Spaceward ho!

April 12, 2016 10:45 AM

Stephen Hawking & Russian Billionaire want to Build an Interstellar Starship Nanocrafts!
posted by lips (62 comments total)

An auspicious day to announce this! Today is the 55th anniversary of the day Yuri Gagarin completed the first human spaceflight in Vostok 1.
posted by griphus at 10:52 AM on April 12, 2016 [6 favorites]

This concept has been around for literally decades with not much in the way of actual results. Wake me when they actually get one of these out of the atmosphere. Or even as high up as the jet stream.
posted by tobascodagama at 10:56 AM on April 12, 2016

Sarcastic Rover on Twitter nailed it: Russian Billionaire and wheelchair-bound genius want to do something innocent BUT FIRST they need a giant laser? NICE TRY BOND VILLAINS!

I mean, the endeavour sounds cool but .. I cannot get rid of that image now.
posted by kariebookish at 11:00 AM on April 12, 2016 [24 favorites]

if our first interstellar spaceships aren't modeled after WW2-era battleships and bristling with turbolasers, then what the fuck is the point of interstellar travel even
posted by prize bull octorok at 11:00 AM on April 12, 2016 [27 favorites]

Ok, just assume you could use a ground based laser to accelerate a nanoscale craft to something like 2/10 C, which has obviously never been tried. The biggest problem would be transmitting any data collected back to Earth. You can't carry a transitional radio antenna on a craft that small, and in any case it would be traveling faster than any control signal from Earth, so you'd only have one way communication. So you'd have to first build the first operational laser communication system, then figure out how to get a power source on board the tiny craft sufficient to power the laser comm system from 4LY out.

Cool idea, massive engineering problems. But I like seeing billionaires throw money at hard problems rather than hoard 300 year old scotch in endangered tiger bladders.
posted by T.D. Strange at 11:08 AM on April 12, 2016 [11 favorites]

Centauri Dreams: Breakthrough Starshot: Mission to Alpha Centauri

At the very least, we can expect the research behind this project to spin off numerous useful technologies, all of which should be applicable not only to star missions but to in-system exploration, along with, potentially, a kilometer-scale beamer that can double as a large telescope for astronomical observations. And while I doubt we can look at interstellar missions within the next few decades (I am open to being convinced otherwise), I believe that the timing for a fast flyby of Alpha Centauri will be considerably advanced by this work.

posted by audi alteram partem at 11:09 AM on April 12, 2016 [1 favorite]

But I like seeing billionaires throw money at hard problems rather than hoard 300 year old scotch in endangered tiger bladders.

Have you tried it, though? It's grrrrrreat
posted by clockzero at 11:10 AM on April 12, 2016 [16 favorites]

Dear World,
STOP MAKING ME COMPARE EVERYTHING TO "THE THREE-BODY PROBLEM"!!!!

So yeah, this just like "The Three-Body Problem," but in reverse.
posted by NoMich at 11:16 AM on April 12, 2016 [3 favorites]

Okay so let's assume we have two perfectly spherical endangered tiger bladders filled with 300-year-old scotch. One remains on earth while the other is accelerated to relativistic speeds by a hypothetical macro-scale light sail vehicle. How soon can we get drunk on Alpha Centauri?
posted by griphus at 11:18 AM on April 12, 2016 [9 favorites]

"Breakthrough Starshot"? Seriously?

That's the crappiest name for an interstellar transport project I've ever heard.

It's also the crappiest name for anything else.

Clearly, the project should be called Starshippy McStarshipface.
posted by crazylegs at 11:19 AM on April 12, 2016 [4 favorites]

How soon can we get drunk on Alpha Centauri?

Just because you assumed the cows to be spheres does not mean the assumption is safe for the bladders.
posted by RolandOfEld at 11:19 AM on April 12, 2016 [1 favorite]

I feel like Stephen Hawking reached out to Yuri Milner like Kanye tweeted Mark Zuckerberg, but Stephen, being more tactful, chose to text Yuri.

