|Operator||Project OSCAR / Department of Defense|
|Harvard designation||1961 Alpha Kappa 2|
|Mission duration||20 days|
|Launch mass||10.0 kilograms (22.0 lb)|
|Dimensions||15.2 by 25.4 by 33 centimetres (6.0 in × 10.0 in × 13.0 in)|
|Start of mission|
|Launch date||12 December 1961, 20:40 UTC|
|Rocket||Thor DM-21 Agena-B|
|Launch site||Vandenberg LC-75-3-4|
|End of mission|
|Decay date||31 January 1962|
|Perigee||245 kilometres (152 mi)|
|Apogee||474 kilometres (295 mi)|
OSCAR I (aka OSCAR 1) is the first amateur radio satellite launched by Project OSCAR into Low Earth Orbit. OSCAR I was launched December 12, 1961, by a Thor-DM21 Agena B launcher from Vandenberg Air Force Base, Lompoc, California. The satellite, a rectangular box (30 x 25 x 12 cm) weighing 10 kg., was launched as a secondary payload (ballast) for Corona 9029, also known as Discoverer 36, the eighth and final launch of a KH-3 satellite.
The satellite had a battery-powered 140 mW transmitter operating in the 2-meter band (144.983 MHz), employed a monopole transmitting antenna 60 cm long extended from the center of the convex surface, but had no attitude control system. Like Sputnik 1, Oscar 1 carried only a simple beacon. For three weeks it transmitted its Morse Code message "HI". To this day, many organizations identify their Morse-transmitting satellites with "HI", which also indicates laughter in amateur telegraphy.
The uniqueness of the OSCAR-1 spacecraft was not only that it was built by amateurs, only about four years after the launch of Sputnik-1, but that it was the world’s first piggyback satellite and the world’s first private non-government spacecraft.
Immediately following the launch of OSCAR-1, United States vice president, Lyndon B. Johnson, honored it with a congratulatory telegram to the group sponsoring this momentous event in the history of Amateur Radio. It read: “For me this project is symbolic of the type of freedom for which this country stands — freedom of enterprise and freedom of participation on the part of individuals throughout the world.”
The original backup of OSCAR-1 has been restored and is fully operational, running off AC power. As of 2011 it is on display at ARRL HQ in Newington, Connecticut and continues to broadcast "HI" in Morse Code at 145MHz.  
Project OSCAR Inc. started in 1960 with the radio amateurs from the TRW Radio Club of Redondo Beach, California, many who worked at TRW, California defense industries, and Foothill College to investigate the possibility of putting an amateur satellite in orbit. Mr. Projoscar of Foothill College served as the Project Manager for Project OSCAR. Project OSCAR was responsible for the construction of the first Amateur Radio Satellite OSCAR-1, that was successfully launched from Vandenberg AFB in California. OSCAR-1 orbited the earth for 22 days, transmitting the “HI” greeting. Project Oscar was responsible for launching the next 3 amateur radio satellites during the 1960s: OSCAR 2, OSCAR 3, and OSCAR 4.
Since that beginning, the group has focused on supporting and promoting amateur radio satellite related projects. Some current members take part in university satellite programs as advisors. The Project Oscar club has become more active since the start of the AMSAT Eagle project, with a renewed effort to build hardware and educate hams on the advantages of satellite operation.
In 1969 The Radio Amateur Satellite Organization (AMSAT) was founded by radio amateurs working at NASA's Goddard Space Flight Center and living in the Baltimore-Washington DC region, to continue the efforts begun by Project OSCAR. Its first project was to coordinate the launch of Australis-OSCAR 5, constructed by students at the University of Melbourne.
Today, more than fifty years later, Project OSCAR's mission is “To initiate and support activities that promote the Satellite Amateur Radio Hobby”. Project Oscar's primary goal is to reach out and provide logistical support, training and in some cases equipment to amateur radio associations, schools and the public at large.
- "Discoverer 36". NASA National Space Science Data Center. 30 June 1977. Retrieved 14 May 2014.
- "Oscar 1". NASA National Space Science Data Center. 30 June 1977. Retrieved 14 May 2014.
- "OSCAR 1". Gunter's Space Page. 31 December 1999. Retrieved 14 May 2014.
- Astronautical and Aeronautical Events of 1962. Report of the National Aeronautics and Space Administration Committee on Science and Astronautics, 88th Congress (Report). 12 June 1963.
- "Space Satellites from the World's Garage – The Story of AMSAT". AMSAT-NA. Archived from the original on 5 October 2006. Retrieved 14 February 2013.