Amateur radio satellite
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An amateur radio satellite is an artificial satellite built and used by amateur radio operators for use in the Amateur-satellite service. These satellites use amateur radio frequency allocations to facilitate communication between amateur radio stations.
Many amateur-satellites receive an OSCAR designation, which is an acronym for Orbiting Satellite Carrying Amateur Radio. The designation is assigned by AMSAT, an organization which promotes the development and launch of amateur radio satellites. Because of the prevalence of this designation, amateur radio satellites are often referred to as OSCARs.
These satellites can be used for free by licensed amateur radio operators for voice (FM, SSB) and data communications (AX.25, packet radio, APRS). Currently, over 5 fully operational amateur-satellites in orbit act as repeaters, linear transponders or store and forward digital relays.
Throughout the years, amateur-satellites have helped make breakthroughs in the science of satellite communications. A few advancements include the launch of the first satellite voice transponder (OSCAR 3) and the development of highly advanced digital "store-and-forward" messaging transponder techniques.
- 1 History
- 2 Hardware
- 3 Orbits
- 4 Operations
- 5 Launches
- 6 Facts
- 7 References
- 8 Notes
- 9 External links
The first amateur satellite, simply named OSCAR 1, was launched on December 12, 1961, barely four years after the launch of world's first satellite, Sputnik I. The beginning of this project was very humble. The satellite had to be built in a very specific shape and weight, so it could be used in place of one of the weights necessary for balancing the payload in the rocket stage. OSCAR 1 was the first satellite to be ejected as a secondary payload (with Discoverer 36 as the primary) and subsequently enter a separate orbit. The satellite carried no on-board propulsion and the orbit decayed quickly. Despite being in orbit for only 22 days, OSCAR 1 was an immediate success with over 570 amateur radio operators in 28 countries forwarding observations to Project OSCAR.
Most of the components for OSCAR 10 were "off the shelf" and tested by group members. Jan King led the project. Solar cells were bought in batches of 10 or 20 from Radio Shack and tested for efficiency by group members. The most efficient cells were kept for the project, the rest were returned to RadioShack. Once ready, OSCAR 10 was mounted aboard a private plane and flown on a couple of occasions to evaluate its performance and reliability. Special QSL cards were issued to those who participated in the airplane based flights. Once it was found to be operative and reliable, the satellite was shipped to Kennedy Space Center where it was mounted in the third stage of the launch vehicle.
Other programs besides OSCAR have included Iskra (Soviet Union) circa 1982, JAS-1 (Fuji-OSCAR 12) (Japan) in 1986, RS (Soviet Union and Russia), and CubeSats. (There is a list of major amateur satellites in Japanese Wikipedia).
The first amateur satellites contained telemetry beacons. Since 1965, most OSCARs carry a linear transponder for two-way communications in real time. Some satellites have a bulletin board for store-and-forward digital communications, or a digipeater for direct packet radio connections.
Uplink and downlink designations use sets of paired letters following the structure X/Y where X is the uplink band and Y is the downlink band. Occasionally, the downlink letter is rendered in lower case (i.e., X/y). With a few exceptions, the letters correspond to IEEE's standard for radar frequency letter bands
Prior to the launch of OSCAR 40, operating modes were designated using single letters to indicate both uplink and downlink bands. While deprecated, these older mode designations are still widely used in casual conversation.
Due to the high orbital speed of the amateur-satellites, the uplink and downlink frequencies will vary during the course of a satellite pass. This phenomenon is known as the Doppler effect. While the satellite is moving towards the ground station, the downlink frequency will appear to be higher than normal and therefore, the receiver frequency at the ground station must be adjusted higher in order to continue receiving the satellite. The satellite in turn, will be receiving the uplink signal at a higher frequency than normal so the ground station's transmitted uplink frequency must be lower in order to be received by the satellite. After the satellite passes overhead and begins to move away, this process reverses itself. The downlink frequency will appear lower and the uplink frequency will need to be adjusted higher. The following mathematical formulas relate the doppler shift to the velocity of the satellite.
|=||doppler corrected downlink frequency|
|=||doppler corrected uplink frequency|
|=||velocity of the satellite relative to ground station in m/s.
