Server Sky: lots of very thin computer satellites

What makes this more economical than running computation on the ground? The only benefit I saw that looks like a benefit is that the cooling is done by black-body radiation, but cooling is a mostly solved problem, right? (I expect it will take more energy to put into orbit than the solar panels will accumulate over their lifetime.)

According to the wiki, the most likely technical show-stopper (which makes sense given the fact that m288 is outside of the inner Van Allen belt) is radiation damage. Proposed fixes include periodic annealing (heating the circuit with a heating element) to repair the damage, and the use of radiation-resistant materials for circuitry.

What about memory? Bits being flipped by cosmic radiation is an issue on Earth; I imagine it must be more significant in space, and annealing won't fix that.

As well, periodic annealing eventually results in your circuit no longer being a circuit, as the wires and capacitors have diffused until there's a short. You might be able to build these with a large enough heat budget that you can get a reasonable number of reheats out of it, but the lifespan is going to be fairly short.

On the surface, this sounds to me like a "Space, because space" project. What are the specific benefits to having our servers in orbit as opposed to on Earth?

Popular science has nothing to do with rationality.

This would probably be sufficiently relevant for Discussion, but strikes me as not being so relevant to main (per Oscar_Cunningham below).

The Lofstrom Loop might be hamstrung by the problem of The Political Economy of Very Large Space Projects. http://www.jetpress.org/volume4/space.htm

Prototyping ServerSky is quite the opposite, however: it's going to become much easier. And if prototyping it shows a clear-cut business case, the decision to launch ServerSky becomes only net-present-value computation, not a problem of political economy. If the Lofstrom Loop proves to be the most cost-effective way to scale ServerSky (and maintain it), it'll just happen.

Here's how I think prototyping ServerSky could become easier: Zac Montgomery at Cornell announced a Kickstarter project last year called KickSat: a CubeSat that sprays chipsats (Sprites). He met his funding target quite handily -- in fact surpassed it by a fairly wide margin. I think KickSat will be launched within the next year or so, courtesy of NASA's ELaNa program.

http://brad.denby.me/starblog/2012/02/

Zac's current emphasis is on proof-of-concept: he wants to just get a launch, and show that ground communication with customized chipsats can be established. The demonstration effect might be quite dramatic. With luck, it could become a global R&D phenomenon roughly paralleling the "mainstreaming" of VLSI design in EECS departments, as inspired by Carver Mead and Lynn Conway, back in the late 70s and early 80s.

Zac's a mere grad student, of course. But the Cornell prof who was leading up his group, Mason Peck (himself a pioneer of the chipsat concept), has since moved into NASA as Chief Technologist, replacing Bobby Braun. So I expect to see significant ferment on the chipsat front. Testing the ServerSky concept any time soon (soon enough to reduce terrestrial energy consumption, anyway) will probably depend on global, massively parallel concurrent engineering and testing of real hardware under real space conditions. I think the financial barrier to such an effort is about to drop to a point where even engineering students in the developing world can consider participation in projects that actually go to orbit. Out of such a milieu, the chance that some very useful innovation arises as an unintended consequence seems high enough to make the effort worthwhile, regardless of whether ServerSky itself hits a showstopper. The Mead-Conway design movement had many flaws, but the first RISC on a chip was one of its early successes; if I'm not mistaken, the ARM chip in your smartphone has a heritage tracing back to an ISI multi-project chip design at Carver Mead's home university, Cal Tech.

I've written on the subject of whether there's anything like a Moore's Law for space launch. I don't think there is one -- launch is governed more by something like Moore's Second Law (the cost of fab lines keeps growing fast), only with a much bigger problem of establishing the Killer App for commercialization.

http://www.thespacereview.com/article/180/1

But I think Moore's Law can still be a driver for space development. New products and services made possible by VLSI scaling (both on spacecraft and on Earth) could result in higher launch rates, which could improve the economies of scale in launcher production and launch operations, and maybe eventually trigger funding in radical space launch technologies -- maybe even Launch Loop, among other ideas. ServerSky is one scenario for "new class of commercial space value propositions". I consider it plausible, at least, if not yet probable.

