Margaret Hamilton (software engineer)

Margaret Elaine Heafield was born August 17, 1936, in Paoli, Indiana, to Kenneth Heafield and Ruth Esther Heafield ({{Nee|Partington}}).{{cite web|title=Ruth Esther Heafield|url=http://wujekcalcaterra.tributes.com/show/Ruth-Esther-Heafield-89810802|url-status=live|archive-url=https://web.archive.org/web/20141216014535/http://wujekcalcaterra.tributes.com/show/Ruth-Esther-Heafield-89810802|archive-date=December 16, 2014|access-date=December 15, 2014|website=Wujek-Calcaterra & Sons – Tributes.com}} The family later moved to Michigan,{{Cite news|date=December 10, 1952|title=Commings, Goings and Events|work=The Evening News|location=Sault Ste. Marie, Michigan|url=https://www.newspapers.com/clip/34522969/the_evening_news/}} where Margaret graduated from Hancock High School in 1954.

She studied mathematics at the University of Michigan in 1955 before transferring to Earlham College, where her mother had been a student.{{Cite web|title=Pioneers in Computer Science|url=https://cs.usu.edu/news/pioneers-in-cs-margaret-hamilton|url-status=dead|archive-url=https://web.archive.org/web/20160917191701/https://cs.usu.edu/news/pioneers-in-cs-margaret-hamilton|archive-date=September 17, 2016|access-date=May 25, 2019|website=Utah State University}}{{Cite news|date=August 15, 1969|title=Former Earlham Student Had Role in Moon Flight|work=Palladium-Item|location=Richmond, Indiana|url=https://www.newspapers.com/clip/34523809/palladiumitem/|via=Newspapers.com}} She earned a BA in mathematics with a minor in philosophy in 1958.{{Cite web|title=2009 Outstanding Alumni and Distinguished Service Awards|url=http://www.earlham.edu/alumni/homecoming-and-reunions/alumni-awards/award-recipient-archives/2009-outstanding-alumni-and-distinguished-service-awards/|archive-url=https://web.archive.org/web/20150518094553/http://www.earlham.edu/alumni/homecoming-and-reunions/alumni-awards/award-recipient-archives/2009-outstanding-alumni-and-distinguished-service-awards/|archive-date=May 18, 2015|access-date=December 15, 2014|website=Earlham College}} She cites Florence Long, the head of the math department at Earlham, as helping with her desire to pursue abstract mathematics and become a mathematics professor.{{Cite web|title=The Woman Who Taught Me – Margaret Hamilton MAKERS Moment|url=https://www.makers.com/videos/596d0c549efa894cdf38430b|url-status=live|archive-url=https://web.archive.org/web/20190525203858/https://www.makers.com/videos/596d0c549efa894cdf38430b|archive-date=May 25, 2019|access-date=May 6, 2019|website=Makers.com|language=en-us}}

She says her poet father and headmaster grandfather inspired her to include a minor in philosophy in her studies.{{Cite news|date=July 20, 2016|title=Margaret Hamilton: The Untold Story of the Woman Who Took Us to the Moon|language=en-US|newspaper=Futurism|url=http://futurism.com/margaret-hamilton-the-untold-story-of-the-woman-who-took-us-to-the-moon/|url-status=live|access-date=December 12, 2016|archive-url=https://web.archive.org/web/20161220104403/http://futurism.com/margaret-hamilton-the-untold-story-of-the-woman-who-took-us-to-the-moon/|archive-date=December 20, 2016}}

In Boston, Hamilton initially intended to enroll in graduate study in abstract mathematics at Brandeis University.{{Cite book|url=https://books.google.com/books?id=aWGHDwAAQBAJ&pg=RA2-PA62|title=Technical Innovation in American History: An Encyclopedia of Science and Technology|date=February 28, 2019|publisher=ABC-Clio|isbn=978-1-61069-094-2|editor-last=Welch|editor-first=Rosanne|volume=3|pages=62|language=en|editor-last2=Lamphier|editor-first2=Peg A.}} However, in mid-1959, Hamilton began working for Edward Norton Lorenz, in the meteorology department at Massachusetts Institute of Technology (MIT). She developed software for predicting weather, programming on the LGP-30 and the PDP-1 computers at Marvin Minsky's Project MAC.{{cite journal |url=http://eaps4.mit.edu/research/Lorenz/The_Statistical_Prediction_of_Solutions_1962.pdf |last=Lorenz |first=Edward |title=The statistical prediction of solutions of dynamic equations |date=March 1962 |journal=Proceedings of the International Symposium on Numerical Weather Prediction in Tokyo, November 7–13, 1960 |pages=629–635 |publisher=The Meteorological Society of Japan |access-date=September 3, 2019 |archive-date=May 23, 2019 |archive-url=https://web.archive.org/web/20190523190103/http://eaps4.mit.edu/research/Lorenz/The_Statistical_Prediction_of_Solutions_1962.pdf |url-status=dead }}{{cite book |url=https://books.google.com/books?id=gPGZJ_YuMwgC&pg=PA480 |title=American Women of Science Since 1900 |last=Wayne |first=Tiffany K. |publisher=ABC-Clio |year=2011 |isbn=978-1-59884-158-9 |pages=480–82|access-date=April 29, 2016|archive-url=https://web.archive.org/web/20150317110451/http://books.google.com/books?id=gPGZJ_YuMwgC&pg=PA480|archive-date=March 17, 2015|url-status=live}}{{Cite book |title=Hackers: Heroes of the Computer Revolution |last=Levy |first=Steven |publisher=Doubleday |year=1984 |isbn=0-385-19195-2 |pages=Chapter 5:The Midnight Computer Wiring Society|title-link=Hackers: Heroes of the Computer Revolution}} Her work contributed to Lorenz's publications on chaos theory. At the time, computer science and software engineering were not yet established disciplines; instead, programmers learned on the job with hands-on experience. She moved on to another project in the summer of 1961, and hired and trained Ellen Fetter as her replacement.{{Cite web |url=https://www.quantamagazine.org/hidden-heroines-of-chaos-ellen-fetter-and-margaret-hamilton-20190520/ |title=The Hidden Heroines of Chaos |last=Sokol |first=Joshua |date=May 20, 2019 |website=Quanta Magazine |access-date=May 25, 2019}}

