OSCAR
From Wikipedia, the free encyclopedia
OSCAR is an acronym for Orbiting Satellite Carrying Amateur Radio.
OSCAR series satellites use amateur radio frequencies to communicate with earth. They are conceived, designed, and built by amateur radio operators under the general direction of national organisations such as AMSAT.
Contents |
[edit] The beginning
The first amateur satellite simply named OSCAR-1 , was launched on December 12, 1961, barely four years after the launch of Russia's first satellite, Sputnik. OSCAR-1 was the very first satellite to be ejected as a secondary payload and subsequently enter a separate orbit. Despite being in orbit only 22 days OSCAR-1 was an immediate success with over 570 amateur radio operators in 28 countries forwarding observations to Project OSCAR. Throughout the years OSCAR satellites have helped make significant breakthroughs in the science of satellite communications. A few advancements include the launch of the very first satellite voice transponders and the development of highly advanced digital "store-and-forward" messaging transponder techniques. To-date over 70 OSCAR's have been launched with more to be launched in the near future.
[edit] OSCAR Satellite Communications
Currently OSCAR satellites support many different types of operation including FM voice, SSB voice, as well as digital communications of AX.25 FSK (Packet radio) and PSK-31.
[edit] Mode Designators
- Historically OSCAR uplink (transmit to) and downlink (receive from) frequencies were designated using single letter codes.
- New 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.
[edit] Doppler shift
Due to the high orbital speed of OSCAR 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.
| Where: | ||
|---|---|---|
| fd | = | doppler corrected downlink frequency |
| fu | = | doppler corrected uplink frequency |
| f | = | original frequency |
| v | = | velocity of the satellite relative to ground station in m/s. Positive when moving towards, negative when moving away. |
| C | = | the speed of light in a vacuum (3x108 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 correction. Manual doppler correction is possible, however it is difficult to remain exactly on frequency. FM is more tolerant of doppler shift than SSB and therefore much easier to tune manually.
[edit] Satellites previously launched
The names of the satellites below are sorted in chronological order by launch date, acsending. 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.
-
Name (a.k.a) Status Launched Country OSCAR (OSCAR 1) 1961-12-12 USA OSCAR II (OSCAR 2) 1962-06-02 USA OSCAR III (OSCAR 3, EGRS-3) 1965-03-09 USA OSCAR IV (OSCAR 4) 1965-12-21 USA Australis-OSCAR 5 (OSCAR 5, AO-5, AO-A) 1970-01-23 Australia AMSAT-OSCAR 6 (OSCAR 6, AO-6, AO-C, P2A) 1972-10-15 USA AMSAT-OSCAR 7 (OSCAR 7, AO-7, AO-B, P2B) 1974-11-15 USA / Spain AMSAT-OSCAR 8 (OSCAR 8, AO-8, AO-D, P2D) 1978-03-05 USA UoSat-OSCAR 9 (UOSAT 1, UO-9) 1981-10-06 UK AMSAT-OSCAR 10 (Phase 3B, P3B) 1983-06-16 USA UoSat-OSCAR 11 (UoSat-2, UO-11, UoSAT-B) 1984-03-01 UK Fuji-OSCAR 12 (JAS 1, FO-12) 1986-08-13 Japan AMSAT-OSCAR 13 (Phase 3C, AO-13, P3C) 1988-06-15 USA UOSAT-OSCAR 14 (UoSAT-3, UO-14 UoSAT-D) 1990-01-21 UK UOSAT-OSCAR 15 (UoSAT-4, UO-15, UoSAT-E) 1990-01-22 UK AMSAT-OSCAR 16 (Pacsat, AO-16, Microsat-1) 1990-01-22 USA Dove-OSCAR 17 (Dove, DO-17, Microsat-2) 1990-01-22 Brazil Weber-OSCAR 18 (WeberSAT, WO-18, Microsat-3) 1990-01-22 USA LUSAT-OSCAR 19 (LUSAT, LO-4, Microsat-4) 1990-01-22 Argentina Fuji-OSCAR 20 (JAS 1B, FO-20, Fuji-1B) 1990-02-07 Japan AMSAT-OSCAR 21 (RS-14, AO-21, Informator-1) 1991-01-29 Russia Radio Sputnik 12 1991-02-05 Russia Radio Sputnik 13 1991-02-05 Russia UoSat-OSCAR 22 (UOSAT 5, UO-22 UoSAT-F) 1991-07-17 UK KitSAT-OSCAR 23 (KITSAT 1, KO-23, Uribyol-1) 1992-08-10 Korea Arasene-OSCAR 24 (Arasene, AO-24) 1993-05-12 France AMRAD-OSCAR 27 (EYESAT-1, AO-27) 1993-09-26 USA KitSAT-OSCAR 25 (KITSAT B, KO-25, Kitsat-2, Uribyol-2) 1993-09-26 Korea POSAT-OSCAR 28 (POSAT, Posat-1) 1993-09-26 Portugal Italy-OSCAR 26 (ITAMSAT, IO-26) 1993-09-26 Italy Radio