Positive when moving towards, negative when moving away.
|=||the speed of light in a vacuum ( m/s).|
|Change in frequency||Downlink Correction||Uplink Correction|
Due to the complexity of finding the relative velocity of the satellite and the speed with which these corrections must be made, these calculations are normally accomplished using satellite tracking software. Many modern transceivers include a computer interface that allows for automatic doppler effect correction. Manual frequency-shift correction is possible, but it is difficult to remain precisely near the frequency. Frequency modulation is more tolerant of doppler shifts than single-sideband, and therefore FM is much easier to tune manually.
A number of low earth orbit (LEO) OSCAR satellites use frequency modulation (FM). These are also commonly referred to as "FM LEOs" or the "FM Birds". Such satellites act as FM amateur radio repeaters that can be communicated through using omni-directional antennas and commonly available amateur radio equipment. Due to the relative ease of tuning FM as compared to SSB and the decreased distance of LEO satellites from earth stations communication can be achieved even with handheld transceivers and using manual doppler correction. The orbit of these satellites however causes the available time in which to communicate to be limited to only a few minutes per pass.
|Uplink (MHz)||Downlink (MHz)||CTCSS (Hz)||Status|
|Hope Oscar 68||HO-68||145.825 FM||435.675 FM||67.0||Beacon only|
|Sumbandila Oscar 671||SO-67||145.875 FM||435.345 FM||N/A||Lost|
|AMSAT-OSCAR 512||AO-51||145.880 FM||435.150 FM||N/A||Lost|
|145.920 FM||435.300 FM||67.0|
|145.880 FM||2401.200 FM||N/A|
|1268.700 FM||435.300 FM||67.0|
|1268.700 FM||2401.200 FM||67.0|
|Saudi-OSCAR 50||SO-50||145.850 FM||436.795 FM||67.0
(74.4 to activate)
|Saudi-OSCAR 41||SO-41||145.850 FM||436.775 FM||N/A||Lost|
|SUNSAT-OSCAR 35||SO-35||145.825 FM||436.250 FM||N/A||Lost|
|436.291 FM||145.825 FM|
|1265.000 FM||436.2500 FM|
|TechSat 1b-OSCAR 32||SO-32||145.850/145.890/145.930 FM
|ISS3||ARISS||437.800 FM||145.800 FM||N/A||Active|
|AMRAD-OSCAR 274||AO-27||145.850 FM||436.795 FM||N/A||Interference over USA|
|AMSAT-OSCAR 16||AO-16||145.920 FM||437.026 DSB-SC5||N/A||Lost|
|UoSAT-OSCAR 14||UO-14||145.975 FM||435.070 FM||N/A||Lost|
|LituanicaSAT-OSCAR 78 ||LO-78||145.950 FM||435.1755 FM||67.0||Lost|
|European-OSCAR 806||EO-80||435.080 FM||145.840 FM||210.7||Beacon only|
|Note 1: SO-67 suffered[when?] a power board failure. The team hoped (2012) recovery to amateur radio operations was possible.
Note 2: As of November 29, 2011 AO-51 has ceased all transmissions.
Note 3: The ISS FM repeater is rarely activated.
Note 4: New bootloader and OS for AO-27 was successfully written and installed by the team. Satellite experiences interference during uplink while above US
Note 6: EO-80 is currently[when?] completing a science mission and the FM transponder will be activated upon completion of that mission.
The names of the satellites below are sorted in chronological order by launch date, ascending. The status column denotes the current operational status of the satellite. Green signifies that the satellite is currently operational, orange indicates that the satellite is partially operational or failing. Red indicates that the satellite is non operational and black indicates that the satellite has re-entered the Earth's atmosphere. The country listing denotes the country that constructed the satellite and not the launching country.