From 1961 to 1963, Hamilton worked on the Semi-Automatic Ground Environment (SAGE) Project at the MIT Lincoln Lab, where she was one of the programmers who wrote software for the prototype AN/FSQ-7 computer (the XD-1), used by the U.S. Air Force to search for possibly unfriendly aircraft.{{Cite web |url=http://www.computerhistory.org/atchm/2017-chm-fellow-margaret-hamilton/ |last=Spicer |first=Dan |title=2017 CHM Fellow Margaret Hamilton |website=Computer History Museum |date=April 27, 2017 |access-date = February 11, 2019 |archive-url = https://web.archive.org/web/20190212190351/https://www.computerhistory.org/atchm/2017-chm-fellow-margaret-hamilton/ |archive-date = February 12, 2019 |url-status=live}} She also wrote software for a satellite tracking project at the Air Force Cambridge Research Laboratories. The SAGE Project was an extension of Project Whirlwind, started by MIT to create a computer system that could predict weather systems and track their movements using simulators. SAGE was soon developed for military use in anti-aircraft air defense. Hamilton said:

{{Blockquote|What they used to do when you came into this organization as a beginner, was to assign you this program which nobody was able to ever figure out or get to run. When I was the beginner they gave it to me as well. And what had happened was it was tricky programming, and the person who wrote it took delight in the fact that all of his comments were in Greek and Latin. So I was assigned this program and I actually got it to work. It even printed out its answers in Latin and Greek. I was the first one to get it to work.{{Cite web |url=http://authors.library.caltech.edu/5456/1/hrst.mit.edu/hrs/apollo/public/conference1/hamilton-intro.htm |title=AGC – Conference 1: Margaret Hamilton's introduction |website=authors.library.caltech.edu |access-date=December 9, 2015|archive-url = https://web.archive.org/web/20160131233720/http://authors.library.caltech.edu/5456/1/hrst.mit.edu/hrs/apollo/public/conference1/hamilton-intro.htm|archive-date = January 31, 2016|url-status=live |df=mdy-all}}}}

It was her efforts on this project that made her a candidate for the position at NASA as the lead developer for Apollo flight software.

File:Margaret Hamilton - restoration.jpg

File:Margaret Hamilton in action.jpg

Hamilton learned of the Apollo project in 1965 and wanted to get involved due to it being "very exciting" as a Moon program.{{Cite news |last=Sheehan |first=Alan H. |date=November 1, 1972 |title=Putting 'Eagle' on course |url=https://www.newspapers.com/article/the-boston-globe/35911962/?locale=en-CA |access-date=January 9, 2024 |work=The Boston Globe |pages=24}} She joined the MIT Instrumentation Laboratory, which developed the Apollo Guidance Computer for the Apollo lunar exploration program. Hamilton was the first programmer hired for the Apollo project at MIT and the first female programmer in the project,{{Cite web |last1=Magazine |first1=Smithsonian |last2=George |first2=Alice |title=Margaret Hamilton Led the NASA Software Team That Landed Astronauts on the Moon |url=https://www.smithsonianmag.com/smithsonian-institution/margaret-hamilton-led-nasa-software-team-landed-astronauts-moon-180971575/ |access-date=March 5, 2023 |website=Smithsonian Magazine |language=en}} and later became Director of the Software Engineering Division.{{Cite web |title=Margaret Hamilton 2017 Fellow |url=http://www.computerhistory.org/fellowawards/hall/margaret-hamilton |url-status=live |archive-url=https://web.archive.org/web/20170629015545/http://www.computerhistory.org/fellowawards/hall/margaret-hamilton/ |archive-date=June 29, 2017 |access-date=June 26, 2017 |website=Computer History Museum}} She was responsible for the team writing and testing all on-board in-flight software for the Apollo spacecraft's Command and Lunar Module and for the subsequent Skylab space station.{{cite web |url=http://www.nasa.gov/50th/50th_magazine/scientists.html |title=NASA Engineers and Scientists-Transforming Dreams Into Reality |website=NASA|access-date=July 29, 2010|archive-url=https://web.archive.org/web/20100629170224/http://www1.nasa.gov/50th/50th_magazine/scientists.html|archive-date=June 29, 2010|url-status=live}}{{cite report |url=http://klabs.org/history/history_docs/mit_docs/1711.pdf |last=Hoag |first=David |title=The History of Apollo On-board Guidance, Navigation, and Control |date=September 1976 |publisher=Charles Stark Draper Laboratory|access-date=September 10, 2016|archive-url=https://web.archive.org/web/20161105060425/http://klabs.org/history/history_docs/mit_docs/1711.pdf|archive-date=November 5, 2016|url-status=live}}{{Cite web |url=http://klabs.org/home_page/hamilton.htm |title=About Margaret Hamilton |website=klabs.org |archive-url=https://web.archive.org/web/20101206145513/http://klabs.org/home_page/hamilton.htm |archive-date=December 6, 2010 |access-date=May 25, 2019}} Another part of her team designed and developed the systems software. This included error detection and recovery software such as restarts and the Display Interface Routines (also known as the Priority Displays), which Hamilton designed and developed.{{cite report |url=http://www.ibiblio.org/apollo/hrst/archive/1706.pdf |last=Green |first=Alan |title=Keyboard and Display Program and Operation |page=29 |date=June 1967 |publisher=Charles Stark Draper Laboratory|access-date=September 10, 2016|archive-url=https://web.archive.org/web/20160717160137/http://www.ibiblio.org/apollo/hrst/archive/1706.pdf|archive-date=July 17, 2016|url-status=live}} She worked to gain hands-on experience during a time when computer science courses were uncommon and software engineering courses did not exist.