There is something that feels "wrong" for me in this proposal, it's that it doesn't account for Moore's law. Sending objects to space is expensive (even with a launch loop or a space elevator, it would still be expensive, even if much less than with traditional rockets), so you can't renew the "server sky" every few years. But with Moore's law, computers a few years ahead are much more powerful than the computers of now. Launch "server sky" now, and with Moore's law, in 10 years, we can make servers 32 times faster... but we can't change the ones in orbit.

Other problem is the ping : with a distance of 12789 km, you get at best a ping 85ms, assuming no other delay and that the nearest satellite can answer you directly, which will rule out many possible usages.

Why not build data centers around Earth so that there is always solar power available to some of them (and you perhaps get to use the waste heat for something useful like heating homes), and then make the data centers available everywhere on Earth via satellites or something?

For the communications problem, the idea is to use three dimensional phased arrays of thinsats -- basically a bunch of satellites in a large block working in unison to generate a specific signal, behaving as if they were a much larger antenna. This is tricky and requires precision timing and exact distance information. The array's physical configuration will need to be randomized (or perhaps arranged according to an optimized pattern) in order to prevent grating lobes, a problem with interference patterns that is common with phased arrays. They would link with GPS and each other by radio on multiple bands to achieve "micron-precision thinsat location and orientation within the array".

Sounds like a good application for that vortex radio thing that basically only works in freespace.

The biggest is solar flares and coronal ejections. Not your normal day to day solar winds and stuff, but honking great gouts of energy and/or coronal mass that are flung out.

Another is comms. How many people would use each server? Really? What's the bandwidth divided by users? From the ground going up you either need a well aimed dish or a honking lot of power (or a shitload of antenna topside)

Third is Putting lots of these up isn't a wonderful idea as they will obsolete quickly and need to be replaced. You then have the choice to de-orbit them (wasteful) or leave them up there (danger to navigation).

Fourth, fifth and sixth are security, security and security. How do you apply a security patch to something Up There. Yes, it can be done, but what happens if you Brick It. Back to more engineering and more redundancy and etc. Up goes the cost, up goes the size, down goes the payback. How do you prevent eavesdropping on your communications with it? And with it's communication with you? Encryption? that's either more CPU cost, or more payload to use special processors. How do you protect it from deliberate interference from various organisations that wish to compromise it. etc. etc.

While the lure of "free" energy (or more accurately low cost, reliable energy) is compelling, there's a LOT of ways to get many of those benefits terrestrially. The notion of something like this "reducing poverty" is silly. While there is a lot that processing power can do to reduce poverty, access to raw computing resources ISN'T one of them. You'd be better off deploying something like wifi to GSM connections and building effective mesh network protocols. A for various kinds of research there's plenty of unused power here on this planet. See this: https://flowcharts.llnl.gov/content/energy/energy_archive/energy_flow_2010/LLNLUSEnergy2010.png If you really want to solve a useful problem in this area turning that "rejected energy" into CPU cycles. You've got about 26 Quads of waisted energy JUST from electrical distribution.

That's a metric buttload of entropy that could be put to work solving problems if we could figure out how to get to it. CPU cycles that are close, easily upgradeable, easily defendable, easily recoverable when they die or get obsolesced.

(I have this pet notion that landfills are GOOD places to put stuff we can't use right now, because some day some smart bloke is going to figure out how to use nanotech of some kind to (diamond age style) sort the component bits right out and we'll KNOW where all the high density sources are because we'll have been dumping our old crud in there for a hundred years. Now if we can just keep the crap out of our ground water....)

Overall it can be done, and if you want to deliver compute resources to station owners or Aboriginal Communities in the outback, or nomadic tribes in the desert regions of the world it might be cost effective. But those folks would need a local computer and network to access it, so why not just give them a slightly beefier lapdog and use some sort of distributed compute engine?

I have a tendancy to agree with Mr. Gerard and Mr. Cunningham on this though--while it's an interesting technical exercise and I (clearly) don't mind talking about it, it's not the sort of thing I come here for.