Arrays of lasers can be used to push light weight solar sails to other stars. This has been funded with over $100 millon and it builds upon the technology of the $600 billion laser and photonics industry. A recent paper looks at how different technological improvements will make it more feasible and improve the costs. Integrated photonics and mass production of most of the modular systems will be fundamentally necessary to afford the full-scale realization of this vision. Researchers have derived an analytical cost model which is driven by the fundamental physics of the proposed system. This allows us to make economically informed decisions and create a logical path forward to interstellar flight.
Large scale directed energy offers the possibility of radical transformation in a variety of areas, including the ability to achieve relativistic flight that will enable the first interstellar missions, as well as rapid interplanetary transit. In addition, the same technology will allow for long-range beamed power for ion, ablation, and thermal engines, as well as long-range recharging of distant spacecraft, long-range and ultra high bandwidth laser communications, and many additional applications that include remote composition analysis, manipulation of asteroids, and full planetary defense. Directed energy relies on photonics which, like electronics, is an exponentially expanding growth area driven by diverse economic interests that allows transformational advances in space exploration and capability. We have made enormous technological progress in the last few years to enable this long-term vision.
In addition to the technological challenges, we must face the economic challenges to bring the vision to reality. The path ahead requires a fundamental change in the system designs to allow for the radical cost reductions required. To afford the full-scale realization of this vision we will need to bring to fore integrated photonics and mass production as a path forward. Fortunately, integrated photonics is a technology driven by vast consumer need for high speed data delivery. they outline the fundamental physics that drive the economics and derive an analytic cost model that allows us to logically plan the path ahead.
For relativistic flight (over 10% of lightspeed) development of powerful lasers to push ultra-low mass probes is needed. Recent developments now make both of these possible. The photon driver is a laser phased array which eliminates the need to develop one extremely large laser and replaces it with a large number of modest laser amplifiers in a MOPA (Master Oscillator Power Amplifier) configuration with a baseline of Yb amplifiers operating at 1064 nm. The system is phase locked using a coherent
beacon that is either carried by the spacecraft or reflects off the spacecraft. Maintaining phase integrity is one of the key challenges. This approach is analogous to building a super computer from a large number of modest processors. This approach also eliminates the conventional optics and replaces it with a phased array of small low cost optical elements. As an example, on the eventual upper end, a full scale system (50-100 GW) will propel a wafer-scale spacecraft with a meter class reflector (laser sail) to about c/4 in a few minutes of laser illumination allowing hundreds of launches per day or 100,000 missions per year. Such a system would reach the distance to Mars (1 AU) in 30 minutes, pass Voyager I in less than 3 days, pass 1,000 AU in 12 days, and reach Alpha Centauri in about 20 years.
The same system can also propel a 100 kg payload to about 1% of lightspeed and a 10,000 kg payload to more than 1,000 km/s, though there is a practical trade space of using DDM vs IDM for larger mass spacecraft.
There are other applications for large laser arrays and long range power beaming. Power can be beamed power for ion engine systems, distant spacecraft recharging (eliminating RTG’s in some cases), full standoff planetary defense against both asteroids and comets, solar system wide active illumination or laser scanning (LIDAR) to find and study smaller objects, asteroid manipulation and composition analysis, terraforming applications, and a path to extremely large telescopes.
Beaming power to power ion engines, enables high speed maneuvering beyond Jupiter.
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
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A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.
Interesting point about the demand for data transmission driving the development of tech to apply to something completely different like a method of space travel. I suspect the vision will also benefit from additive manufacturing becoming more like exponential manufacturing, such as depositing some special goo on an asteroid that converts the whole asteroid into a fully functioning solar panel in about a month, which then checks itself into a whole network of directed-energy panel-asteroids.
Also keeping in mind that space travel was still a distant dream when a kid named Hohmann started pouring a sidewalk to the planets that we have walked on…
With the thousands (Soon to be tens of thousands) of active satellites in earth orbit, how could a directed energy laser beam possibly miss all of them?
Thinking of Starlink, OneWeb, Kuiper, etc…
Once we have laser-based flight, we should begin recruiting tartigrade astronauts.
Brian, thanks for an article an amateur can understand. And thanks for your dedication to science: it enriches us, as does the debate you triggered.
What’s the amount of energy needed for 1kg accelerated to 1/10 of 299792.458km/s (diameter Solar System ~0.00127l.y.=~11.1lhours, ~3.33*10E-6s/mm, 0.075m=~3″ on 4GHz cpu clock cycle) compared to 1kg of H2 towards electricity->laser with predicted efficiency of theoretical H-H fusion reactor?
