "between two platforms" means is completely unexplained.
The problem with all of this is scale, right? The energy required to send larger and larger objects would be impractical.
So, what's the smallest thing we can send, then? How small can we make a satellite that can send some information back?
It may not be useful for transporting people to the other end of the universe in a practical amount of time, but I'm sure sending a probe that can check up on Mars every week or so would be of some sort of slight interest to researchers...
Of course, there's the issue of the touchdown...
Hooray! They've finally discovered how to make an Impulse Drive engine. Now all they have to do is tie in a fusion reactor and voila! sublight speed! I'm just kidding. I didn't RTFA.
I took a space tech studies class eons ago at Rensselaer Polytechnic Institute from a guy named Leik Myrabo. He was working on a terrestrial laser powered spacecraft (I think his book was named The Future of Flight. Basically, you fire a laser at a mirrored ship that reflects the beam and heats air to produce thrust. When I took the class he wanted the lasers to be mounted on satellites, then he started working with ground-based designs. I looked up his research a while back and wasn't able to find anything new (I'm guessing the research hit a wall). There's a video of a small demo model being shot up, but I'm too lazy to track it down again.
The really interesting thing about his class though was that the previous summer he was out in the desert somewhere doing research for the government. Several times he became absolutely convinced that he had seen UFOs. So, about 1/3 to 1/2 of the class was spend on UFOs and he even brought in "expert" guest speakers. A lot of the evidence looked very credible, but "seeing is believing" as they say.
I swear to God...I swear to God! That is NOT how you treat your human!
His institute seems to have a lot of promising ideas, but no real substance. It has three major projects, one of which relies on the photon thruster and some kevlar straps to toss around satellites, and some sort of undeveloped nano-microscrope.
http://www.baeinstitute.com/
Bullshit, I indeed smell.
How do you get those satellites to slow down, later?
It's a pity they didn't invent this in the sixties. By the time we get to mars with this thing, the planet will already be colonized by sharks...
Because as we all know, it's just that easy! Nothing that worked at one scale ever proved impractical or impossible to do at another!
It's official. Most of you are morons.
It's an advanced concepts grant though. They just throw around money here and there on wacked-out, pie-in-the-sky star trek projects so they can say, "Yeah, we're working on that" to just about any question.
Besides, most of the projects are of the nature that if even one of them turns out to not be total crackpot ramblings, it would change everything (or at least one thing, very dramatically).
That doesn't mean they have any confidence at all of getting useful results. Fortunately, the budget for advanced concepts grants is small and shrinking, I believe.
Can you be Even More Awesome?!
Because until then, you're still paying $10000 per kilogram to low orbit where you can engage the photon drive, which means that no meaningful exploration is gonna happen.
Did I mention that 45 years ago the USAF tested a nuclear thruster that almost reached 1:1? And how fifty-five years ago they drew up plans for an 8 million ton nuclear-driven starship as part of Project Orion?
The aerospace industry has taken notice of a California researcher who, using off-the-shelf components, built and successfully demonstrated the world's first successful amplified photon thruster. Dr. Young Bae of the Bae Institute first demonstrated his Photonic Laser Thruster (PLT) with an amplification factor of 3,000 in December, 2006.
now that the photonic laser is working...
ARM THE PHOTONIC CANNON!!
everyone who got the refrence should shake their heads sadly
I am not a ST fan, but yep thats what most of the inventors admitted.
Imagining that such a high speed is achievable,
don't you think, there needs to be a look-ahead and clearer which would clear space debris.
Is Slashdot really getting to be this slow? Digg had this Monday http://www.digg.com/space/New_Thruster_May_Shorten_Mars_Trip
Isn't "photonic laser" redundant?
Just get Geordi to dephase the aft transporter arrays to match the field variance of the phaser generators until they synchronize with the upper harmonics of the dilithium crystals, then tie that to the deflector array to emit an anti-tachyonic...
Hey, we could just use the deflector shield!
Dammit, I didn't even have a chance to figure out how the impulse engines fit in.