"Yuri Milner invest 1 billion dollars into Stephen Hawking ideas"
"OK"

At least, that's how I like to imagine this all starting.
posted by filthy light thief at 11:19 AM on April 12, 2016 [8 favorites]

This shows next-level thinking: Hawking is throwing his support behind this effort not because he thinks an interstellar probe weighing a gram will be able to return any data, but because he's worried about aliens conquering the Earth and he wants us to develop ground-based hectogigawatt lasers to defend ourselves.
posted by The Tensor at 11:21 AM on April 12, 2016 [6 favorites]

Here's how we solve the communication problem: once the nanobots get to Alpha Centauri, they swoop around and do their stuff, then assemble into a giant robot laser array that beams the data back. Then returns to earth and fights Godzilla. Simple!
posted by BitterOldPunk at 11:21 AM on April 12, 2016 [2 favorites]

I wonder what aliens will think when a pile of nanocrafts are catapulted into their backyard by another life form with a giant space laser.
posted by dazed_one at 11:22 AM on April 12, 2016 [1 favorite]

Isn't there a Larry Niven story about exactly that?
posted by griphus at 11:23 AM on April 12, 2016

100 jigawatts?! /eyebulge
posted by Esteemed Offendi at 11:30 AM on April 12, 2016

By my rough, back-of-the-envelope calculations (check my numbers physicists), A 1g nanosatellite travelling at 0.2c has a kinetic energy equivalent to roughly 2E12 J, or about 5% of the explosive yield of the bomb used on Hiroshima.
A swarm of those hitting a planet will cause a bit of an interstellar incident, though probably not genocide if that is any consolation.
posted by cardboard at 11:30 AM on April 12, 2016 [2 favorites]

Well, if you gotta spend 100M on something that isn't me, this'll do.
posted by Brandon Blatcher at 11:33 AM on April 12, 2016 [3 favorites]

This is like some kind of real-world fan fiction.
posted by DirtyOldTown at 11:34 AM on April 12, 2016 [2 favorites]

If Hawking didn't direct this Russian oligarch's money, it would be directed to something else.

Ergo, good on you, Dr. Hawking. Keep up the good work.
posted by ocschwar at 11:48 AM on April 12, 2016

Isn't there a Larry Niven story about exactly that?

It's The Mote in God's Eye. It's aged... Very poorly. Was quite a shock to the system After binging on Alastair Reynolds.
posted by Mr.Encyclopedia at 11:50 AM on April 12, 2016 [2 favorites]

Isn't there a Larry Niven story about exactly that?

There's a close parallel to the concept in Accelerando, by (Mefi's own) Charlie Stross. "Router" features "... the spacecraft Field Circus, a Coke-can-sized mass of computronium propelled by a Jupiter-based laser and a lightsail."

But this was for *after* the Singularity. I guess these guys know something we don't ... yet.
posted by RedOrGreen at 12:15 PM on April 12, 2016 [2 favorites]

> I like seeing billionaires throw money at hard problems rather than hoard 300 year old scotch in endangered tiger bladders.

> if you gotta spend 100M on something that isn't me, this'll do.

Yeah, Yuri Milner is throwing $100M at Breakthrough Listen, which is a lifeline for our endangered radio telescopes (at least for the Green Bank telescope; the Arecibo situation is still mired in politics) in this era of declining support from the National Science Foundation. And yet I'm really conflicted about this.

On one hand, I think this is the longest of long shots, but the payoff is so significant that we (humans) must try it. There's no easy way this gets funded by Congress today, so good for YM for making it possible!

On the other hand, these radio telescopes have their time competitively allocated by peer review panels based on their scientific merit, to any astronomer in the world. In spite of its flaws, the process is the most democratic (or meritocratic) we've got. So it feels like cheating when someone can just *buy* time to throw at their favorite problem. Even if it's a problem I'm glad to see addressed, the process leaves me deeply conflicted. What next, a return to the patronage model?
posted by RedOrGreen at 12:24 PM on April 12, 2016 [1 favorite]

If billionaires paid their taxes we could fund universal basic income AND a fleet of spacegoing lasers to accelerate phone-sized probes to ridiculous speeds.