Her areas of expertise include systems design and software development, enterprise and process modeling, development paradigm, formal systems modeling languages, system-oriented objects for systems modeling and development, automated life-cycle environments, methods for maximizing software reliability and reuse, domain analysis, correctness by built-in language properties, open-architecture techniques for robust systems, full life-cycle automation, quality assurance, seamless integration, error detection and recovery techniques, human-machine interface systems, operating systems, end-to-end testing techniques, and life-cycle management techniques.{{Cite web |url=https://news.mit.edu/2016/scene-at-mit-margaret-hamilton-apollo-code-0817 |title=Scene at MIT: Margaret Hamilton's Apollo code |last=Weinstock |first=Maia |website=MIT News |date=August 17, 2016 |access-date=August 17, 2016 |archive-url = https://web.archive.org/web/20160818061951/http://news.mit.edu/2016/scene-at-mit-margaret-hamilton-apollo-code-0817 |archive-date = August 18, 2016 |url-status=live}} These techniques are intended to make code more reliable because they help programmers identify and fix errors sooner in the development process.

In one of the critical moments of the Apollo 11 mission, the Apollo Guidance Computer, together with the on-board flight software, averted an abort of the landing on the Moon. Three minutes before the lunar lander reached the Moon's surface, several computer alarms were triggered. According to software engineer Robert Wills, Buzz Aldrin entered the codes to request that the computer display altitude and other data on the computer’s screen. The system was designed to support seven simultaneous programs running, but Aldrin’s request was the eighth. This action was something he requested many times whilst working in the simulator. The result was a series of unexpected error codes during the live descent. The on-board flight software captured these alarms with the "never supposed to happen displays" interrupting the astronauts with priority alarm displays.{{cite web |url=https://www.thetimes.com/uk/science/article/moon-landing-memories-apollo-11-changed-civilisation-and-i-had-a-part-in-it-2b8mx53km?region=global%2Cglobal |title=Moon landing memories:'Apollo 11 changed civilisation and I had a part in it' |newspaper=The Times of London |date=July 15, 2019 |url-access=registration}}

Hamilton had prepared for just this situation years before:

{{Blockquote|There was one other failsafe that Hamilton likes to remember. Her "priority display" innovation had created a knock-on risk that astronaut and computer would slip out of synch just when it mattered most. As the alarms went off and priority displays replaced normal ones, the actual switchover to new programmes behind the screens was happening "a step slower" than it would today.

Hamilton had thought long and hard about this. It meant that if Aldrin, say, hit a button on the priority display too quickly, he might still get a "normal" response. Her solution: when you see a priority display, first count to

five.{{cite web |url=https://members.tortoisemedia.com/2019/07/13/nasa-margaret/content.html |website=Tortoise Media |last=Whittell |first=Giles |title=First Woman |date=July 13, 2004 |access-date=August 23, 2019 |archive-date=November 1, 2020 |archive-url=https://web.archive.org/web/20201101011649/https://members.tortoisemedia.com/2019/07/13/nasa-margaret/content.html |url-status=dead }}

}}

By some accounts, the astronauts had inadvertently left the rendezvous radar switch on, causing these alarms to be triggered (the claim that the radar was left on inadvertently by the astronauts is disputed by Robert Wills with the National Museum of Computing{{cite web |url=https://www.youtube.com/watch?v=B1J2RMorJXM&t=4124s |archive-url=https://ghostarchive.org/varchive/youtube/20211221/B1J2RMorJXM |archive-date=December 21, 2021| url-status=live | via=The National Museum of Computing|last=Wills |first=Robert |title=Light-years ahead| date=October 26, 2019}}{{cbignore}}). The computer was overloaded with interrupts caused by incorrectly phased power supplied to the lander's rendezvous radar.{{cite journal |last=Blair-Smith |first=Hugh |journal=IEEE Aerospace and Electronic Systems Magazine |volume=26 |issue=11 |pages=16–24 |title=System integration issues in Apollo 11 |date=November 7, 2011 |doi=10.1109/MAES.2011.6065654|s2cid=13420135 }} The program alarms indicated "executive overflows", meaning the guidance computer could not complete all of its tasks in real time and had to postpone some of them.{{cite book |last1=Collins |first1=Michael |last2=Aldrin |first2=Edwin E. Jr. |author-link2=Buzz Aldrin |editor-last=Cortright |editor-first=Edgar M |editor-link=Edgar Cortright |title=Apollo Expeditions to the Moon |url=http://www.hq.nasa.gov/pao/History/SP-350/cover.html |access-date=June 13, 2013 |date=1975 |publisher=NASA |location=Washington, D.C. |oclc=1623434 |id=NASA SP-350 |chapter=A Yellow Caution Light |chapter-url=https://history.nasa.gov/SP-350/ch-11-4.html |archive-url=https://web.archive.org/web/20080219204538/https://history.nasa.gov/SP-350/ch-9-5.html |archive-date=February 19, 2008 |url-status=live}} Chapter 11.4. The asynchronous executive designed by J. Halcombe Laning{{cite news |url=https://www.americanscientist.org/article/moonshot-computing |magazine=American Scientist |last=Hayes |first=Brian |title=Moonshot Computing |date=May–June 2019}}{{cite journal |url=http://www.doneyles.com/LM/Tales.html |last=Eyles |first=Don |title=Tales from the Lunar Module Guidance Computer|access-date=July 22, 2016|archive-url=https://web.archive.org/web/20160720013844/http://www.doneyles.com/LM/Tales.html|archive-date=July 20, 2016 |journal=27th Annual Guidance and Control Conference of the American Astronautical Society|url-status=live |via=DonEyles.com}}{{cite book |last=Mindell |first=David A. |title=Digital Apollo |publisher=MIT Press |year=2011 |page=149}} was used by Hamilton's team to develop asynchronous flight software:

{{Blockquote|Because of the flight software's system-software's error detection and recovery techniques that included its system-wide "kill and recompute" from a "safe place" restart approach to its snapshot and rollback techniques, the Display Interface Routines (AKA the priority displays) together with its man-in-the-loop capabilities were able to be created in order to have the capability to interrupt the astronauts' normal mission displays with priority displays of critical alarms in case of an emergency. This depended on our assigning a unique priority to every process in the software in order to ensure that all of its events would take place in the correct order and at the right time relative to everything else that was going on.Snyder, Lawrence and Henry, Ray Laura, "Fluency7 with Information Technology", Pearson, {{ISBN|0-13-444872-3}}}}