Figures, noone bothered googling the sources in question, check this out : http://www.niac.usra.edu/studies/1047Bae.html
- solar power mass efficiency: I assume a 100%-conversion-efficient solar panel that turns *all* power intersected from the sun into a laser beam. Well, basically, it's somehow a mirror. Indeed, this device already exists, it's a solar sail.
A lot of (generally optimistic) calculations have been done around solar-sailing propulsion; with that you need months just to reach escape velocity. I'd bet travel time to Mars would account in years but maybe I'm optimistic.
Basically, this is the reason why the (otherwise simple and easy to build) solar sails haven't developed up to now: just no interest.
To summarise in our case: because a solar panel delivers at best the power corresponding to the sun solar pressure, don't expect to turn this power to a stronger presure miraculously with a laser.
- nuclear power mass efficiency: There is also a reason why we have quite few nuclear plants turning above. Again it's not unfeasible at all and indeed already flew a couple of time, and dozen years ago, but it is *awfully* less mass-efficient than solar panels in the inner solar system. Basically, it is chosen when sun is too far, like when you go to Saturn with a Cassini spacecraft. On Cassini IIRC you get some 300W from some 100Kg of a reactor. Nasa quite brilliantly manages to run the entire spacecraft with this; go on, plug your laser. This is where you'll get the, what did they say, 30 micronewtons. But maybe less.
To summarise: nuclear power is far less mass-efficient than solar panels.
So? Is TFA completely stupid?
No.
The *way to present it* is stupid. They felt they needed a sci-fi comparison involving Interrrplanetarry Trrravel.
But they indeed have got a microthruster, very precise, that will be extremely helpful for fine-tuning relative positions on formation-flying spacecrafts.
Formation Flying is TEH application.
With it, you can reconstitute a mirror 100 times larger than the Hubble's and it successor's ones, by assembling in flight many smaller (and cheaper) mirrors -this is for instance the purpose of European Space Agency's DARWIN project; you can also create and fly instruments that nobody could dream of before, like 1-km-focal-length telescopes in two separate parts (a definitive need when dealing with X- or gamma-rays).
This optical microthruster may someday be the cornerstone design behind the first X-ray telescope, to get images we never catch on ground (mind you, X-ray are conveniently filtered by the atmosphere to allow life to evolve into Intelligent Design believers).
It is a good idea, and it should quickly be compared with the other microthrust devices currently in (early) development, like ion or electron beaming -it deserves a good technical analysis.
Ah, of course, it's less fun than instant tunneling to Mars...
Herve S.
the weight of the shark on which these lasers are mounted. It all sounds highly plausible now.
Photonic Laser Thruster... perfect. Sounds like it came right out of a pulp Sci-Fi Serial. "Sir!" "What is it Smith?" "The Photonic Thruster, it's out of power! We're dead in the water!"
http://nctn.hq.nasa.gov/innovation/Innovation74/riding.htm
"Reality is that which, when you stop believing in it, it doesn't go away." - Philip K. Dick
Am I the only one getting Buckaroo Banzai vibes from this?
Dr. Bae of the Bae Institute? Seriously?
I went to the Bae Institute's site and found that it is "an independent space and medical research center."
Physics and space science: check.
Institute named after its physicist founder: check.
Medical stuff: check. Dr. Banzai, of course, in addition to being a great physicist, is also a top neurosurgeon. At the Bae Institute site, it says the Institute's medical technologies can be used, among other things, for treating "brain and spinal cord surgeries."
If Dr. Bae is also the leader of a rock band and says things like "wherever you go, there you are," I'll be surprised if we don't see a wave of stories submitted very soon, all by people named named John, saying that Dr. Bae's research cannot be trusted. I expect these submissions to cite the work of another physicist, Dr. Emilio Lizardo.
Laffa while you can, Monkey Boy!
I just showed my age in a way a low Slashdot UID never could.
"It is nice to know that the computer understands the problem. But I would like to understand it too." --Eugene Wigner
Whatever you do, when you meet an alien in space and you are using lasers as propulsion, do not, DO NOT try to back up. This could lead to a serious misunderstanding.
Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly and applying the wrong fix.
