Unmanned Mission to Alpha Centauri, A study of an unmanned mission to the Alpha Centauri system Options

[hendric]

Are present-day artificial intelligence systems up to that level?

I think the issue with AI's is a bit of a non-problem. We regularly update software in-flight, why not with this probe? Say you need to start doing your planning 5 years before arrival, and it takes about 10 years to get your SW to the spacecraft, then your spacecraft can run an AI designed up to 85 years in the future to detect,plan, etc for the landing. Just be sure to launch with a seriously over powerful CPU (well, a couple anyways for backups etc obviously) and a ridiculous amount of extra memory.

Plus, the scientists planning the launch will already know the inclination of the system, right? Instead of aiming for the center of the star, the aimpoint could initally be targeting the habitable zone on the side moving away from Earth. Of course, you'd have to aim for where the system will be in the future, since it would move quite a bit in those 100 years.

Given a sufficiently large telescope, the algorithm for choosing which planets to visit should be fairly simple, right? If there is planet with oxygen in the atmosphere, go there. If not, if a planet has liquid water, go there. If not, if a planet has between .2 and 5 Earth masses, go there. If not, if there is a planet within the habitable zone, go there. If not, attempt to flyby as many of the planets as possible. This would miss Titan, but catch Earth, Venus, and Mars.

With knowledge of a Jovian class planet, would it be possible to plan slingshots through to other planets? That might be too dangerous if they have moon systems similar to ours...Or radiation environments...

Anyways, the AI issue should be easily tractable. The bigger issue is how much mass you expect to send. At a minimum you'd need a nuclear reactor powered spacecraft of some sort, a large telescope for planning the visit, and a giant radio antenna for communicating back home (or maybe a laser comms). And redundant on top of redundant systems. Maybe 100+ kilo kg? (10x Hubble)

This all raises an interesting question: If someone sent a similar probe through our system, would we be able to detect it? Or would it zip by completely unnoticed? If the homeworld is in constant communications, we might see the beam once the spacecraft and sun are sufficiently aligned. But most likely, once the software is updated, the homeworld will be listening for any results instead of transmitting...I think we probably wouldn't notice an interstellar probe, unless it is of the giant-RAMA-spaceship type...

[jasedm]

And once all that were achieved, the hope would be that none of the instruments would go into 'safe' mode during any putative flyby.....

[ugordan]

With knowledge of a Jovian class planet, would it be possible to plan slingshots through to other planets?

Hell, if you have enough capability to accelerate to 5 or 10 % of light speed and then brake at the end, you don't need slingshots. If you don't slow down on the other hand, there's no planet that's going to bend that trajectory (more like a straight line) anyway. Even the star itself would have trouble affecting something going some 50 times its surface escape velocity.

[JRehling]

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[JRehling]

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[ilbasso]

I think the issue with AI's is a bit of a non-problem. We regularly update software in-flight, why not with this probe? Say you need to start doing your planning 5 years before arrival, and it takes about 10 years to get your SW to the spacecraft, then your spacecraft can run an AI designed up to 85 years in the future to detect,plan, etc for the landing. Just be sure to launch with a seriously over powerful CPU (well, a couple anyways for backups etc obviously) and a ridiculous amount of extra memory.

What kind of AI did our computers have or software did they run 85 years ago? Ahhh.....

This is not a trivial issue, as many of our esteemed UMSF members find as they try to deal with data tapes from the 1960's in weird formats for tape readers that no longer exist. Is our attention span good enough to maintain working knowledge of software for a 100 year long mission?

Although, if Ray Kurzweil is correct, then humankind will have reached "The Singularity" by about 2050 and our intelligence will start spreading through the cosmos at the speed of light anyway. So maybe our minds will already be at Alpha Centauri by the time the probe arrives!

[Stephen]

I think the issue with AI's is a bit of a non-problem. We regularly update software in-flight, why not with this probe? Say you need to start doing your planning 5 years before arrival, and it takes about 10 years to get your SW to the spacecraft, then your spacecraft can run an AI designed up to 85 years in the future to detect,plan, etc for the landing. Just be sure to launch with a seriously over powerful CPU (well, a couple anyways for backups etc obviously) and a ridiculous amount of extra memory.

1) What constitutes a "seriously over powerful CPU" and a "ridiculous amount of extra memory"?

Think back to the computing hardware that is currently flying in the Voyagers and you will see how that is not a serious proposition! What would have seemed like a "seriously over powerful CPU" and a "ridiculous amount of extra memory" back in the 1970s is now a mere drop in the proverbial bucket required by much of the software now running on the computing hardware of 2008, let alone the kind likely to be available in the 2060s (1970s + 85 years...), even granted that much of that power in current software tends to be used to display increasingly sophisticated graphical GUIs.