Hamilton's priority alarm displays interrupted the astronauts' normal displays to warn them that there was an emergency "giving the astronauts a go/no-go decision (to land or not to land)".{{Cite web |url=https://news.mit.edu/2009/apollo-vign-0717 |title=Recalling the 'Giant Leap' |last=Hamilton |first=Margaret |website=MIT News |date=July 17, 2009 |access-date=September 8, 2016 | archive-url = https://web.archive.org/web/20160915221805/http://news.mit.edu/2009/apollo-vign-0717| archive-date = September 15, 2016| url-status=live}} Jack Garman, a NASA computer engineer in mission control, recognized the meaning of the errors that were presented to the astronauts by the priority displays and shouted, "Go, go!" and they continued.{{Cite web |url=https://news.mit.edu/2009/apollo-vign-0717 |title=Recalling the 'Giant Leap' |last=Lickly |first=Dan |website=MIT News |date=July 17, 2009 |access-date=September 8, 2016 | archive-url = https://web.archive.org/web/20160915221805/http://news.mit.edu/2009/apollo-vign-0717| archive-date = September 15, 2016| url-status=live}} Paul Curto, a senior technologist who nominated Hamilton for a NASA Space Act Award, called Hamilton's work "the foundation for ultra-reliable software design".

Hamilton later wrote of the incident:

{{blockquote|The computer (or rather the software in it) was smart enough to recognize that it was being asked to perform more tasks than it should be performing. It then sent out an alarm, which meant to the astronaut, 'I'm overloaded with more tasks than I should be doing at this time and I'm going to keep only the more important tasks'; i.e., the ones needed for landing ... Actually, the computer was programmed to do more than recognize error conditions. A complete set of recovery programs was incorporated into the software. The software's action, in this case, was to eliminate lower priority tasks and re-establish the more important ones ... If the computer hadn't recognized this problem and taken recovery action, I doubt if Apollo 11 would have been the successful Moon landing it was.

|Letter from Margaret H. Hamilton, Director of Apollo Flight Computer Programming MIT Draper Laboratory, Cambridge, Massachusetts, titled "Computer Got Loaded", published in Datamation, March 1, 1971{{cite journal |url=https://wehackthemoon.com/people/margaret-hamilton-computer-got-loaded |last=Hamilton |first=Margaret H. |date=March 1, 1971 |title=Computer Got Loaded, letter to the editor of Datamation |journal=Datamation |type=Letter |issn=0011-6963 |archive-url=https://web.archive.org/web/20191203034856/https://wehackthemoon.com/people/margaret-hamilton-computer-got-loaded |archive-date=December 3, 2019 |url-status=dead}}}}

In 1976, Hamilton co-founded with Saydean Zeldin a company called Higher Order Software (HOS){{Cite book |url=https://archive.org/details/entrepreneursinh00robe |url-access=registration |title=Entrepreneurs in High Technology: Lessons from MIT and Beyond |last=Roberts |first=Edward B. |date=1991 |publisher=Oxford University Press |isbn=9780199762903 |pages=[https://archive.org/details/entrepreneursinh00robe/page/41 41] |language=en}} to further develop ideas about error prevention and fault tolerance emerging from their experience at MIT working on the Apollo program.{{Cite web |url=http://authors.library.caltech.edu/5456/1/hrst.mit.edu/hrs/apollo/public/people/mhamilton.htm |title=AGC Biography – Margaret Hamilton |date=May 9, 2002 |website=authors.library.caltech.edu |publisher=The Dibner Institute for the History of Science and Technology|archive-url=https://web.archive.org/web/20110725133604/http://authors.library.caltech.edu/5456/1/hrst.mit.edu/hrs/apollo/public/people/mhamilton.htm|archive-date=July 25, 2011|url-status=live|access-date=July 26, 2019}}{{cite report |url=https://apps.dtic.mil/dtic/tr/fulltext/u2/a198753.pdf#page=8 |title=Higher Order Software – Evaluation and Critique |last=Huber |first=Hartmut |date=August 1987 |publisher=Naval Surface Warfare Center |pages=2–1|archive-url=https://web.archive.org/web/20160507101136/http://www.dtic.mil/dtic/tr/fulltext/u2/a198753.pdf|archive-date=May 7, 2016|url-status=live|access-date=July 22, 2016}} They created a product called USE.IT, based on the HOS methodology they developed at MIT.M. Hamilton, S. Zeldin (1976) "Higher order software—A methodology for defining software" IEEE Transactions on Software Engineering, vol. SE-2, no. 1, Mar. 1976.Thompson, Arthur A.; Strickland, A. J., (1996), "Strategic Management: Concepts and Cases", McGraw-Hill Companies, {{ISBN|0-256-16205-0}}{{cite book |author=Rowena Barrett |title=Management, Labour Process and Software Development: Reality Bites |url=https://books.google.com/books?id=JWgAUAqhiv8C&pg=PA42 |date=June 1, 2004 |publisher=Routledge |isbn=978-1-134-36117-5 |page=42|access-date=April 29, 2016|archive-url=https://web.archive.org/web/20150317102138/http://books.google.com/books?id=JWgAUAqhiv8C&pg=PA42|archive-date=March 17, 2015|url-status=live}} It was successfully used in numerous government programs{{Cite book|last1=Hamilton|first1=Margaret|last2=Zeldin|first2=Saydean|title=Programming Symposium |chapter=Higher order software techniques applied to a space shuttle prototype program |date=1974|editor-last=Robinet|editor-first=B.|series=Lecture Notes in Computer Science|volume=19|language=en|publisher=Springer Berlin Heidelberg|pages=17–32|doi=10.1007/3-540-06859-7_121|isbn=978-3-540-37819-8}}{{Cite book |title=The Specification of Complex Systems |last=Cohen |first=B. |publisher=Addison-Wesley |year=1986 |isbn=0-201-14400-X}} including a project to formalize and implement C-IDEF, an automated version of IDEF, a modeling language developed by the U.S. Air Force in the Integrated Computer-Aided Manufacturing (ICAM) project.{{Cite journal |last=Paul |first=Lois |date=October 11, 1982 |title=Federal User Offers Free CAD/CAM Software |url=https://books.google.com/books?id=LW9X-GFY68sC&pg=PA9 |journal=Computerworld |volume=16 |issue=41 |pages=9 |via=Google Books}} In 1980, British-Israeli computer scientist David Harel published a proposal for a structured programming language derived from HOS from the viewpoint of and/or subgoals.{{cite journal |last=Harel |first=David |date=January 1980 |title=And/Or Programs: A New Approach to Structured Programming |url=http://www.wisdom.weizmann.ac.il/~harel/SCANNED.PAPERS/NewApproachToStructuredProgramming.pdf|url-status=live |journal=ACM Transactions on Programming Languages and Systems |publisher=ACM |volume=2 |issue=1 |pages=1–17 |doi=10.1145/357084.357085 |s2cid=966526 |issn=0164-0925|archive-url=https://web.archive.org/web/20190818232214/http://www.wisdom.weizmann.ac.il/~harel/SCANNED.PAPERS/NewApproachToStructuredProgramming.pdf|archive-date=August 18, 2019|access-date=October 14, 2016 |via=Weizmann Institute of Science}} Others have used HOS to formalize the semantics of linguistic quantifiers,

