Guest essay by Eric Worrall
An American scientist has made a remarkable conceptual breakthrough, a design for a non nuclear relativistic launcher, capable of accelerating thousands of deep space probes per year to 0.25C; fast enough to reach the nearest stars in 15 years. The system is extremely scalable – you could start with a small, low cost proof of concept launcher, and work up to bigger devices, capable of launching substantial probes into interstellar space. The system also has a practical alternative use – the full size version is powerful enough to deflect dangerous asteroids into safer orbits. The design uses mostly off the shelf industrial laser and optical technology.
The abstract of the study;
In the nearly 60 years of spaceflight we have accomplished wonderful feats of exploration and shown the incredible spirit of the human drive to explore and understand our universe. Yet in those 60 years we have barely left our solar system with the Voyager 1 spacecraft launched in 1977 finally leaving the solar system after 37 years of flight at a speed of 17 km/s or less than 0.006% the speed of light. As remarkable as this we will never reach even the nearest stars with our current propulsion technology in even 10 millennium. We have to radically rethink our strategy or give up our dreams of reaching the stars, or wait for technology that does not exist. While we all dream of human spaceflight to the stars in a way romanticized in books and movies, it is not within our power to do so, nor it is clear that this is the path we should choose. We posit a technological path forward, that while not simple, it is within our technological reach. We propose a roadmap to a program that will lead to sending relativistic probes to the nearest stars and will open up a vast array of possibilities of flight both within our solar system and far beyond. Spacecraft from gram level complete spacecraft on a wafer (“wafersats”) that reach more than 1⁄4 c and reach the nearest star in 15 years to spacecraft with masses more than 105 kg (100 tons) that can reach speeds of greater than 1000 km/s. These systems can be propelled to speeds currently unimaginable with existing propulsion technologies. To do so requires a fundamental change in our thinking of both propulsion and in many cases what a spacecraft is. In addition to larger spacecraft, some capable of transporting humans, we consider functional spacecraft on a wafer, including integrated optical communications, optical systems and sensors combined with directed energy propulsion. Since “at home” the costs can be amortized over a very large number of missions. I n addition the same photon driver can be used for planetary defense, beamed energy for distant spacecraft as well as sending power back to Earth as needed, stand-off composition analysis, long range laser communications, SETI searches and even terra forming. The human factor of exploring the nearest stars and exo-planets would be a profound voyage for humanity, one whose non-scientific implications would be enormous. It is time to begin this inevitable journey beyond our home.
Read more: http://www.deepspace.ucsb.edu/wp-content/uploads/2015/04/A-Roadmap-to-Interstellar-Flight-15-h.pdf
NASA spends around a billion dollars per year on GIS climate research. The GIS budget was reviewed in 2011, on the grounds that they are duplicating work done by NOAA/NCDC, but the GIS budget survived the review.
A billion dollars per year would go a long way towards funding a pilot laser launcher program. Given the linear scalability of the proposed system, ongoing funding of this magnitude would allow progressive scaling of the prototype into a full size launcher.
Dr. Robert Forward used laser propulsion in his sci-fi novel series “Rocheworld”, the details are well worked out in there- including how to stop.
Tantalizing. But does anyone have a sense of how space particles might affect absorptivity? It seems that thermal issues could be significant if sail absorptivity can’t be kept exceptionally low.
Note also the “stability and shaping” issue raised on page 22.
Or how space particles might effect the wafer-sized ship?
It seems a difficult task. If the laser drives are satellite mounted in earth orbit, then an equal and opposite beam will be required to maintain the satellite’s orbit. Multiple gigawatt beams increase risks to us earthings.
The wafer scale devices 2g or less, complete with nuclear power source, appear to have the greatest chance of ‘getting somewhere interesting’, but how can we get comms from such far distances, in such a small envelope, with so little power?
I suppose it can be said that if we aim in the right direction then the device must have reached the target and to doubt the achievement it is just being ‘negative’ – a bit like dismissing some of the outlandish climate stories!
Well, I read the pdf. BS-phd is my opinion of the piece. An armchair speculation for a sci-fi piece that has never really examined the technology that this is based on. I would suggest a real understanding of Laser energy dispersal would be the end of this speculation…pg
Could you elaborate?
I’m quite receptive to the idea that the concept has rubber-meets-the-road problems, but it didn’t appear that the author was relying on the probe’s subtending any individual the laser’s beam waist; he seemed to be relying only on the lasers’ phase relationships’ approximating those of a lens, and he then employed the diffraction limit to determine how well the radiation would be concentrated.