2) I doubt a single CPU, no matter how "seriously over powerful", will be able to run an AI. The human brain seems to make massive use of parallel processing to do the same job, so I suspect (just MHO) the hardware required to run an intelligence of an artificial kind will probably need to do the same as well. The upside: the probe's designers will not necessarily need to include "seriously over powerful" CPUs. Less sorts would probably suffice. The downside: they may well, however, require a very large number of such CPUs, which in turn may tax the power requirements of the probe (amongst other things).

3) As for updating software in flight, sure it's done now although I doubt if anyone's done what you seem to be contemplating: adding the AI **after** launch rather than as before (as part of the original design).

I am however wondering though what the data rate would be for the probe at a distance of 2 or 3 light years from Earth and the size of the update. I notice the Project Longshot paper says: "A laser with an input power of 250 kilowatts would allow for a data rate of 1000 bits per second at maximum range." If we take that as our starting point, then assuming 8 bits per byte (and ignoring the issue of other bits like parity bits etc consumed in the transfer), that equates to about 125 bytes/second, 450,000 bytes per hour, or 10.8 megabytes per day. A software update of about 1 gigabyte would therefore take about 100 days to upload.

Of course this would pale beside the timespan required if the probe, having received the update, then had to verify the uploaded software with Earth (to ensure it was received correctly). If the probe by then was (say) 3 light years out it would be six years (+ another 100 days) after Earth uploaded the last byte that the first of the data to be verified came back. Then a further 3 years before the "OK to proceed" signal could be sent.

In other words, a single 1 gb update could take over a decade to accomplish. (3 years + 100 days to upload update, 3 years +100 days to verify, 3 years to send "OK to proceed".)

Even if the verify were not needed (because the uploaded data was self-verifying) the time involved would not be that much shorter unless the probe did not require Earth's approval to implement the update.

(Of course all of the above assumes that everything uploaded correctly and did not have to be re-sent!)

Given a sufficiently large telescope, the algorithm for choosing which planets to visit should be fairly simple, right?

Are artificial intelligence algorithms "fairly simple"?

With knowledge of a Jovian class planet, would it be possible to plan slingshots through to other planets? That might be too dangerous if they have moon systems similar to ours...Or radiation environments...

Not to mention time consuming. I seem to remember it taking an awful long time for Galileo, Cassini, et al to get around using only gravitation slingshots.

Besides, who will be planning such slingshots? The experts back on Earth or the AI on the probe?

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Stephen

[Stephen]

You should be able to figure out from very far away that Titan is a hell of a lot more promising than Rhea.

This is hindsight talking. Up until Voyager arrived our own Titan was certainly a prime target, however nobody realised that Titan was completely swathed in clouds. Had that been recognised would NASA have still sent Voyager 1 on a trajectory that got it nicely close to Titan but also denied it the opportunity of proceeding on to Uranus and Neptune like Voyager 2 or would it have sent on one that retained the Uranus/Neptune option?

A probe not equipped, or at least ill-equipped, to peer beneath the clouds of Titan (or a Venus for that matter) may well decide that lots of snaps of Rhea's geology would provide a richer data set than lots of snaps of Titan's clouds, especially if the Rhea trajectory also allowed it to proceed on other targets whereas the Titan one did not.

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Stephen

[ugordan]

Had that been recognised would NASA have still sent Voyager 1 on a trajectory that got it nicely close to Titan but also denied it the opportunity of proceeding on to Uranus and Neptune like Voyager 2 or would it have sent on one that retained the Uranus/Neptune option?

Yes, they would have. The information gathered by Voyager 1 was still crucial (in particular the radio occultation) in determining the radius, temperature and pressure profiles of the atmosphere and basically paved the way for Huygens and established a model for Titan's possible surface conditions, which holds up pretty well even now. Had Voyager 1 failed immediately before the Titan flyby (and thus already having provided a view of the global haze shroud), NASA would still have retargeted Voyager 2 at Titan. This alone is sufficient proof that NASA realized Titan was a high priority target even from distant groundbased observations, high enough to forgo possible Uranus/Neptune encounters if necessary. They would have thrown even the kitchen sink at Titan if they needed to to get this data.