{{cite conference

|title=Abstract Control Structures and the Semantics of Quantifiers

|last=Cushing

|first=Steven

|doi=10.3115/980092.980093

|year=1983

|conference=EACL

|conference-url=https://dblp1.uni-trier.de/db/conf/eacl/eacl1983.html

|location=Pisa, Italy

|s2cid=10821594

|doi-access=free }}

and to formalize the design of reliable real-time embedded systems.{{Cite report |last=Holland |first=Michael |title=A Constrained Interface Refinement Method for Embedded System Design |date=June 1, 1997 |publisher=Department of Computing, Macquarie University |citeseerx=10.1.1.37.7895}}

Hamilton was the CEO of HOS through 1984 and left the company in 1985. In March 1986, she founded Hamilton Technologies, Inc. in Cambridge, Massachusetts. The company was developed around the Universal Systems Language (USL) and its associated automated environment, the 001 Tool Suite, based on her paradigm of development before the fact for systems design and software development.{{cite journal |last1=Hamilton |first1=Margaret |first2=William |last2=Hackler |title=Universal Systems Language: Lessons Learned from Apollo |journal=IEEE Computer |volume=41 |issue=12 |pages=34–43 |date=December 12, 2008 |doi=10.1109/MC.2008.541 |s2cid=15870726 |issn=1558-0814}}{{cite book |chapter-url=https://apps.dtic.mil/dtic/tr/fulltext/u2/a293427.pdf#page=23 |chapter=Overview of Hamilton Technologies, Inc. (HTI) 001 |title=Integrating 001 Tool Support in Feature-Oriented Domain Analysis Methodology |last=Krut |first=Robert W. |date=July 1993 |via=Defense Technical Information Center |publisher=Software Engineering Institute of Carnegie Mellon University|archive-url=https://web.archive.org/web/20190705080726/https://apps.dtic.mil/dtic/tr/fulltext/u2/a293427.pdf |archive-date=July 5, 2019 |url-status=live |access-date=May 26, 2019 |pages=13–15}}{{Cite report |title=An Integrated Formal Approach for Developing High Quality Software for Safety-Critical Systems |id=MIT-ANP-TR-035 |last1=Ouyang |first1=Meng |last2=Golay |first2=Michael W. |publisher=Massachusetts Institute of Technology|date=September 1995|hdl=1721.1/67642 }}

File:Margaret Hamilton 1989.jpg, 1989]]

Hamilton has been credited with naming the discipline of "software engineering".{{cite web | last=Cameron | first=Lori | title=First Software Engineer | website=IEEE Computer Society | date=October 5, 2018 | url=https://www.computer.org/publications/tech-news/events/what-to-know-about-the-scientist-who-invented-the-term-software-engineering | access-date=March 25, 2023}}{{cite web |url=https://www.youtube.com/watch?v=ZbVOF0Uk5lU&t=51 |title=ICSE 2018 – Plenary Sessions – Margaret Hamilton |publisher=ICSE 2018 |website=YouTube|date=May 31, 2018 |url-status=live|archive-url=https://web.archive.org/web/20180603154725/https://www.youtube.com/watch?v=ZbVOF0Uk5lU|archive-date=June 3, 2018|access-date=June 9, 2018}}{{cite web |url=http://www.nasa.gov/50th/50th_magazine/scientists.html |title=NASA Engineers and Scientists – Transforming Dreams Into Reality |last=Rayl |first=A.J.S. |date=October 16, 2008 |website=50th Magazine |publisher=NASA |access-date=November 25, 2016 |archive-date=June 29, 2010 |archive-url=https://web.archive.org/web/20100629170224/http://www1.nasa.gov/50th/50th_magazine/scientists.html |url-status=dead }}{{cite book |url=https://books.google.com/books?id=_ChmDwAAQBAJ&pg=PA60 |page=60 |last=Johnson |first=Jordan |date=2017 |title=Sputnik and the Space Race |publisher=Cavendish Square |isbn=9781502627223 |quote=With her colleagues, she developed the building blocks for modern 'software engineering,' a term Hamilton coined.}} Hamilton details how she came to make up the term "software engineering":

{{Blockquote|When I first came up with the term, no one had heard of it before, at least in our world. It was an ongoing joke for a long time. They liked to kid me about my radical ideas. It was a memorable day when one of the most respected hardware gurus explained to everyone in a meeting that he agreed with me that the process of building software should also be considered an engineering discipline, just like with hardware. Not because of his acceptance of the new 'term' per se, but because we had earned his and the acceptance of the others in the room as being in an engineering field in its own right.}}