Could you further explain how that is inconsistent with “Laser energy dispersal.”
The math is arcane and I don’t have it readily to hand, but it turns out that a laser beam can project a “waist” only out to a certain distance (near field), after which it grows in accordance with the inverse-square law (far field). Moreover, diffraction allows some of the radiation to spread farther out in rings.
I haven’t read the proposal (seen too many of its like already), but I surmise that they haven’t really taken account of the physical limitations on laser beam propagation. It’s a common failing of such schemes.
Michael J. Dunn:
You’re correct that the waist length is limited and reduces with waist area. But the point I was making is that the author did not seem to be relying on the waist’s extending out to the probe; he proposed instead to use a phased array: an array of lasers focuses on the probe, producing the effect of a large lens.
Oops! I misspoke. Beam-waist length increases with waist area, of course. I had said it decreases.
For Joe at 28 Mar, 2:43 PM–
A phased array of lasers is yet another pipe dream. Huge problems associated with that, specifically having to do with phase control. Which involves the laser wavelength stability. Which is limited by the variation induced by the fact that the photons originate from inherently transient sources (truly continuous-wave sources will have near-zero variation in wavelength).
In any case, it hardly matters. The distance at which a “waist” can be projected is not by any means interstellar, so long as you are using array apertures that are not larger than a planet. Figure it out. The equation for the distance to the beam waist is zmax = pi * w^2 / 2 lambda, where w is the beam radius at the waist and lambda is the beam wavelength. The beam radius at the waist is 70.7% of the radius of the source aperture.
You mean to say there are conceptual ways to fire thousands of probes to nearby stars and all over our own solar system, collecting much needed data advancing astronomy, science and engineering and even supplying planetary missions, and these concepts never get funding or off the ground? ya don’t say!!
It could be an exciting time for astronomy and science, how many much needed well paid jobs would be created having a developing space industry based around working concepts like this one?
But for the foreseeable future the fact is, we are stuck with political scientific hacks screwing around with data, boring the life out of ‘man made global warming sceptics’ across the planet for no other reason than to financially burden the less well off with heavily inflated energy bills, lowering industrial production and throwing away jobs all in the name of the latest political fad…
I really don’t want to be on this planet when I think about it, can I be put on one of these laser accelerators? lol
Well if this ever happens I hope they do a good job with their security & comms software.
Otherwise we might find the bad guys hack into it and start vapourising people they dont like
This sounds like a good way to explore our solar system relatively quickly, once it got up and running. We could put a probe around every significant body in the solar system, in our lifetimes. I like the thought of that. It’s the kind of thing where you can start out small and build from there. I would put money into it if it were up to me, whether it came out of the climate change budget or not.
It sounds amazing doesn’t it? It’s just more fluff…
Where is Bob Newhart when you need him?
I can’t believe the naysayers on this thread—and on a science blog, no less! I skimmed the paper, and noted that the author carefully discussed many of the potential problems with the concept mentioned here, e.g. how to brake (no solution), how to communicate data from the distant star (some possiblities), how to minimize the danger from interstellar ‘dust’ (some ideas), etc. Yes, it is not a new idea, but the point that the technology—phased lasers, miniaturization, etc.—is now within our grasp is new, and welcome.
When I was a kid, lying on the summer grass gazing up at the stars (which one could see in suburban Montgomery County, Maryland much better than today), I assumed that by the turn of the century we would be on our way to Alpha Centauri. But here we are still, stuck in low-Earth orbit, and fretting about going back to the Moon, and to Mars. Frankly, I am getting impatient, so let’s get on with it. And as for you “Man was never meant to fly” Luddites, back in your caves!
/Mr Lynn
Writes L. E. Joiner:
You don’t get it yet? It’s because this is “a science blog” (no less) that those who write, read, and comment here have great scientific literacy and familiarity with the federal bureaucracy’s politicized approach to scientific investigation and technological development.
Knowing what we know – in many of our individual cases on the basis of direct experience with “government science” in the various tax-funded federal agencies – how the hell else d’you expect us to regard what is either being proposed as Yet Another Boondoggle or is almost inevitably going to come into being as Y.A.B. by the career mediocrities of Obozo’s Islamic World Outreach Department?
Yes, “government science” is to be regarded with a jaundiced eye, but you paint with too broad a brush. NASA has done some wonderful things, especially in the realm of astronomical and interplanetary research with telescopes, probes, rovers, and other space vehicles. I see this line of inquiry as an extension of that realm.