Warm up the Navy, let's go seize the future.
posted by fifteen schnitzengruben is my limit at 12:29 PM on April 12, 2016 [5 favorites]

Cell-phone sized, you say? Maybe the intent is that the phone companies will roll out LTE service to Alpha Centauri by the time the nanoprobes get there.
posted by tobascodagama at 12:38 PM on April 12, 2016

Even if it's a problem I'm glad to see addressed, the process leaves me deeply conflicted. What next, a return to the patronage model?

With the gutting of government support for science, social services, infrastructure, the arts, etc., that seems inevitable. We're coming to rely on the largess of people like Gates and Buffet for necessities, or Milner and Musk for research.

Luckily that's just a bridge step to the future neo-feudalism our descendants will enjoy.
posted by Sangermaine at 1:03 PM on April 12, 2016 [2 favorites]

The odds may be pretty good, but I have no idea: How likely is a 4ly dust-free "lane" in space? Because I imagine you can't really hit anything at all and survive.
posted by maxwelton at 1:06 PM on April 12, 2016 [1 favorite]

Also, did anyone else ever read The Millennial Project: Colonizing the Galaxy in Eight Easy Steps? I read it in middle school but no ever seems to have heard of it. It's full of all kinds of crazy ideas, including a laser launch system like the one proposed except much bigger and built into the side of Mt. Kilimanjaro.
posted by Sangermaine at 1:08 PM on April 12, 2016 [1 favorite]

Wow! I really hope this is solid and not vapor. Sending nanocraft to Alpha Centauri could be the end goal - but like it says in the article, the same technology could do a lot for space science in this solar system. Just building the laser array would be a huge achievement that would definitely push technology forward.

Still...

T.D. Strange: "The biggest problem would be transmitting any data collected back to Earth..."

Exactly! That's a big problem. Is it even achievable with current technology?
posted by Kevin Street at 1:23 PM on April 12, 2016

Focusing some kind of Earth (or near Earth) receiver on a tiny little laser beam that's an enormous distance away seems like a pretty hard problem to crack.
posted by Kevin Street at 1:27 PM on April 12, 2016

Current radio tech could easily communicate with Alpha Centauri, but you do need large radio telescopes at both ends (I've got the link budget somewhere, but can't find it just now). RedOrGreen is a professional RF photon collector, he may have some ideas.

Communicating with a coke-can sized thingy is... more challenging, and bits of physics do get in the way - you can't easily compensate for lack of energy at one end by making the other more sensitive, past a certain point. If the light sail is big enough and shiny enough, perhaps you could wait until you're a decent distance beyond the target star, so you don't get swamped, and then reflect starlight back at the earth and modulate it by changing alignment - think heliograph - and I do quite like the idea of the most advanced ever spaceprobe talking back by a technology known to the Romans and, if we're being posh, Morse code. Perhaps we could do it in conjunction with that cool idea to park a relay satellite out at the focal point where you can use the Sun as a gravitational lens, although even that is way beyond us at the moemnt (it's a LONG way from the Sun - 100+ AU, if I remember correctly).

The other thing that bothers me is that laser beams diverge, and I wonder how much of this idea is based on the notion that we can stop that happening, because as far as I know it ain't gonna happen bar magic.
posted by Devonian at 1:38 PM on April 12, 2016 [6 favorites]

Wow! I really hope this is solid and not vapor.