|Launches (Past & Current)|
|OSCAR (OSCAR 1)||Decayed||1961-12-12||United States|
|OSCAR II (OSCAR 2)||Decayed||1962-06-02||United States|
|OSCAR III (OSCAR 3, EGRS-3)||Non-Operational||1965-03-09||United States|
|OSCAR IV (OSCAR 4)||Decayed||1965-12-21||United States|
|Australis-OSCAR 5 (OSCAR 5, AO-5, AO-A)||Non-Operational||1970-01-23||Australia|
|AMSAT-OSCAR 6 (OSCAR 6, AO-6, AO-C, P2A)||Non-Operational||1972-10-15||United States|
|AMSAT-OSCAR 7 (OSCAR 7, AO-7, AO-B, P2B)||Semi-Operational||1974-11-15||United States|
|AMSAT-OSCAR 8 (OSCAR 8, AO-8, AO-D, P2D)||Non-Operational||1978-03-05||United States/Canada/Germany/Japan|
|Radio Sputnik 1 (RadioSkaf-1, RS-1)||Non-Operational||1978-10-26||USSR|
|Radio Sputnik 2 (RadioSkaf-2, RS-2)||Non-Operational||1978-10-26||USSR|
|UoSat-OSCAR 9 (UOSAT 1, UO-9)||Decayed||1981-10-06||UK|
|Radio Sputniks RS3 through RS8||Non-Operational||1981-12-17||USSR|
|AMSAT-OSCAR 10 (Phase 3B, AO-10, P3B)||Non-Operational||1983-06-16||United States/Germany|
|UoSat-OSCAR 11 (UoSat-2, UO-11, UoSAT-B)||Semi-Operational||1984-03-01||UK|
|Fuji-OSCAR 12 (JAS 1, FO-12)||Non-Operational||1986-08-12||Japan|
|Radio Sputnik 10/11 (RadioSkaf-10/11, RS-10/11, COSMOS 1861)||Non-Operational||1987-06-23||USSR|
|AMSAT-OSCAR 13 (Phase 3C, AO-13, P3C)||Decayed||1988-06-15||Germany|
|UOSAT-OSCAR 14 (UoSAT-3, UO-14 UoSAT-D)||Non-Operational||1990-01-22||UK|
|UOSAT-OSCAR 15 (UoSAT-4, UO-15, UoSAT-E)||Non-Operational||1990-01-22||UK|
|AMSAT-OSCAR 16 (Pacsat, AO-16, Microsat-1)||Semi-Operational||1990-01-22||United States|
|Dove-OSCAR 17 (Dove, DO-17, Microsat-2)||Non-Operational||1990-01-22||Brazil|
|Weber-OSCAR 18 (WeberSAT, WO-18, Microsat-3)||Non-Operational||1990-01-22||United States|
|LUSAT-OSCAR 19 (LUSAT, LO-19, Microsat-4)||Non-Operational||1990-01-22||Argentina|
|Fuji-OSCAR 20 (JAS 1B, FO-20, Fuji-1B)||Non-Operational||1990-02-07||Japan|
|AMSAT-OSCAR 21 (RS-14, AO-21, Informator-1)||Non-Operational||1991-01-29||Russia|
|Radio Sputnik 12/13 (RadioSkaf-12/13, RS-12/13, COSMOS 2123)||Non-Operational||1991-02-05||Russia|
|UoSat-OSCAR 22 (UOSAT 5, UO-22 UoSAT-F)||Non-Operational||1991-07-17||UK|
|KitSAT-OSCAR 23 (KITSAT 1, KO-23, Uribyol-1)||Non-Operational||1992-08-10||Korea|
|Arsene-OSCAR 24 (Arsene, AO-24)||Non-Operational||1993-05-12||France|
|KitSAT-OSCAR 25 (KITSAT B, KO-25, Kitsat-2, Uribyol-2)||Non-Operational||1993-09-26||Korea|
|Italy-OSCAR 26 (ITAMSAT, IO-26)||Non-Operational||1993-09-26||Italy|
|AMRAD-OSCAR 27 (EYESAT-1, AO-27)||Non-Operational||1993-09-26||United States|
|POSAT-OSCAR 28 (POSAT, PO-28, Posat-1)||Non-Operational||1993-09-26||Portugal|
|Radio Sputnik 15 (RadioSkaf-15, RS-15, Radio-ROSTO)||Semi-Operational||1994-12-26||Russia|
|Fuji-OSCAR 29 (JAS 2, FO-29, Fuji-2)||Semi-Operational||1996-08-17||Japan|
|Mexico-OSCAR 30 (UNAMSAT-2, MO-30, Unamsat-B, Kosmos-2334)||Non-Operational||1996-09-05||Mexico/Russia|
|Thai-Microsatellite-OSCAR 31 (TMSAT-1, TO-31)||Non-Operational||1998-07-10||Thailand|
|Gurwin-OSCAR 32 (GO-32, Gurwin-1b, Techsat-1b)||Non-Operational||1998-07-10||Israel|
|SEDSat-OSCAR 33 (SEDSat, SO-33, SEDsat-1)||Semi-Operational||1998-10-24||United States|
|Pansat-OSCAR 34 (PAN SAT, PO-34)||Non-Operational||1998-10-29||United States|