/Mr Lynn
Protests L. E. Joiner:
Even granting these “wonderful things” accomplished under NASA’s aegis, what you subjectively perceive as benefits accruing by way of spending power and other resources put into play “in the realm of astronomical and interplanetary research” by this agency over the decades, you must come to grips with the iron law of bureaucracy, which Dr. Jerry Pournelle put pretty pithily many years ago:
Were that not enough, being the creature of the federal executive branch, NASA is wholly the tool of whatever creature currently flatulates into the big comfy chair behind the Resolute desk, and have we not yet ample appreciation of how the current occupant thereof has proven that any such imposition of malicious political priorities upon the sciences will invariably make of this and other agencies of the executive nothing more or less than engines of usurpation, duplicity, graft and corruption?
Re Tucci78 March 28, 2016 at 2:29 pm:
I would welcome a regimen that would enable us to undertake expensive interplanetary science (and any other kind) with no risk of bureaucratic ossification and with complete independence from political tentacles, but must confess that it is hard to see how to achieve this utopian system.
More broadly, the Founders really did not envision a fourth branch of government, an entrenched bureaucracy that essentially operates as a law unto itself. Conceivably a Convention of States (as Mark Levin has proposed) could rein it in with Amendments, requiring ‘sunsetting’ and new enabling legislation, but how that might affect quasi-autonomous agencies like NASA remains to be seen. Arguably the Federal government ought not to be involved in scientific research (or space exploration) at all, but it will be as long as we need a national defense, willy-nilly.
/Mr Lynn
L. E. Joiner writes:
During the conflicts of the 20th Century, militarized technology came to widespread consideration as conferring perhaps the critical “edge” in strategic, operational, and tactical planning and execution. World War II has been spoken of as “the war of the boffins, and with good reason. Scientific advances manifest as functional “milspec” engineering made the difference between defeat (or disaster) and success (to one degree or another) time after time.
As World War II segued without effective interruption into the perpetual state of Cold War between the First World and the Second (i.e., the Soviet Empire and the other authoritarian Communist powers), the boffins were perceived – correctly – as military assets, with the West having the advantage in both economic power to “push” endeavors in STEM and in the commercialization of technologies “spun off” from military research & development. The glory days of NASA were an unintended (but politically very welcome) consequence of the extension and intensification of the “Boffins’ War.”
To the extent that “pure science” endeavors as well as scientific investigation manifestly applicable in the development of technology continue to prove vital to government’s only legitimate purpose – as the agency to which the citizenry delegate their unalienable individual human right to exert deadly force in retaliation against violent aggression (the “breaking things & killing people” function of the police power in civil society) – agencies such as NASA have defensible reason to exist.
But only to the extent that NASA operations result in “force multiplier” functions accruing to U.S. military capabilities. If there’s justification for “blue-sky” pure astrophysical research, it’s better that the work be funded by other means than tax revenues, and removed utterly from the purview of GS-whatever sphincters controlled by graft-sucking jacks-in-office and other enemies of our republic, emphasis on our “good Muslim schoolboy” Indonesian-in-Chief.
You’re so full of shit.
Writes Sparks (I’m paraphrasing):
Let’s see what happens as this post undergoes moderation.
[Well, it went to moderation. And? .mod]
Writes Tucci78 March 29, 2016 at 2:21 am:
I don’t disagree. But it would be a stretch to find the funds for expensive space probes like Pluto-faring New Horizons ($700m) in the Defense Department budget, and it is hard to know where else they might come from—private Silicon Valley foundations? A Kickstarter campaign? I’d rather my tax dollars went to space exploration than most of the other frivolities never authorized by the Constitution.
Then, ‘pure’ academic science in general has become so firmly wedded to the teat of government (taxpayers’) grants that weaning would be traumatic. A biologist I know reacted in horror: “Who else would pay for research?” But it can be argued that a lot of the ‘research’ has little point other than the generation of resumé fodder and employment for post-docs who can’t find teaching jobs. Might be interesting to shut down the NSA and the NIH and see what happens. But this is a large topic for another day.
/Mr Lynn
L. E. Joiner observes that
It would be a “stretch” because projects like the New Horizons probe are of no arguable military utility, which means that they don’t accrue to the “breaking things & killing people” function which is (as I and Thomas Paine have both observed) the only reason why we (the private citizenry) don’t simply kill the governmentally inclined out of hand as a public health measure.