When Hamilton started using the term "software engineering" during the early Apollo missions,{{cite web |url=http://www.nasa.gov/50th/50th_magazine/scientists.html |title=NASA Engineers and Scientists-Transforming Dreams Into Reality |last=Rayl |first=A.J.S. |date=October 16, 2008 |website=50th Magazine |publisher=NASA |access-date=December 27, 2014 | archive-url=https://web.archive.org/web/20141223112045/http://www.nasa.gov/50th/50th_magazine/scientists.html | archive-date=December 23, 2014 | url-status=live}} software development was not taken seriously compared to other engineering,{{Cite web |url=https://www.makers.com/margaret-hamilton |title=Makers:Margaret Hamilton Videos |website=Makers.com|access-date=September 5, 2017|archive-url=https://web.archive.org/web/20170905232654/https://www.makers.com/margaret-hamilton|archive-date=September 5, 2017|url-status=live}} nor was it regarded as a science. Hamilton was concerned with legitimizing software development as an engineering discipline.{{Cite web |url=https://www.computerhistory.org/fellowawards/hall/margaret-hamilton/ |title=Margaret Hamilton: 2017 Fellow Biography |website=Computer History Museum |access-date = February 11, 2019 |archive-url = https://web.archive.org/web/20190212190351/https://www.computerhistory.org/atchm/2017-chm-fellow-margaret-hamilton/ |archive-date = February 12, 2019 |url-status=live}} Over time the term "software engineering" gained the same respect as any other technical discipline.{{Cite web |url=https://medium.com/@verne/margaret-hamilton-the-engineer-who-took-the-apollo-to-the-moon-7d550c73d3fa#.cgnapquz2 |title=Margaret Hamilton, the Engineer Who Took the Apollo to the Moon |last=Verne |date=December 25, 2014 |website=Medium|url-status=live|archive-url=https://web.archive.org/web/20160413141900/https://medium.com/@verne/margaret-hamilton-the-engineer-who-took-the-apollo-to-the-moon-7d550c73d3fa#.cgnapquz2|archive-date=April 13, 2016|access-date=April 29, 2016}} The IEEE Software September/October 2018 issue celebrates the 50th anniversary of software engineering.{{Cite journal |last1=Erdogmus |first1=Hakan |last2=Medvidovic |first2=Nenad |last3=Paulisch |first3=Frances |date=September–October 2018 |title=50 Years of Software Engineering |journal=IEEE Software |volume=35 |issue=5 |pages=20–24 |doi=10.1109/MS.2018.3571240 |issn=0740-7459|doi-access=free }} Hamilton talks about "Errors" and how they influenced her work related to software engineering and how her language, USL, could be used to prevent the majority of "Errors" in a system.{{cite journal |last=Hamilton |first=Margaret H. |title=What the Errors Tell Us |journal=IEEE Software |volume=35 |issue=5 |year=2018 |pages=32–37 |issn=0740-7459 |doi=10.1109/MS.2018.290110447|s2cid=52896962 |doi-access=free }} With USL, rather than continuing to test for errors, her program was designed to keep most errors out of the system from the beginning.{{Cite web |date=May 29, 2024 |title=Margaret Hamilton |url=https://computerhistory.org/profile/margaret-hamilton/ |access-date=June 4, 2024 |website=CHM |language=en}} USL was created after her knowledge and experience from the Apollo mission, in which she determined a mathematical theory for systems and software.{{Cite web |date=May 29, 2024 |title=Margaret Hamilton |url=https://computerhistory.org/profile/margaret-hamilton/ |access-date=June 5, 2024 |website=CHM |language=en}} This method was then, and still is, highly impactful to the field of software engineering. Writing in Wired, Robert McMillan noted: "At MIT she assisted in the creation of the core principles in computer programming as she worked with her colleagues in writing code for the world's first portable computer".{{cite magazine |last=McMillan |first=Robert |title=Her code got humans on the moon – and invented software itself |url=https://www.wired.com/2015/10/margaret-hamilton-nasa-apollo/ |access-date=October 20, 2015 |magazine=Wired |date=October 13, 2015 |archive-url=https://web.archive.org/web/20151023035142/http://www.wired.com/2015/10/margaret-hamilton-nasa-apollo|archive-date=October 23, 2015|url-status=live |language=en-US}} Hamilton's innovations go beyond the feats of playing an important role in getting humans to the Moon. According to Wired{{'}}s Karen Tegan Padir: "She, along with that other early programming pioneer, COBOL inventor Grace Hopper, also deserve tremendous credit for helping to open the door for more women to enter and succeed in STEM fields like software."{{Cite magazine |url=https://www.wired.com/insights/2014/08/software-woman-heart-lunar-triumph/ |title=Software — and a Woman — at the Heart of Lunar Triumph |magazine=WIRED |date=August 21, 2014 |language=en-US|access-date=April 29, 2016|archive-url=https://web.archive.org/web/20160505045610/http://www.wired.com/insights/2014/08/software-woman-heart-lunar-triumph|archive-date=May 5, 2016|url-status=live}}{{Cite web |url=https://futurism.com/images/the-woman-who-put-men-on-the-moon-comic/ |title=The Women Who Put Men on the Moon |author=Luke Kingma |newspaper=Futurism|access-date=July 20, 2016|archive-url=https://web.archive.org/web/20160723082045/http://futurism.com/images/the-woman-who-put-men-on-the-moon-comic|archive-date=July 23, 2016|url-status=live}}

In 2017, a "Women of NASA" LEGO set went on sale featuring minifigures of Hamilton, Mae Jemison, Sally Ride, and Nancy Grace Roman. The set was initially proposed by Maia Weinstock as a tribute to the women's contributions to NASA history, and Hamilton's section of the set features a recreation of her famous 1969 photo posing with a stack of her software listings.{{cite news |last=Mosher |first=Dave |url=http://www.businessinsider.com/lego-female-scientists-engineers-nasa-kit-2017-11 |title=Lego's 'Women of NASA' toy set is finally on sale — and it's already Amazon's best-selling toy |magazine=Business Insider |date=June 22, 2017 |access-date=November 3, 2017 |archive-url=https://web.archive.org/web/20171107025548/http://www.businessinsider.com/lego-female-scientists-engineers-nasa-kit-2017-11 |archive-date=November 7, 2017 |url-status=live}}{{cite news |url=https://arstechnica.com/science/2017/10/a-new-lego-set-honors-the-women-of-nasa-and-it-looks-pretty-awesome/ |title=A new LEGO set honors the women of NASA—and it looks pretty awesome |first=Eric |last=Berger |work=Ars Technica |location=US |date=October 18, 2017}}

In 2019, to celebrate 50 years after the Apollo landing, Google decided to make a tribute to Hamilton. The mirrors at the Ivanpah Solar Power Facility were configured to create a picture of Hamilton and the Apollo 11 by moonlight.{{Cite web |url=https://blog.google/products/maps/margaret-hamilton-apollo-11-tribute/ |title=A moonlit tribute to a moon landing icon |date=July 18, 2019 |website=Google |language=en|access-date=December 31, 2019}}