Here's hoping, but most things you hit with a 100-gigawatt laser aren't.
posted by sfenders at 1:47 PM on April 12, 2016 [2 favorites]

I like your heliograph idea, Devonian! It would be a lot brighter than a tiny onboard laser beam, but there might be a limitation when it comes to bandwidth. If these things are travelling at relativistic speeds they won't be close enough to Alpha Centauri to make observations for long, so the amount of information the little chips can collect and transmit is going to be limited. A heliograph is a physical system (since it relies upon moving cables or whatever attaches the light sail to the chip), so it probably wouldn't be as fast as something solid state like a fluctuating laser. Or maybe not. Who knows at this point! :)

Maybe the solution is to send lots and lots of little nanocraft, like maybe dozens or hundreds at a time. Then there'd be hundreds of little laser beams to focus on, and if they were all sending the same information a computer could filter out the redunancies and errors and patch together a complete copy of the telemetry.
posted by Kevin Street at 1:50 PM on April 12, 2016 [1 favorite]

If one way communication might be doable, but two was is ... difficult, when why bother with two way? If the device can't steer or slow down I fail to see the utility of two way communication. I assume that these devices will do one way communication; screaming out to us, with us needing to be listening very carefully to find it. Program the cameras for a concept of "interesting", have them seek that, and scream out what they find.

Dust: is mentioned here. http://breakthroughinitiatives.org/Challenges/3 - the list a 10% chance of collision with dust particles 1 micron or greater (while noting there isn't a good profile of Alpha Centauri dust).

Realistically this is such a complex undertaking, even potentially getting a blurred image of ... anything from Alpha Centauri would be such a giant success of this. We're not expecting Mars rover, nor Horizons levels data, images and quality. We're expecting to say, "Hey, we just shot something 4.3 light years away, and it got where we intended it to, and we heard it report. And the people who sent this out lived to hear the report! Oh, and here's a blurry image."

... I find this really exciting in a way that's given me a low-level smile since I heard about it.
posted by nobeagle at 1:57 PM on April 12, 2016

Yeah, bandwidth and light density are not in favour of mirrorchipping. But who knows, indeed.

I hope the thing gets called something better. Something like Ballistic Observatory With Intelligent Electronics or Stellar Transit Advanced Reflective Material Accelerated Nanocraft.

Nothing less will do, obvs.

ETA - Nobeagle, talking from us to it is far simpler than the other way. We have tons of power and room for big antenna. It doesn't.
posted by Devonian at 1:59 PM on April 12, 2016 [3 favorites]

> The other thing that bothers me is that laser beams diverge

Or do they? Dun dun dun...

Well, yeah, once you're far enough away, they do. But it turns out that in the near-field regime, they don't, and what counts as "near field" is tunable.

Here is a paper by Guillochon and Loeb - which frankly reads like something they thought up over too many beers, and knowing these people, that's not even unlikely - where they describe a rapid transit system between neighboring planets using microwaves and light sails. The leakage from those rapid transit systems would be detectable as a SETI signal given a fortuitous alignment.

Look at their Figure 1, where they show the beam profile of the laser (or maser) array that powers these light sail craft in this hypothetical rapid transit setup. During the all-important acceleration phase of the spacecraft, the laser signal might not even diverge very much.

(The linked paper is a seriously fun read! You have equation (2) for the total power requirement for an efficient light sail: Power = 1.5 TW * mass in metric tons * acceleration in units of g, so accelerating something ~0.1 ton at 1g would require less power than a Saturn V rocket - but sustained.)
posted by RedOrGreen at 2:06 PM on April 12, 2016 [5 favorites]

> Maybe the solution is to send lots and lots of little nanocraft, like maybe dozens or hundreds at a time.

Mason Peck, formerly NASA's Chief Technologist and currently here at Cornell, is involved with this project. They've thought of this idea.
posted by RedOrGreen at 2:09 PM on April 12, 2016 [1 favorite]

We have tons of power and room for big antenna. It doesn't.

Earth telescopes have difficulty seeing entire planets when they're light years away. A quick search of the web suggests that "a few light years" is the range at which our most powerful radio broadcasts become indistinguishable from background noise. Even if you gave it a 20,000-watt transmitter that weights 0.8 grams, how is it supposed to get a message from Alpha Centauri? They must have some clever tricks in mind?
posted by sfenders at 2:23 PM on April 12, 2016

Devonian; sorry I misread your comment. When you said that communicating with a coke can was more challening, initially I assumed you meant the comparison to be against the coke can signally to us. On reread, it appears that you were comparing it to the previous paragraph of two radio telescopes.