(fusion to direct beam?)
It takes 907.8 TJ to accelerate 1 kg to 10% of c (K = (γ-1)mc²).
The proton-proton chain turns four hydrogen atoms and two electrons into one helium-4 and two neutrinos, releasing 26.73 MeV of energy. 1 kg of hydrogen contains 500 mol of molecular hydrogen, or 250 mol of the inputs to the reaction.
The energy generated is then 26.73 × 1E6 × 1.6E-19 × 250 × 6.022E23 = 643.9 TJ. Dividing the two, one kilo of hydrogen provides approximately 70.1% of the energy necessary to accelerate one kilogram to β = 0.1.
Very nice hand calc.
Looks like 1kg of 235U has enough energy to achieve 1kg@2%C using 25% conversion efficiency… wow. No wonder all the scifi talks about anti-matter. LOL.
We’re stuck on this rock, but it’s a spaceship itself.
Thanks for the pointers.
From a different POV, numbers predicting ITER electric output being ~0.4 of D-T fusion reaction ( ~10GWh/kg for D-T_el)
For accelleration of 1kg to β=29979245.8[m/s]*299792458[m/s]^(-1)=0.1 with a 50% efficient laser beam there’s ~250GWh energy requirement. With ITER fusion device resources necessary are ~10kg Deuterium and ~15kg Tritium (without energy for extraction/supply).
On β=0.02 accelleration mass of 1kg theoretically equals 1kg D-T fuel.
With some large diameter mirrors (8m, spaceship compatible) in high orbit, this could be useful against incoming ballistic missiles…. (see SDA, 1980s).
Oumuamua 100kg spacecraft mission, please.
Such a spacecraft could reach it in a matter of months.
Current proposals for a mission with conventional means have timelines of over a century
At this point it might be easier to flag down some aliens and trade them cow pies or something for space drive technology.
I hope it works, but midcourse corrections and deacceleration will be problematic.
I get how it is possible to accelerate to these speeds.
How would you slow down??????
e-sails
https://www.researchgate.net/publication/304871995_Combining_Magnetic_and_Electric_Sails_for_Interstellar_Deceleration
What would be the consequences of having this much laser interaction with our atmosphere be, I wonder.
We currently have about 18000 gigawatts of power generation. The thermal power (coal, natural gas, nuclear) have 60-70% waste heat. The lasers running in the atmosphere would have some waste heat. But most of the lasers would be at wavelengths that go through the atmosphere. If it is going through then it is mostly not interacting with the atmosphere. Possibly some instant fried birds. But it would be short bursts of power with minimal interaction. 100 GW is not that big a deal.
Turn around
Is there any chance we could be informed as to the criteria on which comments do and don’t get posted? Length limits, for instance? It seems nearly random.
I am not doing anything to limit comments. I am approving every comment from you and any other non-spam comment. I do not see any rejected comments. You Brett are whitelisted. If anything is being dropped please have a copy of your comment in say another text editor and copy and paste it to submit. If it somehow fails then email me blwang at gmail dot com and I will be able to talk to my developer. Otherwise I have nothing to track.
Well, I have this site completely white listed on my end, too.
Based on the random behavior I’m seeing, my guess would be there’s a race condition between the page refresh triggered by hitting submit, and the process of uploading the comment.
A race condition! Yes, that explains… well I don’t have enough data to see if it explains this comment system.
But it DOES explain the OTHER website I’m getting comment issues on.
Brian this is an amazing story IMHO. I have 3 daughters and 3 grandsons and I am looking forward to seeing the next stage of interplanetary travel in their lifetime. Great read and a huge thank you to from Edmonton Alberta Canada
That’s not true. I once criticized your worshipping of Elon Musk and Tesla and I have been banned from the comments section ever since.
Should consider using the sun. You won’t reach 10%C but it would be a lot cheaper. Build it as a two stages. The first stage is to get you as close to the sun as possible. The second stage sail would then unfurled and it would accelerate rapidly.
Fortunately, a solar sail is much the same technology, at least as far as the probe and sail are concerned.
So you’ve got multiple projects working on the tech, some for laser sails, some for solar. The result should be faster development overall.
The multiple applications in different domains suggest this is a probable path to early interstellar missions as well as advanced telescopes that would map out and discover details about all the exoplanets for dozens of light years in every direction.