I mean really, I could get you to Mars in a week using a "scaled up" slingshot. So what? That doesn't make it practical.
"National Security is the chief cause of national insecurity." - Celine's First Law
This has already been done with conventional chemical rockets. In order for the pluto probe to reach pluto in 11 years, it crossed the moon in a few hours, Mars in a about a week and Jupiter in a month. It woudl be very difficult to put a probe that fast into orbit.
This paper gives the basic idea.
So you are looking at mN/10W, which is dramatically better than previous power requirements of microN/W. If he's got 30x amplification of this, he's improved things by a factor of 1000.
I'd really like to see the current paper, but the above is interesting enough.
DMCA, Hollings, Palladium. What might have sounded like paranoia is now common sense.
http://nlspropulsion.net/
Not necessarily. When you blow stuff up, you're wasting a lot of energy going off in all directions. You could use a containment chamber to help capture some of that and redirect the energy in a helpful direction. But then my understanding is that antimatter "blows up" into gamma photons which are not easy to capture and redirect...
My understanding is that photons are the ultimate in terms of efficient propulsion with the ultimate exhaust velocity. Moreover, lasers can direct all that thrust in a very precise direction. You just have to have a very efficient laser mechanism. And you have to be patient because lasers don't generate a lot of raw thrust.
Privacy Statement: We value your privacy! It is very valuable. That's why we try to sell it whenever we can.
the article was boring, so I had to go for the Uranus joke
Yeah, scaled up a rocket engine could also get them there in a week. What does it take to scale up one of these laser engines to make it suitable for the perceived task?
My experience has been that very large mountains of bullshit have been constructed using PRNewsWire.
I scream. You scream. I assume that means we're both acquainted with the problem. We proceed.
Totally ridiculous idea. You have an engine that can push with thirty-five micro-newtons. Now IF we assume this thing draws just TEN watts, what is the weight of the propulsor plus the ten-watt power source? Probably no less than ten pounds. How quickly will 35 micro Newtons accelerate a ten-pound weight? Very, very very slowly. About 0.00003 of a G, I estimate. And that doesnt allow any weight for the spacecraft, instruments, etc.... You're not going to get to Mars or much of anywhere, not at any reasonable speed with that little acceleration. And no, ganging up more of these doesn't help. Weight, you know.
I forget who wrote that. Possibly Larry Niven. So, we also have an egg-sized military-grade laser. The laser pistol is born. For a .1g or .5 engine, we also have an extremely powerful weapon, that would cause the Russians EUros and Chicoms to protest, loudly.
Will it even get to be developed?
That son of a bitch machine can move like crazy on earth, imagine what it could do in space!
Salut,
Jacques
Of course this idea isn't at the production stage yet - but the inventor of the drive system, Mary Jane Lyle Smith, has secured the patents to the technology and placed them in a trust for further development. It's expected that it'll actually be some time before the new drive system is actually ready - there may be journeys to Mars via more conventional means before then.
---GEC
I'm but the humble pupil, seeking to snatch the scratchbuilt pebble from the master's fully articulated hand
Of course, since he's talking about a laser, it's possible he means to have the equipment on the ground (or moon, or earth orbit) and propel a much smaller craft. With sufficiently focused optics, you could propel a small probe the whole way to mars (in a week? My envelope just ran out of space...), though it would require some pretty heat-resistant mirrors. Fortunately, the energy requirements for that Newton drop by half when you factor reflection into the equation.
I highly recommend the book Accelerando by Charles Stross, which has an extended story arc which deals with exactly this idea. They're trying to get a coke-can sized space shuttle with a solar sail to a brown start about three light years away (which has an intergalatic router nearby), and they power the shuttle with a laser beam powered by a cable dragged through the jupiter atmosphere/magnetic field. I highly recommend the book. Amazing concepts throughout.
He may have been in the same room with one or more representatives (such as a secretary or janitor) of those institutions.
Or he may be dropping names he has absolutely no relationship with. That's how self promotion works.
it could do a round trip in a day...
Meaningless drivel.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
Imagine a beowolf cluster of these...
Your ad could be here!
It's that we don't trust the MBAs running it.