Regardless of communicating back to earth being the more difficult part, I don't see a lot of utility from two way communication with this device given there's already some serious mass/power constraints, lag and general lack of capabilities. Short of two way communication being something intrinsic with the one way transmitter I imagine these devices will be deaf screamers.
posted by nobeagle at 2:25 PM on April 12, 2016 [1 favorite]

If yelling at Alpha Centuri is the goal though, we could do a much better job of it by omitting the spacebulletship part.
posted by rodlymight at 2:46 PM on April 12, 2016 [1 favorite]

When you said that communicating with a coke can was more challening, initially I assumed you meant the comparison to be against the coke can signally to us.

Communicating with coke cans used to be easy, before the doctors changed my prescription.
posted by AdamCSnider at 2:50 PM on April 12, 2016 [5 favorites]

Yeah, there's really no point in talking to it - the round-trip time alone makes it a useless conversation, unless you're planning a secondary mission a la New Horizons where you've got a lot of time in the cruise before you have to make a decision. That's just not on the table.

Similarly, there's really no point in the mission unless you do have comms in the other direction. So it's ironic that we could decide to burn a hole in space and fling enough EM at it so it could hear us, and that would be sorta-feasible with the stuff we can knock together already, but the other way is really, really hard to even approach on paper.

If it wasn't so late, I'd go out and hunt down the numbers on this - it's been thought about for a long time - but this is going to be my personal favourite bit of the project to follow.

RedOrGreen: that is a great paper and tons of fun. Diffraction and near/far field effects do give me a headache, though, the last time I sat down and tried to convince myself I understood them, it didn't end well - ISTR I fell down the wrong rabbit hole and ended up contemplating the question "if accelerated charges emit energy, why don't charges in a gravitational field?" and had to lie down for a bit.
posted by Devonian at 2:57 PM on April 12, 2016

An first I thought this FPP sounded much like Lexx, but I see the craft themselves are tiny after reading the article.
posted by jeffburdges at 3:00 PM on April 12, 2016

Yea, the two way communication problem could be avoided if you fired like 20 of them or something and just hoped that a couple were on target enough to return observations. But it'd be pretty useful to be able to make midcourse corrections, since otherwise you're basically eyeballing it from 4LY, a little bit off and your probe isn't going to make it into the system. But the second part of that problem is the local power issue, you've got enough room on board for a laser communications system the same size as the one you use to entertain your cat. Now scale the output on that enough up to relay useful data home from Alpha Centauri, but don't add any amount of weight.
posted by T.D. Strange at 3:18 PM on April 12, 2016

They appear to be moving in the direction of panspermia.
posted by telstar at 3:24 PM on April 12, 2016

I hope the thing gets called something better.

Interstellar Mission Propelled by Lasers Across the Universe with Super Impressive, Believable, and Logical Expectations
posted by dephlogisticated at 3:47 PM on April 12, 2016 [5 favorites]

did anyone else ever read The Millennial Project: Colonizing the Galaxy in Eight Easy Steps?

Yes, and I was just thinking about it. IIRC step 1 was building floating algae farm settlements in the ocean, so we're not really with the program yet.
posted by RobotVoodooPower at 3:54 PM on April 12, 2016

http://breakthroughinitiatives.org/Challenges/3 discusses many of the problems mentioned in this thread.

Potential collision of nanocraft with planet may be the best web page title I've ever seen.
posted by joeyh at 4:29 PM on April 12, 2016

what counts as "near field" is tunable.

I somehow didn't expect "tunable" to extend to seeing 1W lasers at 4 light years. Apparently they think it possible to catch enough photons to get a signal through. All it takes is the sail somehow transmogrifying itself into a fresnel lense to focus the laser when it wants to transmit. "A kilometer-scale receiving array would intercept 10-14 of the transmitted signal." 10 to 14 what? Photons per laser pulse maybe?
posted by sfenders at 6:49 PM on April 12, 2016

If the probe whips through the Alpha Centauri system at .2c, then it'll get beyond it and to the star's gravitational focal point within about two weeks.