Would it be cheaper, easier, more efficacious, to use a mirrored array in space to concentrate constantly abundant solar energy, and send the resulting pointed light to a solar sail spaceship? It might have longer reach too since the sun’s photons currently extend well beyond our solar system. It should have less energy requirements as well.
Sunlight is incoherent, which strictly limits how sharply you can focus it. You’d need a mirror larger than the Sun to get a decent beam density for enough distance to do interstellar launches.
Use it to send probes to the Kuiper belt and scattered disc. If it works for that, then scale it up for interstellar missions.
Any serious attempt at interstellar flight would need something above 10% c.
That’s ~47 years to Proxima, which is technologically feasible with known technologies (RTGs and solid state automation).
Anything below that, and the travel time becomes of purely abstract interest, or sci/fi.
But sending chip sized probes would be very disappointing too, working as PoC only. You need to stack up the pounds for anything really interesting to happen. And that means quite more powerful lasers.
Nevertheless, lower speeds are of definitive interest for solar lens gravity missions.
“Any serious attempt at interstellar flight would need something above 10% ”
Fifteen/20 years ago this sort of thing might have got my motor racing; but now seems everything is on hold waiting for our “masters” to tell us about reverse engineered Tic-Tac UAP technology. I mean 60K feet to ~200ft in less than half a second; obviously we are talking about some kind of space warping. Compressing space in front of the craft expanding it behind said craft; probably with a superluminal application.
Our “masters” may not have been able to reverse-engineer any tic-tacs which happened to get into their hands in good enough a state to study, though. Even people as smart as Newton or Pascal might not figure out the functioning of an integrated circuit, if one were to go back in time to the mid-17th Century.
It’s all very well to be sceptical of what the government tells us, but there is a fine line between this and the people who posit Ancient Astronauts because those ancient Egyptians could not possibly have built the pyramids by themselves.
“Our “masters” may not have been able to reverse-engineer any tic-tacs which happened to get into their hands in good enough a state to study, though”
Agreed; a problem no doubt exacerbated by the secrecy. Instead of a global cooperative effort pooling our resources. I believe that investigative journalist George Knapp claims to have been told the US government is supposed in possession of one or more intact craft.
To your point I agree that for instance Ben Franklin and a team of craftsmen would have been very hard pressed to “reverse-engineer” an intact F-35 fighter in their possession even with “unlimited” funding. Doubt if even after ~50 yrs they would be able to; however bet we would have likely developed heavier-than-air craft/electronics many decades ahead of when we actually did. My point is that if this is real then it makes far less sense to invest significant intellectual and or physical resources in trying to build things like laser pushed light sails to Proxima Centauri.
Sorry… Are you saying the ancient Egyptians could not build the pyramids or are you mocking those that say such nonsense?
That the technology existed to make the pyramids and the Egyptians utilized it well, is so commonly known that we don’t need Erich van Daniken to tell us only aliens could build them.
Sorry – Erich von Daniken.
No, the ancient astronaut theory is strictly meant as an example of too much scepticism. Of course the Egyptians built their pyramids, as have the Mayans.
Not a good idea to expect for miracles to show up.
Even if they are real and some governments have a few on their hands, UAP’s technology can be completely incomprehensible for us, and remain so or centuries to come.
Knowing they exist can indeed inspire us (reactionless drives and FTL exist, yay!), but also hinder us in our search for alternative solutions, expecting the supposedly known ones to just be copied or handed over by the space brothers.
Humanity has never advanced by waiting for anything to be handed over to us by anyone. And alien civilizations probably respect and encourage that impetus.
We need to act and do our own stuff by ourselves, or risk waiting forever.
“Not a good idea to expect for miracles to show up.”
I agree there are potential downsides to advancing by merely copying/reverse engineering someone else’s tech rather then developing it on our own. However if they are flying around in our skies (and seas) with impunity to say nothing of abducting our citizenry/interfering with nuclear missile silos we need to come up to speed technologically as quickly as feasible. No telling what their agenda actually is; maybe not overtly hostile (or we would be extinct already) but not necessarily serving our best interest. Faster we can close the gap technologically the better for us. I don’t like the idea of us being someone’s lab rat.
This teally is the only thing that would get people and and supplies accross the galaxy. …. faster u travel means endless power. Folding space time is the only possible means to go any near by galaxies.
Best sf short story on this subject: “The fourth profession”, by Larry Niven.