<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div><br>Not sure bitcoin mining is a good demo app. Seems like lots of communication with a master server would be needed to determine if a unique hash had been obtained.</div><div><div><br></div><div>Have you looked at the recent RFP for cubesat?</div><div><a href="http://www.nsf.gov/funding/pgm_summ.jsp?pims_id=503172">http://www.nsf.gov/funding/pgm_summ.jsp?pims_id=503172</a></div><div><br></div><div>Wonder if you could disperse a cloud of micro-servers that would just compute their nearest neighbor distance, or various moments of the cloud of servers. Might be very useful for gravimetric studies. You are probably aware of the growing problems with space debris. I don't think NASA would let you deploy into a useful orbit unless you had a foolproof way of decommissioning the micro-servers.</div><div><br></div><div>-Ed</div><div><br></div></div><div><br><div><div>On Apr 17, 2012, at 5:00 AM, <a href="mailto:server-sky-request@server-sky.com">server-sky-request@server-sky.com</a> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Send Server-sky mailing list submissions to<br><span class="Apple-tab-span" style="white-space:pre"> </span><a href="mailto:server-sky@lists.server-sky.com">server-sky@lists.server-sky.com</a><br><br>To subscribe or unsubscribe via the World Wide Web, visit<br><span class="Apple-tab-span" style="white-space:pre"> </span>http://lists.server-sky.com/mailman/listinfo/server-sky<br>or, via email, send a message with subject or body 'help' to<br><span class="Apple-tab-span" style="white-space:pre"> </span>server-sky-request@lists.server-sky.com<br><br>You can reach the person managing the list at<br><span class="Apple-tab-span" style="white-space:pre"> </span>server-sky-owner@lists.server-sky.com<br><br>When replying, please edit your Subject line so it is more specific<br>than "Re: Contents of Server-sky digest..."<br><br><br>Today's Topics:<br><br> 1. Bitcoin mining (Luke Parrish)<br><br><br>----------------------------------------------------------------------<br><br>Message: 1<br>Date: Mon, 16 Apr 2012 15:51:28 -0700<br>From: Luke Parrish <lsparrish@rationalsites.com><br>Subject: [Server-sky] Bitcoin mining<br>To: server-sky@lists.server-sky.com<br>Message-ID:<br><span class="Apple-tab-span" style="white-space:pre"> </span><CAKSy3=8ucjKxCca_gJBv+2p3Loxvs1iWk5mDzOjmkBuVFsJvgg@mail.gmail.com><br>Content-Type: text/plain; charset="iso-8859-1"<br><br>This is an idea I had recently. For quick ROI, especially on early<br>"prototype" sats that nobody trusts with their valuable data, one could<br>start by mining bitcoin.<br><br>Bitcoin is a digital commodity that behaves like a currency. There are<br>entire startups based around it. If you have bitcoins in your account, you<br>can transfer to someone else's by publishing a transaction that only you<br>can create. To make sure transactions are valid, instead of having a single<br>third party verify them, a peer to peer system is used to allow everyone<br>with a processor to check the transactions, over and over.<br><br>The creator's original goal was for it to employ CPU power so there would<br>be easy entry and everyone could just check a box on their PC for a few<br>starter bitcoins. However since the SHA256 hash was chosen, which is highly<br>parallelizable, use of GPU (graphical processing unit) cards turned out to<br>be massively more cost-effective. Currently the only energy-efficient ways<br>are high end GPU cards and FPGAs, and these are employed by people ranging<br>from hardware hobbyists to sophisticated server farms. Verification is<br>known as "mining" because it rewards verifiers with bitcoins.<br><br>Bitcoins are distributed (at a rate of one block of 50 per 10 minutes, with<br>difficulty automatically adjusted to keep the rate constant), to whoever<br>solves the block (finds a qualifying, i.e. low numbered hash) first. It's<br>like a race. The more computing power the whole network has, the lower the<br>probability of getting a block per unit hashing power -- which translates<br>to joules of energy depending on the hardware. If you can beat everyone<br>else by using a much more efficient system or a cheaper power source, they<br>eventually have to stop because their hardware no longer able to pay for<br>the electricity it uses.<br><br>So on to my speculation: As long as blackbody cooling and cheap solar are<br>sufficient to overcome the disadvantages of launch costs and custom<br>manufacturing, space-based thinsats optimized for bitcoin mining (computing<br>SHA-256 hashes) should be able to outcompete ground-based server farms.<br>Thus miners who want to stay in the mining business will be forced to sell<br>some of their bitcoins for dollars (or borrow against them) and purchase<br>their own space-based thinsat rigs. Eventually, the profits and empirical<br>results obtained from doing this should be useful enough to create more<br>general-purpose thinsats and branch into robust data storage and general<br>computation.<br>-------------- next part --------------<br>An HTML attachment was scrubbed...<br>URL: http://lists.server-sky.com/pipermail/server-sky/attachments/20120416/02cfb617/attachment-0001.html <br><br>------------------------------<br><br>_______________________________________________<br>Server-sky mailing list<br>Server-sky@lists.server-sky.com<br>http://lists.server-sky.com/mailman/listinfo/server-sky<br><br><br>End of Server-sky Digest, Vol 7, Issue 2<br>****************************************<br></div></blockquote></div><br><div>
<br>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br>Edward D. Zaron<br>Research Assistant Professor<br>Department of Civil and Environmental Engineering<br>Portland State University<br>Portland, OR 97207-0751<br>Phone: (503)-725-2435<br>FAX: (503)-725-5950<br><a href="mailto:zaron@cecs.pdx.edu">zaron@cecs.pdx.edu</a><br>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br><br>
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