To the extent that government is allowed to exist, the “goons with guns” role is the institution’s only real justification. Goshwowboyohboy “big science” – except as it facilitate better thing-breaking and people-killing in defense of the Constitution against all enemies foreign and domestic – ain’t something that we should ever entrust to the governing class and their myrmidons.
Simply because “that’s the way it’s been” since the Good War is no friggin’ reason whatsoever to continue throwing pelf and manpower down a succession of ratholes defined by professional grifters, grafters, thieves, power-trippers, sociopaths, psychopaths, and vacuities with Civil Service ratings.
The fact that “big science” researchers (like your biologist buddy) have become utterly dependent upon stolen money (and what the hell else is taxation but theft?) to pursue their investigations ought to clue you and everybody else reading here in on the fact that the perverse incentives imposed by the politicians’ command and control are no more healthy for the sciences than is trailer-cooked methamphetamine for the average high school student.
((Okay, enough with the Ritalin jokes already….))
Any reason why my thoroughly innocuous comments are going to moderation? Aside from inspiring one ‘Sparks’ to vulgarity, I mean?
Asks L. E. Joiner:
Durned if I know. I’ve been on “permanent double-secret probation” for more than a year myself.
I suspect it’s for the crime of eloquence.
I just don’t understand this attitude. If all you are looking for is a relativistic projectile then this technology is perhaps onto something and may be possible to develop. If you want a probe which can be inserted into orbit then until you have a braking solution – or at least a ghost of a practical idea – it’s as much use as an ashtray on a motorcycle. It’s no good dreaming of our sci-fi fueled youths and boldly exclaiming that if people hadn’t tried stuff in the past we wouldn’t have got anywhere. People guessed that man might fly because all manner of other creatures were doing exactly that. Research doesn’t start with ‘well I’d like to have some currently impossible thing and I have no idea how that currently impossible thing might be achieved but I’m damn well going to sit here researching away until I do – so there!’ What you need is some sort of idea to start with. If everyone sat around bashing their skulls against problems with no glimmer of a solution or even in which direction to look for that glimmer on the principle that with sufficient effort they would get there sooner or later we really would never have got anywhere.
Old story. I did a mission analysis (in the 1980s) of an interstellar mission and arrived at the conclusion that the mission duration should take no more than 50 years, in order to be sustainable from a funding and project management standpoint. Skipping a lot of math, this resulted in the derivation of a requirement for a propulsion system that could produce about 1 million seconds of specific impulse. It turns out that such technology exists (look up Birkeland rays), The problem, always the case with high-specific-impulse reaction drives, is that a high kW/kg power supply is needed.
Another approach is direct application of continuous nuclear fission reactions…much more to my taste!
I’m surprised that no one, to this point, has mentioned the Orion nuclear explosion drive system. Dramatic and controversial, but not controversial as to its efficacy. It would work. If we are serious about actually GETTING THINGS ACCOMPLISHED, we will throw over our taboos and prejudices and get on with the show.
Michael J. Dunn
There’s a job for you, we need a way to send probes across our solar system and to nearby stars. There have been no practicable experiments to date, which is strange.
@Sparks March 28, 2016 at 5:54 pm
Thanks for your contribution.
😉
L. E. Joiner Says:
“…Aside from inspiring one ‘Sparks’ to vulgarity, I mean?”
You’re just so inspirational, next time wear your big boy pants, lol no offence intended toward you though honestly…
Nitpick, but should use lower-case c for the speed of light. When I read .25C it looks like a temperature.
Shut up lol
Ugly to a physicist’s eyes. Irrelevant to probably anyone else.
From the article: “Braking to Enter Orbit on Arrival – A very difficult challenge is to slow the spacecraft to typical planetary orbital speeds to enable orbital capture once arriving. This task is extremely difficult as the
initial entry speeds are so high (~ c) and the orbital speeds are so low (~ 10-4 c). Dissipating this much
energy is challenging. We have considered using the stars photon pressure, the stellar wind (assuming it
is like our own solar system), using the magnetic coupling to the exo solar system plasma. None of these
techniques appears to be obviously able to accomplish this task and much more work and simulation is
needed. A simple fly-by mission is clearly the first type of mission to explore in any case to assess the
environment in a given system to design (if possible) an optimized braking strategy.”