Sputnik 15 (RadioSkaf-15, RS-15, Radio-ROSTO) 1994-12-26 Russia Fuji-OSCAR 29 (JAS 2, FO-29, Fuji-2) 1996-08-17 Japan Mexico-OSCAR 30 (UNAMSAT-2, MO-30, Unamsat-B, Kosmos-2334) 1996-09-05 Mexico/Russia Gurwin-OSCAR 32 (GO-32, Gurwin-1b, Techsat-1b) 1998-07-10 Israel Thai-Microsatellite-OSCAR 31 (TMSAT-1, TO-31) 1998-07-10 Thailand SEDSat-OSCAR 33 (SEDSat, SO-33, SEDsat-1) 1998-10-24 USA Pansat-OSCAR 34 (PAN SAT, PO-34) 1998-10-30 USA ARISS (ARISS) International ASU-OSCAR 37 (AO-37, ASUsat-1, ASUSAT) 2000-01-27 USA OPAL-OSCAR 38 (OO-38, StenSat, OPAL) 2000-01-27 USA Weber-OSCAR 39 (WO-39, JAWSAT) 2000-01-27 USA Saudi-OSCAR 41 (SO-41, Saudisat 1A) 2000-01-27 Saudi Arabia Malaysian-OSCAR 46 (MO-46, TIUNGSAT-1) 2000-09-26 Malaysia Saudi-OSCAR 42 (SO-42, Saudisat 1B) 2000-09-26 Saudi Arabia AMSAT-OSCAR 40 (AO-40, Phase 3D, P3D) 2000-11-16 USA Navy-OSCAR 44 (NO-44, PCSat) 2001-09-30 USA Starshine-OSCAR 43 (SO-43, Starshine 3) 2001-09-30 USA Navy-OSCAR 45 (NO-45, Sapphire) 2001-09-30 USA BreizhSAT-OSCAR 47 (BO-47, IDEFIX CU1) 2002-05-04 France BreizhSAT-OSCAR 48 (BO-48, IDEFIX CU2) 2002-05-04 France Saudi-OSCAR 50 (SO-50, Saudisat-1C) 2002-12-20 Saudi Arabia AATiS-OSCAR 49 (AO-49, Safir-M, RUBIN 2) 2002-12-20 Germany CubeSat-OSCAR 55 (Cute-1) 2003-06-30 Japan CubeSat-OSCAR 57 (CubeSat-XI-IV) 2003-06-30 Japan CanX-1 2003-06-30 Canada DTUSat 2003-06-30 Denmark AAU Cubesat 2003-06-30 Denmark AMSAT-OSCAR 51 (Echo) 2004-06-28 USA RS-22 (Mozhayets 4) 2004-09-27 Russia VUSat-OSCAR 52 (Hamsat, VUSat) 2005-05-05 India / Netherlands PCSat2 (PCSAT2) 2005-08-03 USA AMSAT-OSCAR 54 (AO-54, SuitSat, Radioskaf) 2005-09-08 International eXpress-OSCAR 53 (XO-53, SSETI Express) 2005-10-27 ESA CubeSat-OSCAR 58 (CO-58, Cubesat XI-V) 2005-10-27 Japan UWE-1 2005-10-27 Germany NCube-2 2005-10-27 Norway CubeSat-OSCAR 56 (CO-56, Cute-1.7) 2006-02-21 Japan K7RR-Sat 2006-07-26 USA CP2 2006-07-26 USA HAUSAT 1 2006-07-26 South Korea ICE Cube 1 2006-07-26 USA ICE Cube 2 2006-07-26 USA ION 2006-07-26 USA KUTESat 2006-07-26 USA MEROPE 2006-07-26 USA nCUBE 1 2006-07-26 RINCON 2006-07-26 USA SACRED 2006-07-26 USA SEEDS 2006-07-26 Japan Voyager 2006-07-26 USA PicPot 2006-07-26 Italy Libertad-1 2006-09-15 Colombia CAPE-1 2006-09-15 USA CP3 2006-09-30 USA
[edit] Multinational effort
Currently 21 countries have launched an OSCAR satellite. These countries, in chronological order by date of launch, include: The United States of America, Australia, Spain, the United Kingdom, Japan, Brazil, Argentina, Russia, France, Portugal, Korea, Italy, Mexico, Israel, Thailand, South Africa, Malaysia, Saudi Arabia, Germany, India, & Colombia.
[edit] Satellites in development
- BLUEsat - A microsatellite built by the students of The University of New South Wales. Unknown launch date.
- Prism - A nanosatellite built by the University of Tokyo. Unknown launch date.
- ZSAT - A microsatellite initiated and funded by the U.S. Department of Science and Technology. Unknown launch date.
- ALMASat - A microsatellite built by the University of Bologna in Forlì. Unknown launch date.
- KiwiSAT - A microsatellite built by AMSAT-ZL. Scheduled to launch on June 15 2008
- ESEO - A microsatellite built by SSETI. Scheduled to launch October 30 2008.
[edit] Trivia
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).
[edit] References
- Space Satellites from the World's Garage -- The Story of AMSAT. The Radio Amateur Satellite Corporation. Retrieved on 2006-09-05.
- The Extraordinary History of Amateur Radio Satellites. Space Today Online. Retrieved on 2006-09-05.
- A Brief History of Amateur Satellites. N7HPR. Retrieved on 2006-09-05.
- Satellite Development Programs. The Radio Amateur Satellite Corporation. Retrieved on 2006-09-05.
- Amateur (ham) Radio Satellites. Colorado State University. Retrieved on 2006-09-07.
[edit] External links
- AMSAT Corporation a nonprofit corporation that coordinates construction and launch of the satellites
- Project OSCAR organization that built "OSCAR-1"
- NASA J-Track Amateur Track amateur satellites in real-time
- SSTL Builders and operators of the UoSat series satellites
