{{short description|American electrical engineer}} '''Keith Lofstrom''' (born 1953 in [[Portland, Oregon]])<ref name="Alcor">{{cite web |url=https://www.alcor.org/library/alcor-member-profiles/keith-lofstrom/ |title=Alcor Member Profile: Keith Lofstrom |author=Chana Phaedra |date=2012 |website= |publisher=Cryonics |access-date=May 17, 2024 |quote=}}</ref> is an American [[electrical engineer]]. He has a BSEE and MSEE from [[University of California, Berkeley]].<ref>{{Cite thesis | last = Lofstrom | first = Keith | title = Sinusoidal supply Josephson logic | publisher = U.C. Berkeley | type = Master's thesis | year = 1975 | url = https://books.google.com/books?id=2WQMGwAACAAJ&q=sinusoidal.supply.josephson.logic }} </ref> He is more widely known in the [[space advocacy]] community for a ground-based space launcher design, the [[Launch loop|Launch Loop]],<ref>{{cite journal | last = Lofstrom | first = Keith H. | title = The launch loop -- a low cost Earth-to-high orbit launch system - Paper 85-1368 | publisher = 21st AIAA, SAE, ASME, and ASEE, Joint Propulsion Conference | location = Monterey, CA | date = 8–10 July 1985 | url = http://launchloop.com/LaunchLoop?action=AttachFile&do=get&target=launchloop.pdf }} </ref><ref>{{cite news | first = Charles | last = Radley | title = Local inventor says launch loop would greatly reduce cost of space travel | publisher = [[Examiner.com]] | work = Gadgets and Tech: Portland Science Examiner | location = San Francisco | date=September 14, 2009 }} </ref><ref>{{Cite encyclopedia | title = Space Towers | last = Alexander Bolonkin | author-link = :ru:Болонкин, Александр Александрович | chapter = 8 | editor1-first = Viorel | editor1-last = Badescu | editor2-first = Richard Brook | editor2-last = Cathcart | editor3-first = Roelof D. | editor3-last = Schuiling | encyclopedia = Macro-engineering: a challenge for the future | pages = 146–7 | publisher = [[Springer Science+Business Media|Springer]] | year = 2006 | isbn = 1-4020-3739-2 }} </ref> for which he has been credited by name in several works of science fiction.<ref>{{cite journal | journal = [[Amazing Science-Fiction]] | last = Pohl | first = Frederik | author-link = Frederik Pohl | title = Gateway III — Beyond the Gate (Part 1 of 3) | page = 80 | publisher = Ultimate Pub. Co | year = 1983 | volume = 57 }} </ref><ref>{{cite book | last = Pohl | first = Frederik | author-link = Frederik Pohl | title = [[Heechee Rendezvous]] | page = 91 | publisher = [[Ballantine Books]] | year = 1983 | volume = 3 | work = Heechee Saga | isbn = 0-345-30062-9 }} </ref><ref>{{Cite book | last1 = Clarke | first1 = Arthur C. | authorlink1 = Arthur C. Clarke | last2 = Pohl | first2 = Frederik | authorlink2 = Frederik Pohl | title = [[The Last Theorem]] |date=February 2009 | page = 55 | publisher = [[HarperCollins|HarperVoyager]] | location = London | isbn = 978-0-00-729002-4 }} </ref><ref>{{Cite book | last = Forward | first = Robert L. | author-link = Robert L. Forward | title = [[Starquake (novel)|Starquake]] | year = 1985 | page = [https://archive.org/details/dragonsegg00robe/page/ v] | publisher = [[Ballantine Books|Ballantine]] | location = London | isbn = 978-0-345-28349-8 }} </ref> [[Frederik Pohl]], who used the idea in several of his stories, once wrote that, of all the [[non-rocket spacelaunch]] concepts, he liked the Lofstrom Loop "best of all."<ref>{{cite journal | journal = [[Amazing Science-Fiction]] | title = Interview with Frederik Pohl | page = 98 | publisher = Ultimate Pub. Co | year = 1995 | volume = 69 | issue = 590 | url = https://books.google.com/books?id=UG0sAQAAIAAJ&q=best.of.all }} </ref>
As an electrical engineer, Lofstrom specializes in [[mixed-signal integrated circuit]] design. A paper he wrote on [[boundary scan]] methods was one of two to receive an Honorable Mention at the 1997 [[IEEE]] International Test Conference.<ref>{{cite book | title = IEEE International Test Conference Proceedings | page = 8 | year = 1997 | isbn = 0-7803-4210-0 }} [https://books.google.com/books?id=z0JGAQAAIAAJ&q=%22Early+Capture+for+Boundary+Scan+Timing+Measurements.%22] </ref> One of his 9 patents is for a way to read an individual digital ID for [[integrated circuits]] that arises from random atomic variations inherent in the [[semiconductor device fabrication]] process.<ref>{{cite patent | inventor-last = Lofstrom | inventor-first = Keith | inventorlink = Keith Lofstrom | publication-date = Dec 12, 2000 | issue-date = Dec 12, 2000 | title = System for providing an integrated circuit with a unique identification | country-code = US | description = | patent-number = 6161213 }} </ref><ref>{{cite web | title = A unique, repeatable, individual digital ID | url = http://www.siidtech.com/index.html | date = Nov 30, 2007 | access-date = 2011-07-24 }} </ref><ref>{{cite journal | last1 = Lofstrom | first1 = K. | last2 = Daasch | first2 = W. | last3 = Taylor | first3 = D. | title = IC Identification Circuit using Device Mismatch | journal = 2000 IEEE International Solid-State Circuits Conference Digest of Technical Papers | id = IEEE Cat. No. OOCH37056 | volume = 43 | url = http://www.siidtech.com/isscc2K.pdf | access-date = 2011-07-24 }} </ref>
One of his more recent efforts in speculative space systems is [http://server-sky.com/ServerSky Server Sky], a very large [[satellite constellation]] in Earth orbit using [[thin-film solar cells]] to power [[data center]] computers integrated into the same [[Wafer (electronics)|wafers]] as the PV cells.<ref>{{cite journal | last = Lofstrom | first = Keith | author-link = Keith Lofstrom | journal = Online Journal of Space Communication | title = Server Sky - Data Centers in Orbit | issue = 16 | date = Winter 2010 | url = http://spacejournal.ohio.edu/issue16/lofstrom.html }} </ref>
He is signed up for [[cryopreservation]] with the [[Alcor Life Extension Foundation]], since 1992.<ref name="Alcor" />
== References ==
{{Reflist}}
== External links == * [http://www.keithl.com/ Personal website] * [http://www.kl-ic.com/index.html KLIC] - IC design consultancy
{{DEFAULTSORT:Lofstrom, Keith}} [[Category:Space advocates]] [[Category:Cryonicists]] [[Category:Living people]] [[Category:Date of birth missing (living people)]] [[Category:1953 births]] [[Category:UC Berkeley College of Engineering alumni]] [[Category:20th-century American inventors]] [[Category:21st-century American inventors]] [[Category:Scientists from Portland, Oregon]] [[Category:Activists from Portland, Oregon]]