Basically they have no idea how you might even in principle go about braking the thing so until they figure that out they have at an outside best imagined a very high velocity interplanetary/interstellar bullet. Experience with climate pseudoscience has naturally enough made me a little gun-shy of statements like “much more work and simulation is needed”. I could of course say the same of FTL space travel and sit around for decades making computer sims on huge fat grant awards. Speaking of which I believe NASA has mercifully at least defunded research into Alcubierre FTL warp drives owing to the current unavailability of the required negative energy density exotic matter. Can’t even bear to look if they’re still funding space elevator research.
Sorry about the carriage returns – hadn’t realised.
As long as the teleport budget is still good.
Beware of Motis.
But, but, but, the Saucers have already solved this problem (and beyond), the government just needs to release the secret propulsion systems for commercial use.
No idea yet. So they should just scrap the concept? Whatever happened to “While the difficult takes time, the impossible just takes a little longer.”
/Mr Lynn
Trouble is that’s precisely the problem right there. It isn’t even a concept to scrap. There is no concept of how they might brake the thing. When someone comes up with a workable concept then it’s game on again. Meanwhile I appreciate the sentiment but “While the difficult takes time, the impossible just takes a little longer.” is a lovely glib phrase but best applied to poytailed and horn-rimmed advertising executives tackling particularly thorny Venn diagrams. I’m afraid in engineering the impossible usually just takes a little infinity.
That would depend on the “device” that was sent, small has be recon only, but large means Atomic power. mass and maneuverability, so depending on the Solar System you could use all of those that have been mentioned, not just one of them, plus Solar and Planetary braking. I am not sure how many passes would be required to bring down the speed.
But the first item would be a very large nanotec Solar Wind sail and I mean huge, maybe 100Km across. It is what the Atomic power and mass would be used for the whole time they were going there.
All we get from modern science is doom, gloom, everything is against us and how we CAN’T do things rather than how we COULD do things, this paper makes refreshing change even if it is only half a concept.
I know one thing with your attitude Atomic Energy would never have been invented, after all how could anyone conceive of “Splitting an Atom” and releasing it’s energy.
Well as to your first paragraph I think perhaps the team would have mentioned it if they had a practical braking solution in mind. Second thing is I’m not sure you’re quite getting to grips with these relativistic velocities. For the smallest craft they’re looking at around 270 million km/hour and for the largest craft about 4 million km/hour and I don’t think second passes through the system are any kind of reality unless you can come up with a scheme for the required enormous braking. If you can then the people in the OP article would very much like to speak with you I feel confident in asserting.
I know, I really p1ss people off with the old doom and gloom! Thing is though that is how I think science should be done. If someone, or even I, come up with a novel concept then it is everyone’s including the proposer’s, duty to do their utmost nest to knock it down. Only when no one can does it begin to look exciting. False confidence in an effort to look enthusiastic is what makes me gloomy because then everything gets reduced to children playing in a sand pit. Being critical is not the same as being negative. I too find it interesting that they perhaps now have the laser tech down to a state where they can propose this but that doesn’t mean I’m going to go all doe-eyed and conveniently forget about the problems at the other end.
As to your final paragraph – I couldn’t agree less. Atom smashing became a reality because of the slow build up of experimentally supported physical theory until the point at which it was realised that to do such a thing was within the scope of the science and technology of the day. Had Democritus of Abdera proposed splitting his newly proposed atoms he would rightly have been laughed out of the academy because there was no theoretical or physical framework for attempting any such thing. Things only happen in science when their time has come and all the parts are in place to make them a reality. Maybe one day this interstellar proposal will have it’s day but by the looks of things that isn’t this day.
We used to submit projects for funding and they were judged on their likelihood of success because we have finite resources for these things. We also do blue-sky theoretical research for the sake of knowledge and – after all – who knows what may come out of it. What we don’t do – or rather didn’t used to – was run around like farmyard chickens, hemorrhaging tax payers cash on all manner of highly likely blind alleys. It’s a major component of why science is going horribly wrong and the tree is in dire need of a good shake.
(Spoiler Alert) This has been presented in the professional literature: jettison the outer portion of the laser sail and use it as a reflector to shine the laser light back onto the remaining sail on the spacecraft, thus applying a braking thrust. The sail outer portion gets accelerated farther along, but it serves the purpose of slowing down the spacecraft.
Oh lordy if only those guys had known about that suggestion! Email them quick and you’ll be project director before you can say “I haven’t thought this through yet”. But seriously, if you read the article they are talking about acceleration phases lasting minutes after which it’s a free coast to destination. You aren’t suggesting they can target a 1 m sail with a laser from parsec distances – are you? I know that’s how the Moties did it in The Mote in God’s Eye but that was sc-fi for entertainment purposes.