Also, hindsight talking or not, if you're unable to determine from very far away if a world is interesting, you can write off your close approach ideas whether you have Godlike AI or not. There simply will not be enough propellant to retarget the craft once you get close enough to actually resolve the body. As JRehling said, this constrains the parameter space so much that even humans wouldn't be able to do a much better job at picking targets based on a couple of spectra alone. You're stuck with distant data to work with.

[djellison]

3) As for updating software in flight, sure it's done now although I doubt if anyone's done what you seem to be contemplating: adding the AI **after** launch rather than as before (as part of the original design).

Whilst personally, I consider this entire thread to be more about science fiction than anything else (check the forum rules for what that means) - I will pick you up here.

The MER's have had several significant flight software updates that have given them abilities not even considered before launch. It depends where you definition of AI lies - but go-and-touch, automated DD/Cloud watching, D-star etc, are all abilities that were developed long after landing and uplinked to a vehicle designed, built and launched without those abilities in mind. It's not unreasonable to say that the MER's that drove in their primary mission lacked intelligence (but not autonomy), and the MER's today have both an element of intelligence and autonomy.

[hendric]

1) What constitutes a "seriously over powerful CPU" and a "ridiculous amount of extra memory"?

Are we talking about a probe being launched in the 70's or today? I was assuming today. If it was still in the 70's, then the hardest part of the AI will not be determining which objects to visit, which is trivially simple, but detecting objects at all. But, on the other hand, any AI, primitive or not, would be given a vast amount of time to make a decision, with constantly improving data being input into the process. After all, the decision does not need to be made real-time. The data could be captured in a month, and then a year spent processing it. Even 1970's era equipment could give you an answer in that amount of time.

2) I doubt a single CPU, no matter how "seriously over powerful", will be able to run an AI.

Modern CPUs are vastly overpowered for what the probe would need. It is possible to purchase CPUs with 8+ cores on them. I think an AI in the terms of what is necessary (image taking, planetary object recognition, intensive imaging of objects, determining score, selecting primary targets, adjusting course) wouldn't really need to be much, given the relatively small sample size (what's the most planetary objects we'd expect? 30?) and the large amounts of time to make a decision. (months - years)

3) As for updating software in flight, sure it's done now although I doubt if anyone's done what you seem to be contemplating: adding the AI **after** launch rather than as before (as part of the original design).

As others have said, it's done all the time now. Many probes are sent out with the flight software updated en route. (I seem to recall a spacecraft being sent out without any encounter software, just cruise software. Was that the MER's? I forget!) SW is the hard part of any design. Once the HW is proven and in the air, all you've got is time to refine SW.

A software update of about 1 gigabyte would therefore take about 100 days to upload.
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In other words, a single 1 gb update could take over a decade to accomplish. (3 years + 100 days to upload update, 3 years +100 days to verify, 3 years to send "OK to proceed".)

You would never implement an update like this. You would just send your update continuously. I doubt the update would be 1GB, but even with that, you can send 3 1/2 copies of that data in one year, and need not worry about validation, since the probe would validate the data as it received it through CRCs, much like a BitTorrent. With modern error detection and correction codes 3.5x the data gives you ridiculous amounts of redundancy. Data transmission is a very well-studied field; any reception problems would be very temporal, and many simple algorithms can deal with that. Look at how well cellphones send and receive data through ridiculously difficult conditions: moving receiver, multipath, shared spectrum, etc.

That's assuming 1970's technology of course. With modern technology, I wouldn't be surprised if there was a 10 to 100x improvement just due to the ECC codes.

Are artificial intelligence algorithms "fairly simple"?
Not to mention time consuming. I seem to remember it taking an awful long time for Galileo, Cassini, et al to get around using only gravitation slingshots.
Besides, who will be planning such slingshots? The experts back on Earth or the AI on the probe?
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Stephen

Well no AIs are not simple, but AI in term of predicting the course of a hurricane or identifying a person on a photo is orders of magnitude more complicated than looking at 30 planetary objects and deciding the one or two to visit based on a couple of parameters, and then plotting a course to them.

[JRehling]

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[JRehling]

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[brellis]

... if Ray Kurzweil is correct, then humankind will have reached "The Singularity" by about 2050 and our intelligence will start spreading through the cosmos at the speed of light anyway. So maybe our minds will already be at Alpha Centauri by the time the probe arrives!

I play on a 25 year old Kurweil keyboard; does that get me a ticket on "The Singularity"?

How about a nano-level self-generating type of craft that is committed to staying in touch with us? We could be testing that technology here in our own SS some time soon.
Recent articles about solar sail craft that could be precursors to interstellar craft -- June, 2008 Planetary Society Article, another article