|Sunsat-OSCAR 35 (SUNSAT, SO-35)||Non-Operational||1999-02-23||South Africa|
|UoSat-OSCAR 36 (UOSAT 12, UO-36)||Non-Operational||1999-04-21||UK|
|ASU-OSCAR 37 (AO-37, ASUsat-1, ASUSAT)||Non-Operational||2000-01-27||United States|
|OPAL-OSCAR 38 (OO-38, StenSat, OPAL)||Non-Operational||2000-01-27||United States|
|Weber-OSCAR 39 (WO-39, JAWSAT)||Non-Operational||2000-01-27||United States|
|Saudi-OSCAR 41 (SO-41, Saudisat 1A)||Non-Operational||2000-09-26||Saudi Arabia|
|Saudi-OSCAR 42 (SO-42, Saudisat 1B)||Non-Operational||2000-09-26||Saudi Arabia|
|Malaysian-OSCAR 46 (MO-46, TIUNGSAT-1)||Non-Operational||2000-09-26||Malaysia|
|AMSAT-OSCAR 40 (AO-40, Phase 3D, P3D)||Non-Operational||2000-11-16||United States|
|Starshine-OSCAR 43 (SO-43, Starshine 3)||Decayed||2001-09-30||United States|
|Navy-OSCAR 44 (NO-44, PCSat)||Semi-Operational||2001-09-30||United States|
|Navy-OSCAR 45 (NO-45, Sapphire)||Non-Operational||2001-09-30||United States|
|BreizhSAT-OSCAR 47 (BO-47, IDEFIX CU1)||Non-Operational||2002-05-04||France|
|BreizhSAT-OSCAR 48 (BO-48, IDEFIX CU2)||Non-Operational||2002-05-04||France|
|AATiS-OSCAR 49 (AO-49, Safir-M, RUBIN 2)||Non-Operational||2002-12-20||Germany|
|Saudi-OSCAR 50 (SO-50, Saudisat-1C)||Operational||2002-12-20||Saudi Arabia|
|CubeSat-OSCAR 55 (Cute-1)||Operational||2003-06-30||Japan|
|CubeSat-OSCAR 57 (CubeSat-XI-IV)||Operational||2003-06-30||Japan|
|RS-22 (Mozhayets 4)||Operational||2003-09-27||Russia|
|AMSAT-OSCAR 51 (Echo, AO-51)||Non-Operational||2004-06-28||United States|
|VUSat-OSCAR 52 (HAMSAT, VO-52, VUSat)||Semi-Operational ||2005-05-05||India / Netherlands|
|PCSat2 (PCSAT2)||Decayed||2005-08-03||United States|
|AMSAT-OSCAR 54 (AO-54, SuitSat, Radioskaf)||Decayed||2005-09-08||International|
|eXpress-OSCAR 53 (XO-53, SSETI Express)||Non-Operational||2005-10-27||ESA|
|CubeSat-OSCAR 58 (CO-58, Cubesat XI-V)||Operational||2005-10-27||Japan|
|CubeSat-OSCAR 56 (CO-56, Cute-1.7)||Non-Operational||2006-02-21||Japan|
|HAUSAT 1||Non-Operational||2006-07-26||South Korea|
|ICE Cube 1||Non-Operational||2006-07-26||United States|
|ICE Cube 2||Non-Operational||2006-07-26||United States|
|HITSat-OSCAR 59 (HITSat, HO-59)||Non-Operational||2006-09-22||Japan|
|Navy-OSCAR 60 (RAFT, NO-60)||Decayed||2006-12-21||United States|
|Navy-OSCAR 61 (ANDE, NO-61)||Decayed||2006-12-21||United States|
|Navy-OSCAR 62 (FCAL, NO-62)||Decayed||2006-12-21||United States|
|Pehuensat-OSCAR 63 (PEHUENSAT-1, PO-63)||Decayed||2007-10-01||Argentina|
|Delfi-OSCAR 64 (Delfi-C3, DO-64)||Semi-Operational||2008-04-28||Netherlands|
|Cubesat-OSCAR 65 (Cute-1.7+APD II, CO-65)||Operational||2008-04-28||Japan|
|Cubesat-OSCAR 66 (SEED II, CO-66)||Operational||2008-04-28||Japan|
|PARADIGM (BEVO-1)||Decayed||2009-07-30||United States|
|Sumbandila-OSCAR 67 (SumbandilaSat, SO-67)||Non-Operational||2009-09-17||South Africa|
|Hope Oscar 68 (XW-1, HO-68)||Beacon-Operational||2009-12-15||China|
|AubieSat-1 (AO-71)||Operational||2011-10-28||United States|
|FUNcube-1 (AO-73) ||Operational||2013-11-21||UK|
|This section's factual accuracy may be compromised due to out-of-date information. (November 2010)|
- IRSHSAT-1 - A cubesat is being built by the students at Pakistan Student Satellite Program. Launch Date sometime in 2011.