INT: HUGE INDUSTRIAL AREA
A haggard, obviously upset ENGINEER with dark, dark circles under his eyes is yelling at a man with gelled hair in an expensive suit.
ENGINEER
Look, I've been screaming about this for over a year. All that shit is totally burned out.
It's gotta be replaced. That's why the failsafe finally kicked in and shut it down today.
You throw that fuckin' switch, and we're gonna kill everyone in a ten mile radius...
SUIT
Hey, you don't bring that back online, and I'm gonna lose my bonus, so that means you
can't possibly be right. Besides, who ever heard of a nuclear plant having a problem?
And what's a radius?
ENGINEER
I won't do it! Find another monkey to run your crap!
SUIT turns to the H1-B.
SUIT
Apu, get it online.
H1-B
Certainly, sir. Am doing it totally, sir.
SUIT walks out, happy to have proactively solved yet another challenge. SECURITY arrives to strongarm ENGINEER out the door...
ENGINEER
Apu, what the fuck?
H1-B
What am I to be caring about your fat countrymen, stupid American?
Who is going to be on mars to shoot another laser to decelerate you? Am I missing something? Do current missions use the thrusters to slow down or simple orbital mechanics?
or something like that...
Six months ago I had a series of articles that described scaling this up and putting on the breaks and using laser arrays to replace the massive lasers we do not have yet. A pity that more informative articles was less slashdotable than a less detailed press release, but you can see what you were missing now and get answers to questions. I also referenced and corresponded with Geoffrey Landis one of the giants of laser propulsion. I had described how the demo system can be scaled up The demo system used 10 watt lasers. We are completing 100 kw solid state lasers now. We can use arrays of lasers. I have the information on the rapid trip to Mars Putting breaks on the system is something that I have worked out as well You either carry a drive to provide breaking power or you pre-launch the laser array to your destination via a probably slower method. The receiving laser array and power system would then slow you down. The system is a way to achieve the laser pushed sail concepts designed for sending ships and probes to other stars or around the solar system. However, we can use systems that are up to 100,000 times more efficient. Note: laser diode ineffiencies int he 20-80% range mean that the power source has to be a certain amount larger than the laser power needed.
We'll need it for when we meet up with the Kzinti.
I mean, unless you can magically take a straight-line course between the two planets, how do you account for the off-trajectory component of the force exerted by the laser? The ship will be taking it's own course independent of the two planets, which means that the angle between the laser source and the ship will be constantly changing, and the laser will always be off-angle to the optimal.
Is there something I'm missing here? Is there an engine onboard to counteract the excess thrust? Are they planning on having multiple laser installations at different points in space to make this work? Am I missing a simple physics trick?
Man is the animal that laughs.
And occasionally whores for Karma.
Aren't all lasers "photonic" by definition? Was this thing named by the Redundant Department of Redundancy Department?
Downmodding is the refuge of the weak. Don't downmod, make a better argument!
I'm curious, how they will prevent the wake of these ultra-powerful laser beams from slicing through everything in the known Universe. I just hope my house isn't in the path of one of those stray laser beam trails.
I can see it now, and the first casualties are those wonderful communications satellites in orbit.
Mars mission leader: "This is Flash Gordon to Houston. Do you read Houston? We saw a flash, are you there Houston?"
Houston: Silence
Oops!
Maybe Im not understanding or missing something, but couldnt a photonic drive powerful enough to move a ship potentialy also be used as a weapon? Or have I just been reading too much Larry Niven.
and a big one at that.
If it were done when 'tis done, then t'were well it were done quickly... MacBeth
Just turning around does not work. You are being pushed by a laser from a remote source.
You either have to first deploy the receiving laser array and power system.
Or bring an alternative drive for breaking.
Here is my desciption of how to perform this in more detail
http://advancednano.blogspot.com/2007/03/putting-brakes-on-laser-mirror-systems.html
wonder if he had one of these as a kid...??
How to scale up 3.3 billion times.
The original demo was from 10 watt lasers and 3,000 reflections
It is good to actually research original papers to know what is being discussed, so we know what is being scaled.
