Question: In which year did first woman hired by the agency that operates the "Master Clock" become an American Astronomical Society member?

Context paragraphs:
Andrew Fraknoi: Andrew Fraknoi is an astronomy professor at Foothill College and the 2007 California Professor of the Year awarded by the Carnegie Foundation for the Advancement of Teaching and the Council for Advancement and Support of Education.  Fraknoi also won the Astronomical Society of the Pacific's 2007 Richard H. Emmons award, the American Institute of Physics's 2007 Andrew Gemant Award (given for a lifetime of contributions to the intersection of physics and culture), and the American Astronomical Society's 1994 Annenberg Foundation Award (for a lifetime of contributions to astronomy education.)  The International Astronomical Union has named Asteroid 4859 Asteroid Fraknoi to recognize his contributions to science education and to the public understanding of astronomy.  In 2013, he was elected to the Board of Trustees of the Friends of the Lick Observatory.

Herbert Friedman: Herbert Friedman (June 21, 1916 – September 9, 2000) was an American pioneer in the application of sounding rockets to solar physics, aeronomy, and astronomy.  He was also a statesman and public advocate for science.  During his lifetime, he was awarded the Eddington Medal of the Royal Astronomical Society, the National Medal of Science, the Henry Norris Russell Lectureship of the American Astronomical Society, the William Bowie Medal of the American Geophysical Union, the Wolf Foundation Prize in Physics, and the Albert A. Michelson Medal of the Franklin Institute (1972), among others.  He was elected a member of the National Academy of Sciences in 1960 and of the American Philosophical Society in 1964.

The Astronomical Journal: The Astronomical Journal (often abbreviated "AJ" in scientific papers and references) is a peer-reviewed monthly scientific journal owned by the American Astronomical Society and currently published by IOP Publishing.  It is one of the premier journals for astronomy in the world.  Until 2008, the journal was published by the University of Chicago Press on behalf of the American Astronomical Society.  The reasons for the change were given by the society as the desire of the University of Chicago Press to revise its financial arrangement and their plans to change from the particular software that had been developed in-house.  The other two publications of the society, the "Astrophysical Journal" and its supplement series, followed in January 2009.

Royal Astronomical Society: The Royal Astronomical Society (RAS) is a learned society that began as the Astronomical Society of London in 1820 to support astronomical research (mainly carried on at the time by 'gentleman astronomers' rather than professionals).  It became the Royal Astronomical Society in 1831 on receiving its Royal Charter from William IV.  A Supplemental Charter in 1915 opened up the fellowship to women.  It is the UK adhering organisation to the International Astronomical Union and a member of the Science Council, and encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science.  Meetings are held in Burlington House, in Piccadilly, London and across the United Kingdom (UK).  They are involved in the production of astronomical journals and periodicals.  The society has over 3000 members, around a third of whom live outside the UK.  In addition, those members of the public who have an interest in astronomy and geophysics and wish to support the work of the society may become Friends of the RAS.

Daniel Johnston (scientist): Daniel Johnston is an American neuroscientist, having held the Karl Folkers Chair in Interdisciplinary Biomedical Research at University of Texas at Austin.  He is a member of the Royal Astronomical Society and American Astronomical Society and International Astronomical Union.

United States Naval Observatory: The United States Naval Observatory (USNO) is one of the oldest scientific agencies in the United States, with a primary mission to produce Positioning, Navigation and Timing (PNT) for the United States Navy and the United States Department of Defense.  Located in Northwest Washington, D.C. at the Northwestern end of Embassy Row, it is one of the pre-1900 astronomical observatories located in an urban area; at the time of its construction, it was far from the light pollution thrown off by the (then-smaller) city center.  The USNO operates the "Master Clock", which provides precise time to the GPS satellite constellation run by the United States Air Force.  The USNO performs radio VLBI-based positions of quasars with numerous global collaborators, in order to produce Earth Orientation parameters.

Heather A. Knutson: Heather A. Knutson is an astrophysicist and assistant professor at California Institute of Technology in the Division of Geological and Planetary Sciences.  Her research is focused on the study of exoplanets, their composition and formation.  She won the American Astronomical Society's Newton Lacy Pierce Prize in Astronomy for her work in exoplanetary atmospheres. <ref name="https://aas.org/grants-and-prizes/newton-lacy-pierce-prize-astronomy">American Astronomical Society: Newton Lacy Pierce Prize in Astronomy | American Astronomical Society, accessdate: June 15, 2016</ref>

Neb Duric: Neb Duric (born 1955) is a Serbian-born American astrophysicist.  He received his PhD in astrophysics in 1984 from the University of Toronto, where he earned the Royal Astronomical Society of Canada Gold Medal for academic excellence.  After a postdoc at University of British Columbia he moved to University of New Mexico, Albuquerque, where he stayed for many years as a professor of physics and astronomy.  He is a member of American Astronomical Society and Canadian Astronomical Society.  He has co-authored over 100 scientific papers.  He wrote a textbook "Advanced Astrophysics" published by Cambridge University Press in 2003.

Isabel Martin Lewis: Isabel Martin Lewis (July 11, 1881 – July 31, 1966) was an American astronomer who was the first woman hired by the United States Naval Observatory as assistant astronomer.  In 1918, Lewis was elected a member of the American Astronomical Society.  She was also a member of the Royal Astronomical Society of Canada and the Astronomical Society of the Pacific.

Bulletin of the American Astronomical Society: Bulletin of the American Astronomical Society ("BAAS"; "Bull.  Am.  Astron.  Soc.")  is the journal of record for the American Astronomical Society established in 1969.  It publishes meetings of the society, obituaries of its members, and scholarly articles.  Four issues are published per year that are collected into a single volume.

Supporting paragraphs: Isabel Martin Lewis United States Naval Observatory
Answer: 1918