- BLUEsat - A microsatellite built by the students of The University of New South Wales. Unknown launch date. The next test will be in April 2014 when it is flown from a stratospheric weather balloon.
- ZSAT - A microsatellite initiated and funded by the U.S. Department of Science and Technology[clarification needed]. Unknown launch date.
- AMSAT-Phase 3E - A satellite built by AMSAT. Delayed Indefinitely.
- KiwiSAT - A microsatellite built by AMSAT-ZL. Scheduled to launch from mid to late 2009
- ESEO - A microsatellite built by SSETI. Scheduled to launch in 2015-2016.
- AMSAT-Eagle - A satellite built by AMSAT. Cancelled.
- Delfi-n3Xt - The second nano-satellite from Delft University of Technology. Launched the 21 November 2013.
- Fox-1 - A 1u cubesat from AMSAT-NA. Scheduled to launch in August 2015.
Currently, 23 countries have launched an OSCAR satellite. These countries, in chronological order by date of launch, include: The
SuitSat, an obsolete Russian space suit with a transmitter aboard, is officially known as OSCAR 54. In a twist of fate, "Oscar" was the name given to an obsolete space suit by its young owner in the book Have Space Suit—Will Travel, by Robert A. Heinlein. This book was originally published a year after the launch of the first artificial satellite (Sputnik).
- ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.57, definition: amateur-satellite service / amateur-satellite radiocommunication service
- Standard Radar Frequency Letter-Band Nomenclature (IEEE Standard 521-1984, IEEE Std 521-2002(R2009))
- "OSCAR Number for LituanicaSAT-1".
- "SA AMSAT". Southern African Amateur Radio Satellite Association. Retrieved 2012-08-09.
- "AMSAT AO-51 Control Team News". AO-51 Command Team and Operations Group. Retrieved 2012-01-15.[dead link]
- "ISS Fan Club". ISS Fan Club. Retrieved 2011-07-27.
- "Official AO-27 HomePage". AO-27 Control Operators Association. Retrieved 2013-01-06.
AO-27 Turned on today. Seems good on the bootloader[dead link]
- "2010 AMSAT Field Day Competition" (PDF). The Radio Amateur Satellite Corporation. 2010. p. 1. Retrieved 2011-07-26.
...the FM voice satellites like AMSAT-OSCAR 16, AMRAD-OSCAR-27, SaudiSat-Oscar-50, or AMSAT-OSCAR-51...[dead link]
- "AMSAT OSCAR 16 (PacSAT)". The Radio Amateur Satellite Corporation. Retrieved 2011-07-26.
Mode FM Voice Repeater (Downlink is DSB. Operation is Intermittent)[dead link]
- "VO-52 "Hamsat" end of mission". AMSAT.
- Martin Davidoff: The Radio Amateur’s Satellite Handbook. The American Radio Relay League, Newington, ISBN 978-0-87259-658-0.
- "Space Satellites from the World's Garage -- The Story of AMSAT". The Radio Amateur Satellite Corporation. Retrieved 2006-09-05.
- "The Extraordinary History of Amateur Radio Satellites". Space Today Online. Retrieved 2006-09-05.
- "Satellite Development Programs". The Radio Amateur Satellite Corporation. Retrieved 2006-09-05.
|Wikimedia Commons has media related to Amateur radio satellites.|
- AMSAT Corporation - a nonprofit corporation that coordinates construction and launch of amateur radio satellites
- Project OSCAR - club commemorating the original Project OSCAR group
- NASA J-Track Amateur Site for tracking amateur radio satellites in real-time
- Work-Sat - Private site with instructions for using amateur radio satellites