Keith Lofstrom is an American electrical engineer. He has a BSEE and MSEE from University of California, Berkeley. He is more widely known in the space advocacy community for a ground-based space launcher design, the Launch Loop, for which he has been credited by name in several works of science fiction. 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."
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. 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.
One of his more recent efforts in speculative space systems is Server Sky, a very large satellite constellation in Earth orbit using thin-film solar cells to power data center computers integrated into the same wafers as the PV cells.
- Lofstrom, Keith (1975), "Sinusoidal supply Josephson logic", U.C. Berkeley masters thesis
- Lofstrom, Keith H. (8–10 July 1985). "The launch loop -- a low cost Earth-to-high orbit launch system - Paper 85-1368" (PDF). Monterey, CA: 21st AIAA, SAE, ASME, and ASEE, Joint Propulsion Conference.
- Radley, Charles (September 14, 2009). "Local inventor says launch loop would greatly reduce cost of space travel". Gadgets and Tech: Portland Science Examiner. San Francisco: Examiner.com.
- Alexander Bolonkin (2006). "8". In Badescu, Viorel; Cathcart, Richard Brook; Schuiling, Roelof D. Space Towers. Macro-engineering: a challenge for the future. Springer. pp. 146–7. ISBN 1-4020-3739-2.
- Pohl, Frederik (1983). "Gateway III — Beyond the Gate (Part 1 of 3)". Amazing Science-Fiction. Ultimate Pub. Co. 57: 80.
- Pohl, Frederik (1983). Heechee Rendezvous. Heechee Saga. 3. Ballantine Books. p. 91. ISBN 0-345-30062-9.
- Clarke, Arthur C.; Pohl, Frederik (February 2009). The Last Theorem. London: HarperVoyager. p. 55. ISBN 978-0-00-729002-4.
- Forward, Robert L. (1985). Starquake. London: Ballantine. p. v. ISBN 978-0-345-28349-8.
- "Interview with Frederik Pohl". Amazing Science-Fiction. Ultimate Pub. Co. 69 (590): 98. 1995.
- IEEE International Test Conference Proceedings. 1997. p. 8. ISBN 0-7803-4210-0. 
- US 6161213, Lofstrom, Keith, "System for providing an integrated circuit with a unique identification", published Dec 12, 2000, issued Dec 12, 2000
- "A unique, repeatable, individual digital ID". Nov 30, 2007. Retrieved 2011-07-24.
- Lofstrom, K.; Daasch, W.; Taylor, D. "IC Identification Circuit using Device Mismatch" (PDF). 2000 IEEE International Solid-State Circuits Conference Digest of Technical Papers. 43. IEEE Cat. No. OOCH37056. Retrieved 2011-07-24.
- Lofstrom, Keith (Winter 2010). "Server Sky - Data Centers in Orbit". Online Journal of Space Communication (16).