It is theoretically possible to achieve 100,000 reflections (you may have to go outside the atmosphere to ensure less losses of energy (ie like from a lunar launch system)
We will soon be making 100 Kilowatt solid state lasers. (US military made 67 kw earlier this year and will have 100 kw system done later this year or early next year.
We can use arrays of lasers
(ie more than one). Power is provided in electrical form to the lasers. Say from nuclear power (3.2 GW twin reactors, and can have more reactors) or hydro power (Three gorges dam generates 18 GW). So wattage can go up say 100 million times to 1GW. (reduced the nuclear plant power by inefficiencies of converting electricity to laser power.)
The reflections can increase by 33 times.
Therefore, 3.3 billion times more power.
Thus you can send several ton vehicle to Mars at high speed http://advancednano.blogspot.com/2007/02/use-67-kilowatt-solid-state-lasers-for.html
What the media doesn't tell us is that in 2004, the worldwide death toll among coal miners was a whopping 21,500!! (Most of the accidents happened in China.) That's as many deaths, every single year, as seven World Trade Centers stacked atop each other.
Contrast the coal industry with the nuclear power industry; in its entire history, there's been only one incident with fatalities. (Chernobyl, a reactor that was orders of magnitude less safe than modern designs, killed 31 people. Divide that by the 50-year existence of the nuke power industry, and you get an annual death toll of 0.62 persons.)
If all coal-fired power plants were converted to nuclear, we'd immediately surpass the goals of the Kyoto Protocol. Environmentalists spend a lot more time criticizing nuclear power than coal; the facts show they are barking up the wrong tree. Even when they criticize coal, they do so for the wrong reasons - like acid rain, which pales in comparison to the massive death toll among miners.
That that is is that that that that is not is not.
This works by reflecting laser light between mirrors.
Amplification is achieved by the number of times light is reflected between the mirrors.
The best mirrors can achieve 100,000 reflections
I am curious as to why I am practically the only one who actually is providing information on how this actually works, yet I do not get any score boosts ? I guess it is because none of the modders can actually recognize correct answers.
I also had submitted articles with complete information on this back in February and the editors did not choose to publish more informative information.
Seriously just take a look at the information that I have assembled and presented with pictures and references.
Comments from Geoffrey Landis (Nasa guy who wrote a lot of seminal papers on laser propulsion.)
You can actually find out what this is about instead of just parsing a press release.
http://advancednano.blogspot.com/2007/02/photonic-laser-propulsion.html
http://advancednano.blogspot.com/2007/02/use-67-kilowatt-solid-state-lasers-for.html
http://advancednano.blogspot.com/2007/03/putting-brakes-on-laser-mirror-systems.html
The demo system used a 10 watt laser.
We can build 100 kw solid state lasers
10,000 times more powerful
We can build more than one laser and they can work in an array
We just need to power the lasers with electricity
There is an efficiency loss converting electricity to laser power
There are wavelengths that can easily go through the atmosphere (it is how we still see faint stars)
All of the laser pushed solar sail ideas can be made 100,000 times easier because of the reflections.
We can also use reduced laser size.
Please read the articles and you could actually have an informed discussion about what this is all about
Here is the link to the Geoffrey Landis (Nasa) and Robert Metzger paper on multi-bounce laser sails.
http://www.rametzger.com/nonfic-mblbs.htm
The effect you describe is a relativistic effect. It becomes relevant at high velocities, a significant fraction of the speed of light. Constant acceleration has already been employed by ion thrusters such as those used by Deep Space 1. The topic of this thread, getting to mars in a week, makes for an interesting press release, but the technology is really more interesting. It's presumably offering a much higher specific impulse, allowing a wider range of mass trade offs than possible with engines that have a lower specific impulse. Lower thrusts and slightly longer trip times would still be dramatically shorter than the six months (or longer) trip times discussed for other plans (i.e. Mars Direct plans an eight month transit time to Mars). The photon engine technology could be applied, for example, to a trip plan that featured a six week transit time to Mars, reducing the engine and power plant mass.
