Question: Who assembled the phonograph records that were included aboard both Voyager spacecraft launched in 1977?
Context: Carl Edward Sagan ( ; November 9, 1934 – December 20, 1996) was an American astronomer, cosmologist, astrophysicist, astrobiologist, author, science popularizer, and science communicator in astronomy and other natural sciences.  He is best known for his work as a science popularizer and communicator.  His best known scientific contribution is research on extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation.  Sagan assembled the first physical messages sent into space: the Pioneer plaque and the Voyager Golden Record, universal messages that could potentially be understood by any extraterrestrial intelligence that might find them.  Sagan argued the now accepted hypothesis that the high surface temperatures of Venus can be attributed to and calculated using the greenhouse effect. Mars 6 (Russian: Марс-6 ), also known as 3MP No.50P was a Soviet spacecraft launched to explore Mars.  A 3MP bus spacecraft launched as part of the Mars programme, it consisted of a lander, and a coast stage with instruments to study Mars as it flew past. The Soviet crewed lunar programs were a series of unsuccessful programs pursued by the Soviet Union to land a man on the Moon, in competition with the United States Apollo program to achieve the same goal set publicly by President John F. Kennedy on May 25, 1961.  The Soviet government publicly denied participating in such a competition, but secretly pursued two programs in the 1960s: crewed lunar flyby missions using Soyuz 7K-L1 (Zond) spacecraft launched with the Proton-K rocket, and a crewed lunar landing using Soyuz 7K-LOK and LK Lander spacecraft launched with the N1 rocket.  Following the dual American successes of the first crewed lunar orbit on December 24–25, 1968 (Apollo 8) and the first Moon landing on July 20, 1969 (Apollo 11), and a series of catastrophic N1 failures, both Soviet programs were eventually brought to an end.  The Proton-based Zond program was canceled in 1970, and the N1 / L3 program was terminated de facto in 1974 and officially canceled in 1976.  Details of both Soviet programs were kept secret until 1990 when the government allowed them to be published under the policy of "glasnost". Soyuz TM-29 was a Russian manned spacecraft launched from the Baikonur Cosmodrome aboard a Soyuz 11A511U rocket.  It docked with Mir on February 22 at 05:36 GMT with Cosmonauts Viktor Afanasyev of Russia, Jean-Pierre Haigneré of France, and Ivan Bella of Slovakia aboard.  Since two crew seats had been sold (to Slovakia and France), Afanasyev was the only Russian cosmonaut aboard.  This meant that Russian engineer Avdeyev already aboard Mir would have to accept a double-length assignment.  After the February 27 departure of EO-26 crew commander Padalka and cosmonaut Bella aboard Soyuz TM-28, the new EO-27 Mir crew consisted of Afanasyev as Commander, Avdeyev as Engineer and French cosmonaut Haigneré. Okeh Records is an American record label founded by the Otto Heinemann Phonograph Corporation, a phonograph supplier established in 1916, which branched out into phonograph records in 1918.  Since 1926, Okeh has been a subsidiary of Columbia Records, now itself a subsidiary of Sony Music.  Today, Okeh is an imprint of Sony Masterworks, a specialty label of Columbia. Voyager 1 is a space probe launched by NASA on September 5, 1977.  Part of the Voyager program to study the outer Solar System, "Voyager 1" launched 16 days after its twin, "Voyager 2".  Having operated for 2017-1977- years, 11-09+ months and  days as of none }} , the spacecraft still communicates with the Deep Space Network to receive routine commands and return data.  At a distance of 140 AU from the Sun as of September 22, 2017, it is the farthest spacecraft from Earth as well as the farthest man-made object.  It is also the most distant object in the solar system whose location is known, even farther than Eris (96 AU) and V774104 (~103 AU). Valya Mladenova Balkanska (Bulgarian: Валя Младенова Балканска ) (born 8 January 1942) is a Bulgarian folk music singer from the Rhodope Mountains known locally for her wide repertoire of Balkan folksong, but in the West mainly for singing the song "Izlel ye Delyo Haydutin", part of the Voyager Golden Record selection of music included in the two Voyager spacecraft launched in 1977. The Voyager Golden Records are phonograph records that were included aboard both Voyager spacecraft launched in 1977.  The records contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form, or for future humans, who may find them.  Those records are considered as a sort of a time capsule. Cosmic Ray Subsystem (CRS, or Cosmic Ray System) is an instrument aboard the "Voyager 1" and "Voyager 2" spacecraft of the NASA Voyager program, and it is an experiment to detect cosmic rays.  The CRS includes a High-Energy Telescope System (HETS), Low-Energy Telescope System (LETS), and The Electron Telescope (TET).  It is designed to detect energetic particles and some the requirements were for the instrument to be reliable and to have enough charge resolution.  It can also detect the energetic particles like protons from the Galaxy or Earth's Sun.  As of 2017, CRS is one of the active remaining instruments on both Voyager spacecraft, and it is described by as being able to detect electrons from 3-110 MeV and cosmic ray nuclei 1-500 MeV/n.  All three systems used solid-state detectors.  CRS is one of the five fields and particle experiments on each spacecraft, and one of the goals is to gain a deeper understanding of the solar wind.  Other objects of study including electrons and nuclei from planetary magnetospheres and from outside the solar system. The United States Phonograph Company was a manufacturer of cylinder phonograph records and supplies in the 1890s.  It was formed in the Spring of 1893 by Victor Emerson, manager of the New Jersey Phonograph Company.  Simon S. Ott and George E. Tewkesbury, heads of the Kansas Phonograph Company and inventors of an automatic phonograph joined later.  It was based in Newark, New Jersey.  After the collapse of the North American Phonograph Company in August 1894, the United States Phonograph Company became one of the industry's largest suppliers of records, competing mostly with the Columbia Phonograph Company who had joined with the American Graphophone Company to manufacture graphophones (at this point nearly identical to phonographs), blank wax cylinders, and original and duplicate records.  The USPC manufactured duplicates as well, which allowed their recording program to reach the scale of competing with Columbia's.  Their central location and proximity to New York allowed them to record the most popular artists of the 1890s, including George J. Gaskin, Dan W. Quinn, Len Spencer, Russell Hunting and Issler's Orchestra.  Emerson left the company to lead Columbia's recording department around the summer of 1896.  In 1897 the USPC worked with Edison's National Phonograph Company to retrofit phonographs with spring motors invented by Frank Capps.  The convenience and cost savings of spring-motor phonographs like these helped shift the phonograph from a public entertainment (in parlors or exhibitions) to a consumer good.  In October 1899 the company was prohibited by court order from manufacturing duplicate records, and they began supplying original records for the National Phonograph Company[7][6]<nowiki>[5]</nowiki>.  The later U.S. Phonograph Company of Cleveland Ohio is unrelated.
Answer: Carl Edward Sagan