OSCAR 3

Project OSCAR Inc. was started in 1960 by members of the TRW Radio Club of Redondo Beach, California as well as persons associated with Foothill College to investigate the possibility of putting an amateur satellite in orbit. Project OSCAR was responsible for the construction of the first Amateur Radio Satellites: OSCAR 1,{{cite book|title=Nanosatellites: Space and Ground Technologies, Operations and Economics|page=496|publisher=John Wiley & Sons, Ltd.|date=2020|location=Glasgow |editor=Rogerio Atem de Carvalho |editor2=Jaime Estela |editor3=Martin Langer|isbn=978-1-119-04203-7|oclc=1126347525}} launched from Vandenberg AFB in California on 12 December 1961, which transmitted a “HI” greeting in Morse Code for three weeks,{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1961-034B|title=OSCAR 1|publisher=NASA Space Science Data Coordinated Archive|access-date=26 November 2020}} the similar OSCAR 2, OSCAR 3, and OSCAR 4.

OSCAR 3 was a {{cvt|15|kg}} rectangular-prism-shaped satellite, {{convert|7|x|12|x|17|in|cm|abbr=on}} in dimension. Unlike its predecessors, which could only transmit a morse code "HI" signal through their beacons, OSCAR 3 was a true communications satellite. Equipped with a translator, when the satellite received signals broadcast to it at 144.1 MHz, its translator converted them to 30 MHz for amplification, and then reconverted them to 145.9 MHz for further amplification and retransmission. A watt of power was available for transmission; if more than one signal were received simultaneously, they shared the power in proportion to their signal strengths when received. OSCAR 3 also carried a beacon like OSCARs 1 and 2, though of lower power.{{cite magazine|url=https://www.rfcafe.com/references/popular-electronics/oscar-3-space-station-popular-electronics-march-1965.htm|title=Oscar III: Ham Radio's New 2-Meter Space Station|date=March 1965|magazine=Popular Electronics|author1=Robert N. Tellefsen|author2=Harley C. Gabrielson|volume=22|number=3|publisher=Ziff-Davis Publishing Co.}}

Four quarter-wave antennas (two for input/output to the translator, one for the beacon, and one for telemetry to the ground) were mounted on the sides of the lightweight magnesium-lithium alloy satellite. The hull was covered with shiny aluminum foil tape to reflect the heat of the Sun, and black stripes were painted over the shiny aluminum to radiate heat away from OSCAR 3 during the times it orbited in the shadow of the Earth. A large 18-volt battery powered the satellite, though the beacon was designed to continue functioning, supplied by power from solar cells and a rechargeable battery.

File:650309nrlcomposite 5.jpg

OSCAR 3 flew on the NRL Composite 5 mission, which lofted an unprecedented{{cite web|url=https://history.nasa.gov/AAchronologies/1965.pdf|title=Aeronautics and Astronautics, 1965|publisher=NASA|access-date=January 2, 2019}} eight satellites on a single Thor Augmented Delta-Agena D rocket (including POPPY 4, an electronic signals intelligence (ELINT) surveillance package, GGSE-2, GGSE-3, Surcal 2B, SECOR 3, SOLRAD 7B, and Dodedcapole 1) on 9 March 1965 from Vandenberg Air Force Base Space Launch Complex 1, Pad 2.{{Cite web|url=https://planet4589.org/space/nro/poppy/NRLC5.html|title=Launch 1965-016: NRL Composite 5|last=McDowell|first=Jonathan|publisher=Jonathon's Space Report|access-date=March 1, 2020}}{{Cite web|url=http://planet4589.org/space/log/launchlog.txt|title=Launch Log|last=McDowell|first=Jonathan|access-date=2018-12-30}}

Though the satellite's active life was limited to sixteen days due to battery failure,{{cite book|author=William R. Corliss|title=Scientific Satellites|publisher=Science and Technical Information Division, Office of Technology Utilization, NASA|date=1967|location=Washington D.C.|pages=765|url=https://archive.org/details/scientificsatell00corl/page/765/mode/2up|access-date=11 May 2020}} OSCAR 3 relayed 176 messages from 98 stations in North America and Europe during its 274 orbit life-time.{{cite magazine|magazine=QST|date=Dec 1965|pages=84–89|url=https://projectoscar.files.wordpress.com/2008/03/oscar_iii_results.pdf|title=OSCAR 3 Report -- Communications Results|author=H. C. Gabrielson|access-date=16 May 2021}} The two beacon transmitters continued operating for several months.{{cite web |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1965-016F |title=Oscar 3 |publisher=NASA National Space Science Data Center |date=30 June 1977 |access-date=15 February 2013}}{{cite web |url=http://space.skyrocket.de/doc_sdat/oscar-3.htm |title=OSCAR 3|publisher=Gunter's Space Page |date=31 December 1999 |access-date=15 February 2013 }} OSCAR 3 was thus the first amateur communications satellite to relay voice contacts in the VHF 2 meter band, the first amateur satellite to operate from solar power and relay signals from Earth, and the first satellite to use beacon transmitters separate from the main communications system.{{cite web |url=http://www.amsat.org/amsat-new/AboutAmsat/amsat_history.php |title=Space Satellites from the World's Garage -- The Story of AMSAT |last1=Baker |first1=Keith |last2=Jansson |first2=Dick |date=23 May 1994 |access-date=15 February 2013 |url-status=dead |archive-url=https://web.archive.org/web/20061005160332/http://www.amsat.org/amsat-new/AboutAmsat/amsat_history.php |archive-date=5 October 2006 }}

{{As of|2023}}, OSCAR 3 is still in orbit, and its position can be tracked online.{{cite web|url=https://www.n2yo.com/satellite/?s=1293|title=OSCAR 3|access-date=16 May 2021}}

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{{Orbital launches in 1965}}

{{OSCAR satellites}}

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Category:Satellites orbiting Earth

Category:Amateur radio satellites

Category:Spacecraft launched in 1965