Communicating between stellar focal points is stupid-easy.

If we put a receiver at our sun's focal point (about three light days away), the AC probe and the receiver can theoretically talk to each other with a transmission power of 0.1 milliwatts. About 1/50 of the power of the laser you use to entertain your cat.
posted by Hatashran at 7:13 PM on April 12, 2016 [4 favorites]

MetaFilter: probably not genocide if that is any consolation.
posted by danhon at 7:14 PM on April 12, 2016

What if we fired a series of probes at relative intervals and had them broadcast and repeat codes down the line? The individual signals wouldn't have to be that strong then, though it would be a bigger commitment of resources.

There's a bit in one of Alastair Reynolds' books—Blue Remembered Earth, I think— where they use a massive space telescope with multiple stations to achieve resolution enough to see features on planets orbiting different suns. Might be slightly more feasible than a ragtag fleet of microprobes, but not nearly as cool.
posted by fifteen schnitzengruben is my limit at 7:23 PM on April 12, 2016

The thing I like is where they bring the aliens a cannoli.
posted by newdaddy at 9:30 PM on April 12, 2016

Big scary laser.

Let's hope those illuminated by it don't have something bigger and scarier to shine back in our direction.
posted by hank at 10:31 PM on April 12, 2016

Some details revealed!

Yuri Milner speaks to the Atlantic Magazine about Starshot.
posted by Kevin Street at 11:04 PM on April 12, 2016

Wise to worry about the superweapon aspect - a ground-based laser might not be able to fry cities, but it sure could cook a few milsats.

And I note the Atlantic article doesn't touch on comms (and also speaks blithely about the probe 'entering orbit'. Which, er, no, it goes wheeeeeeee-snap-snap-wheeeeeeeee)
posted by Devonian at 3:58 AM on April 13, 2016 [1 favorite]

I wonder what aliens will think when a pile of nanocrafts are catapulted into their backyard by another life form with a giant space laser.

I wouldn't worry too much about it.
posted by AndrewInDC at 9:17 AM on April 13, 2016

sfenders, there's some confusion here, and I'm happy to clarify if you point me to the exact spot you're looking at. Meanwhile, I suspect that:

> "A kilometer-scale receiving array would intercept 10-14 of the transmitted signal." 10 to 14 what? Photons per laser pulse maybe?

... this should read as 10^{-14}, or 1 part in 1 followed by 14 zeros. So only 0.000 000 000 000 01 of the laser output power is intercepted by the eavesdropping SETI detector (I think that's what is meant here); most of it is powering the sail.
posted by RedOrGreen at 9:55 AM on April 13, 2016 [1 favorite]

Thanks, 10^{-14} seems possible. Although, sorry for not being more clear, it wasn't the paper you linked I was quoting from, it was the breakthrough thing, under "Sending images". It has in common with Guillochon and Loeb that it's talking about space lasers, Fresnel, and things I don't understand. Anyway on better reading I see you can't actually have near field extend that far without a gigantic lense, even if with one you can have it go to some astronomically significant distances across a solar system.
posted by sfenders at 1:14 PM on April 13, 2016

Oh, a commenter there cleared up another confusing point as well: "for a 4 metre diameter sail the diffraction limited spot size at Earth would be 10,000,000,000 m, not 1000 m as written above. The 10^-14 of the signal being collected by a kilometre sized receiver is right, though."
posted by sfenders at 1:26 PM on April 13, 2016

Breakthrough Discuss: Initial Thoughts

As became evident in the discussion both at the Yuri’s Night party and during the conference at Stanford, no one is taking these problems lightly. The $100 million that Milner has put forward toward Breakthrough Starshot is to be used to dig into these key questions, to stress the concept to the breaking point, identify its weaknesses and learn how to resolve them. Will there be a genuine show-stopper somewhere in this investigation? At this point we can’t know, but we’ll have the research funding now to identify them if they are there. And as we are talking in generational terms, we’ll also identify the trends that may make the improbable possible.

posted by audi alteram partem at 7:11 AM on April 18, 2016