Margo Madison, a fictional NASA engineer in the alternate history series For All Mankind, was inspired by Hamilton.{{cite web |last=Guinnessy |first=Paul |title=Review: For All Mankind rewrites history with a prolonged space race |url=https://pubs.aip.org/physicstoday/Online/5167/Review-For-All-Mankind-rewrites-history-with-a |work=Physics Today |date=November 20, 2019 |access-date=December 1, 2023 }}

File:Hamilton Medal of Freedom from Obama.jpg awards the Presidential Medal of Freedom to Hamilton in 2016]]

File:Honoris Causa of Margaret Hamilton.png

• In 1986, Hamilton received the Augusta Ada Lovelace Award by the Association for Women in Computing.{{Cite web |url=http://www.awc-hq.org/ada-lovelace-awards.html |title=Ada Lovelace Awards |website=Association for Women in Computing|archive-url=https://web.archive.org/web/20160414183958/http://www.awc-hq.org/ada-lovelace-awards.html|archive-date=April 14, 2016|url-status=live}}
• In 2003, she was given the NASA Exceptional Space Act Award for scientific and technical contributions. The award included $37,200, the largest amount awarded to any individual in NASA's history.Michael Braukus NASA News [http://www.nasa.gov/home/hqnews/2003/sep/HQ_03281_Hamilton_Honor.html "NASA Honors Apollo Engineer"] {{Webarchive|url=https://web.archive.org/web/20101124231727/http://www.nasa.gov/home/hqnews/2003/sep/HQ_03281_Hamilton_Honor.html |date=November 24, 2010 }} (September 3, 2003){{cite press release |website=NASA News |url=https://history.nasa.gov/alsj/a11/a11Hamilton.html |title=NASA Honors Apollo Engineer|archive-url=https://web.archive.org/web/20171226003423/https://history.nasa.gov/alsj/a11/a11Hamilton.html |archive-date=December 26, 2017 |date=September 3, 2003|url-status=live |quote='The Apollo flight software Ms. Hamilton and her team developed was truly a pioneering effort,' said NASA Administrator Sean O'Keefe. 'The concepts she and her team created became the building blocks for modern "software engineering." It's an honor to recognize Ms. Hamilton for her extraordinary contributions to NASA,' he said.}}
• In 2009, she received the Outstanding Alumni Award from Earlham College.
• In 2016, she received the Presidential Medal of Freedom from Barack Obama, the highest civilian honor in the United States.{{cite web |url=https://www.bbc.com/news/world-us-canada-38076123 |title=Honour for software writer on Apollo moon mission |date=November 23, 2016 |website=BBC News |language=en |access-date=November 23, 2016|archive-url=https://web.archive.org/web/20161124030838/http://www.bbc.com/news/world-us-canada-38076123|archive-date=November 24, 2016|url-status=live}}{{cite web |url=http://www.cbsnews.com/news/white-house-medal-of-freedom-margaret-hamilton-grace-hopper/ |title=White House honors two of tech's female pioneers |website=CBS News |date=November 23, 2016 |access-date=June 7, 2017|archive-url=https://web.archive.org/web/20170427153651/http://www.cbsnews.com/news/white-house-medal-of-freedom-margaret-hamilton-grace-hopper/|archive-date=April 27, 2017|url-status=live}}{{Cite web |last=Almeida |first=Andres |date=November 22, 2016 |title=Margaret Hamilton Awarded Presidential Medal of Freedom |url=http://www.nasa.gov/feature/margaret-hamilton-apollo-software-engineer-awarded-presidential-medal-of-freedom |access-date=July 26, 2022 |website=NASA}}
• On April 28, 2017, she received the Computer History Museum Fellow Award, which honors exceptional men and women whose computing ideas have changed the world.{{Cite web |url=https://www.youtube.com/watch?v=i9vi04O6fFw&index=1&list=PLQsxaNhYv8dZhOrds54RHNc9cj89r5Nt6#t=42m20s |archive-url=https://ghostarchive.org/varchive/youtube/20211221/i9vi04O6fFw |archive-date=December 21, 2021 |url-status=live|title=The 2017 Fellow Award Acceptance Speech |website=Computer History Museum|date=August 4, 2017 }}{{cbignore}}
• In 2018, she was awarded an honorary doctorate degree by the Polytechnic University of Catalonia.{{Cite web |url=https://www.upc.edu/en/press-room/news/investiture-of-margaret-hamilton-as-an-honorary-doctor-of-upc |title=Investiture of scientist Margaret Hamilton as an honorary doctor of the UPC |website=Polytechnic University of Catalonia|access-date=January 25, 2019|archive-url=https://web.archive.org/web/20190126113933/https://www.upc.edu/en/press-room/news/investiture-of-margaret-hamilton-as-an-honorary-doctor-of-upc|archive-date=January 26, 2019|url-status=live |date=October 18, 2018}}
• In 2019, she was awarded The Washington Award.{{Cite web |url=http://www.thewashingtonaward.com/ |title=Margaret Hamilton Accepts 2019 Washington Award Nomination |publisher=Western Society of Engineers |date=February 22, 2019}}
• In 2019, she was awarded an honorary doctorate degree by Bard College.{{Cite web |url=https://www.annandaleonline.org/s/990/bp18/interior.aspx?sid=990&gid=1&pgid=2887 |title=Bard College - 2019 Honorary Degree Recipients |website=Bard Annandale Online |publisher=Bard College |date=May 21, 2019}}
• In 2019, she was awarded the Intrepid Lifetime Achievement Award.{{Cite web |url=https://support.intrepidmuseum.org/campaign/salute-to-freedom-gala/c216914 |title=Salute to Freedom Gala |publisher=Intrepid Museum |date=May 23, 2019 |access-date=September 24, 2019 |archive-date=September 24, 2019 |archive-url=https://web.archive.org/web/20190924162857/https://support.intrepidmuseum.org/campaign/salute-to-freedom-gala/c216914 |url-status=dead }}
• In 2022, she was inducted into the National Aviation Hall of Fame in Dayton, Ohio.{{cite web |title=Enshrinee Margaret Hamilton |url=https://nationalaviation.org/enshrinee/margaret-hamilton/ |website=nationalaviation.org |publisher=National Aviation Hall of Fame |access-date=February 8, 2023}}