In “Encounter with Tiber,” a SF book by Buzz Aldrin (1996), the Tiberian ship used lasers pointed at its solar sail for propulsion. This was considered “hard” SF. I give it extra credence when Buzz’s name is attached to it.
A friend (to whom I sent the link to the paper) reminds me that the late Gerard K. O’Neill (The High Frontier: Human Colonies in Space [1976], founder of the Space Studies Institute at Princeton) proposed using solar satellites to power light energy to a ship with a sail.
/Mr Lynn
The idea of interplanetary travel by light was mentioned by Jules Verne in From the Earth to the Moon.
Solar radiation pressure on earth, 1361 W/m2 at 1 AU, is 9.08 µN/m2 or 0.0013 oz.in.
There is no ‘mars in 30 minutes’ from radiation pressure.
The pressure is infinitesimal and requires lots of time to achieve any acceleration that can be measured.
Colossal lasers that could produce any pressure you could feel are unavailable to the mortal man.
The idea of a solar sail is one thing- the sun is already there and radiates in all directions so it’s stationary.
Laser powered light surfing is not remotely plausible to me.
Not sure what this all has to do with climate science except some very loose argument about better use of the money which Eric does in one small sentence. I am not sure people would however accept having a raft of tax and legal frameworks is necessary for what is essentially a science funding problem. I have a racehorse system that I am sure would benefit from more funding as well if we are going down this argument.
Now had Eric gone the path that would could fire all the politicians and climate scientists into space, I might have seen a more direct link but probably not a newsworthy article.
It does not need to have anything to do with Climate at all because AW used to have a different heading to this web site. Basically anything to do with Science.
The heading used to be, “Commentary on puzzling things in life, nature, science, weather, climate change, technology, and recent news by Anthony Watts.”
Maybe when the Climate Wars have been won (by the good guys, of course), AW will go back to that broad charter.
/Mr Lynn
IMHO this is one of the best ways to address Climate Change…its Opportunity Cost. We are wasting tremendous resources on nonsense, while more important research goes unfunded. NASA doesn’t even have a replacement system for the Shuttle, and they are wasting their money on climate research.
In addition to the SF novel “Roche world”, Robert Forward prepared a government study for the USAF about 30 years ago (which I had a copy) detailing how we could build a micro wave powered probe that could do the .25c flyby. ( Starwisp ). Because the sail is an array of wires (prepared by printing the wired array on plastic and then letting the plastic evaporate in space), you also have the power from a rectenna for the flyby.
For larger payloads there is the possibility of using the same microwave that launched the bird to do the deceleration by physically altering the sail with an annulus that receives the beam and then reflects it off the inner sail to stop at the destination.
We now have studies showing that we can use microwaves to accelerate a space craft that is deployed at 30,000 feet to orbital velocity while the craft is within the beam (roughly 150 degree arc) . The economics are favourable at roughly our current launch rates. Something that the laser concepts do not achieve. (with a massive computer crash I lost the citation – but it a brief mention within the last couple months on Jerry Pournelle’s site)
There is an outfit called “Escape Dynamics” (look it up) who purport to be able to do this. I wouldn’t hold my breath. These are weapon-class radiation beams and I wouldn’t want to be at the catcher’s mitt.
What are the safety levels of serious power transmission, say a thousand horsepower (~1 MW)? Safest is by rotating shaft (think ocean liner propeller). Next safest is by electrical cable–but don’t touch! After that, if we use photons, we have the very definition of a beam weapon. Not safe at all. It can cut through metal like a blowtorch through cheese.
Let’s just work out how and find a way to send probes to other planets fast. if it is possible it can be done. how is all that troublesome CO2 doing these days? if they can adjust polar ice data and temperature data, maybe they can adjust the CO2 data.
What good would it do to send one. Unless it’s coming back, there’s no way to retrieve any information from the destination.
Obviously you could send another laser accelerator to the destination and have a two way transport system.
Real space travel requires nuclear rockets with at least 3,000,000 times more energy per kg of fuel than chemical reactions can supply. Even with nuclear rockets it will be necessary to collect fuel in transit as proposed by another NASA scientist long ago:
https://diggingintheclay.wordpress.com/2013/06/17/bussard-revisited/
Real space travel requires energy, explosion drives are not an advantage…
I beg your pardon? You are perhaps under the misapprehension that nuclear devices are deficient at producing energy? You haven’t read about the Orion system concept? Check out “Project Daedalus.”