Unfortunately it isn't clear how the technology described would be applied to a Mars type of mission (e.g. any non-formation-flying mission where the photon engine would be used to provide significant and arbitrary velocity delta for solo ships. The "thrust" appears to occur between the mirrors, which the good doctor apparently plans to place on different spacecraft for stationkeeping. Perhaps one of the mirrors could be mounted on the moon or something. Dunno. The details seem to be absent. You would think this could be explained in a way that we geeks could understand. "Amplifying" chambers. Yeah. Right. Zero mass. Amplify that all you want and you still get zero thrust.
1) Use the sun on the acceleration half of the trip. Solar sails are not very heavy.
2) Take your time. Accelerate on the sun to just fast enough to get there in 2 weeks, or a month. Then you only need the nuclear reactor to decelerate.
3) Nuclear reactions generate more than heat. Is it possible to take the light given off by the reaction to partially provide light to the laser? If so that could be a dramatic increase in energy efficiency of the reactor.
Those numbers are very high, but you don't need them to get to Mars. Assuming 1 and 2 work, you might get there on 2 * 10^12 watts, or 2,000,000 megawatts. Or really, you might get there for free and LIVE because of 2million megawatts firing to slow you down.
If 3 is true then you're that much closer to delivering all that energy, but it's still an amazing amount of electricity. Can a nuclear core deliver that in a few days' time?
You realize that once you lift a robot and this new laser rocket into the stratosphere on a really big balloon (or a solar plane), you could reach the moon on a budget.
And then you could phone up Google for $50 million bucks.
And I bet that prize is collected within 7 years.
I wasn't suggesting the idea as a whole was bullshit, just that this particular doctor was full of it.
Speaking of MacNuggets ... at that speed
hitting one could mess with your bodywork and
generally create a real long 'bad hair' day.
RR
Could this technology be used for terraforming Mars?
Just send some nuclear-powered lasers out to Saturn's moons, and attach some of these cavity-setups to large chunks of floating ice nearby, and laser-propel the chunks over into Mars' orbit for collision. Mars could do with a little more ammonia in its atmosphere to make it more livable for us, and Saturn's rings have plenty of that stuff.
Hold on, to scale up a trampoline jump by 15.6 million, wouldn't that mean the trampoline would have to be 15.6 million times as big and you'd have to fall 15.6 million times as far to gather the same energy? If your trampoline is 10 feet wide now it would have to be nearly 30,000 miles wide, and if you're falling 3 feet now (you'd also have to put 15.6 million times as much effort into the rebounding jump, BTW, so you better start working out) you'd have to fall 8,863 miles (nearly 37 times further from earth than the ISS, with earth-gravity acceleration all the way down, ignoring terminal velocity...good luck on that one) onto your new trampoline with a diameter nearly 10 times the distance from NY to LA and push off with enough force to make Superman and Super Saiyan Goku put together look like an anaemic little girl.
I'll put my money on the photonic frickin' laser thruster TYVM.
"When information is power, privacy is freedom" - Jah-Wren Ryel
http://en.wikipedia.org/wiki/New_Horizons
The probe left Earth on January 11, 2006, passed Mars on April 7, 2006, and passed Jupiter on February 28, 2007. That's almost 3 months to Mars and a little over a year to Jupiter, not a week and a month, respectively, as you claim.
Well, 1 week eh? What if just as you're getting up to speed there's a small chunk of meteor in front of ya? Who ya gonna call, GhostBusters?
Unless of course the Rocket was running linux then it would be three weeks
A week searching for a distro that actually does what you want, a week looking for drivers compatible with that distro so it actually works, and then a week to mars, stopping everynight for numerous unknown errors you have to fix yourself because there is no active support base
If as you stated this craft is capable of one G acceleration, then you must also know that there is nothing magic or limiting about a single G. You could make it more powerful as well to the limits of your energy generation rate, bearing in mind that acceleration depends on a square law- twice the acceleration requires four times the energy to achieve it less inefficiency losses. Therefore, your starship can take off from the earth without benefit of expensive and wasteful chemical 'rockets', and that guy from the University of Hawaii can go back to 'space cadet' school for re-education.