• {{Cite journal |last1=Hamilton |first1=M. |last2=Zeldin |first2=S. |date=March 1976 |title=Higher Order Software—A Methodology for Defining Software |journal=IEEE Transactions on Software Engineering |volume=SE-2 |issue=1 |pages=9–32 |doi=10.1109/TSE.1976.233798|s2cid=7799553 }}
• {{Cite journal |last1=Hamilton |first1=M. |last2=Zeldin |first2=S. |date=January 1, 1979 |title=The relationship between design and verification |journal=Journal of Systems and Software |volume=1 |pages=29–56 |doi=10.1016/0164-1212(79)90004-9}}
• Hamilton, M. (April 1994). [http://www.htius.com/Articles/Inside_DBTF.pdf "Inside Development Before the Fact"]. (Cover story). Special Editorial Supplement. 8ES-24ES. Electronic Design.
• Hamilton, M. (June 1994). [http://www.htius.com/Articles/001_A_Full_Life_Cycle.pdf "001: A Full Life Cycle Systems Engineering and Software Development Environment"]. (Cover story). Special Editorial Supplement. 22ES-30ES. Electronic Design.
• Hamilton, M.; Hackler, W. R. (2004). "Deeply Integrated Guidance Navigation Unit (DI-GNU) Common Software Architecture Principles". (Revised December 29, 2004). DAAAE30-02-D-1020 and DAAB07-98-D-H502/0180, Picatinny Arsenal, NJ, 2003–2004.
• Hamilton, M.; Hackler, W. R. (2007). "[http://www.htius.com/Articles/36.pdf Universal Systems Language for Preventative Systems Engineering]", Proc. 5th Ann. Conf. Systems Eng. Res. (CSER), Stevens Institute of Technology, Mar. 2007, paper #36.
• {{cite journal | last1=Hamilton | first1=Margaret H. | last2=Hackler | first2=William R. | title=8.3.2 a Formal Universal Systems Semantics for SysML | journal=Incose International Symposium | publisher=Wiley | volume=17 | issue=1 | year=2007 | issn=2334-5837 | doi=10.1002/j.2334-5837.2007.tb02952.x | pages=1333–1357| s2cid=57214708 }}
• {{cite journal | last1=Hamilton | first1=Margaret H. | last2=Hackler | first2=William R. | title=Universal Systems Language: Lessons Learned from Apollo | journal=Computer | publisher=Institute of Electrical and Electronics Engineers (IEEE) | volume=41 | issue=12 | year=2008 | issn=0018-9162 | doi=10.1109/mc.2008.541 | pages=34–43}}
• {{Cite journal |last=Hamilton |first=M. H. |date=September 2018 |title=What the Errors Tell Us |journal=IEEE Software |volume=35 |issue=5 |pages=32–37 |doi=10.1109/MS.2018.290110447|s2cid=52896962 |doi-access=free }}

Hamilton has a sister, Kathryn Heafield.{{Cite web|last=Onwuamaegbu|first=Natachi|date=July 20, 2019|title=Margaret Hamilton's sister shares her memories as Seattle's seniors celebrate the 50th anniversary of the moon landing|url=https://www.seattletimes.com/life/margaret-hamiltons-sister-shares-her-memories-as-seattles-seniors-celebrate-the-50th-anniversary-of-the-moon-landing/|access-date=August 10, 2019|website=The Seattle Times|language=en-US}}

She met her first husband, James Cox Hamilton,{{cite news|last=Stickgold|first=Emma|date=August 31, 2014|title=James Cox Hamilton, at 77; lawyer was quiet warrior for First Amendment|work=The Boston Globe|url=https://www.bostonglobe.com/metro/2014/08/30/james-cox-hamilton-mentor-young-lawyers-also-handled-aclu-cases/CGoF5qLYsNnUEap7BuTrGJ/story.html|url-status=live|access-date=December 15, 2014|archive-url=https://web.archive.org/web/20141216011645/http://www.bostonglobe.com/metro/2014/08/30/james-cox-hamilton-mentor-young-lawyers-also-handled-aclu-cases/CGoF5qLYsNnUEap7BuTrGJ/story.html|archive-date=December 16, 2014}} in the mid-1950s while attending college. They were married on June 15, 1958, the summer after she graduated from Earlham.{{Cite news|date=July 2, 1958|title=Wed In Earlham Meetinghouse Rite|work=Palladium-Item|location=Richmond, Indiana|url=https://www.newspapers.com/clip/34743426/palladiumitem/|access-date=August 10, 2019}} She briefly taught high school mathematics and French at a public school in Boston, Indiana. The couple then moved to Boston, Massachusetts, where they had a daughter, Lauren, born on November 10, 1959. They divorced in 1967 and Margaret married Dan Lickly two years later.{{Cite news|last=Sheehan|first=Alan H.|date=November 1, 1972|title=Putting Eagle on course|work=The Boston Globe|location=Boston, Massachusetts|url=https://www.newspapers.com/clip/35911962/the_boston_globe/|access-date=September 22, 2019}}

• List of pioneers in computer science

{{Reflist|30em}}

• {{cite magazine |title=One woman in a room full of men |magazine=The Telegraph Magazine |first=Eleanor |last=Steafel |location=London |publisher=Daily Telegraph plc. |pages=56–59, 61 |date=July 20, 2019 |oclc=69022829}}

{{commons category}}

{{Wikiquote|Margaret Hamilton}}

• [http://www.htius.com Hamilton Technologies, Inc.]
• [https://news.mit.edu/2016/scene-at-mit-margaret-hamilton-apollo-code-0817 MIT News]
• [https://www.makers.com/margaret-hamilton Margaret Hamilton] {{Webarchive|url=https://web.archive.org/web/20170905232654/https://www.makers.com/margaret-hamilton |date=September 5, 2017 }} Video produced by Makers: Women Who Make America
• [http://earlham.edu/margaret-hamilton/ Margaret Hamilton ’58 – Presidential Medal of Freedom Recipient] {{Webarchive|url=https://web.archive.org/web/20190730011433/http://earlham.edu/margaret-hamilton/ |date=July 30, 2019 }}: Earlham College profile

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