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OSCAR

 
Computer Desktop Encyclopedia: OSCAR
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(Open System for CommunicAtion in Realtime) AOL's internal project name for AOL Instant Messenger (AIM). The core functions of OSCAR, known as the Basic OSCAR Services (BOS), include Login/Logoff, Locate (find out about other AIM users), Instant Message (send message) and Buddy List management. In 1998, AOL introduced TOC, a subset of OSCAR released under the GNU license, which has been used to write AIM clients for Linux and other operating systems. See FLAP.

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Wikipedia: OSCAR
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Home > Library > Miscellaneous > Wikipedia
This article is about the satellite. For other uses, see Oscar (disambiguation).
OSCAR 1

OSCAR is an acronym for Orbiting Satellite Carrying Amateur Radio. OSCAR series satellites use amateur radio frequencies to communicate with amateur radio stations. They are conceived, designed, and built by amateur radio operators under the general direction of national organisations such as AMSAT.

Contents

Early OSCAR satellites

USSR postal stamp depicting amateur radio satellite

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. 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.

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.

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.
Designator
H
A
V
U
L
S
S2
C
X
K
R
Band 15 m 10 m 2 m 70 cm 23 cm 13 cm 9 cm 5 cm 3 cm 1.2 cm 6 mm
Frequency
(General)		 21 MHz 29 MHz 145 MHz 435 MHz 1.2 GHz 2.4 GHz 3.4 GHz 5 GHz 10 GHz 24 GHz 47 GHz

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
\Delta f=\frac{fv}{C}
f_d=f+\frac{fv}{C}
f_u=f-\frac{fv}{C}

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.

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) Decayed; 1961-12-12 USA
OSCAR II (OSCAR 2) Decayed; 1962-06-02 USA
OSCAR III (OSCAR 3, EGRS-3) Non-Operational; 1965-03-09 USA
OSCAR IV (OSCAR 4) Decayed; 1965-12-21 USA
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 USA
AMSAT-OSCAR 7 (OSCAR 7, AO-7, AO-B, P2B) Semi-Operational; 1974-11-15 USA / Spain
AMSAT-OSCAR 8 (OSCAR 8, AO-8, AO-D, P2D) Non-Operational; 1978-03-05 USA
UoSat-OSCAR 9 (UOSAT 1, UO-9) Decayed; 1981-10-06 UK
AMSAT-OSCAR 10 (Phase 3B, AO-10, P3B) Non-Operational; 1983-06-16 USA
UoSat-OSCAR 11 (UoSat-2, UO-11, UoSAT-B) Semi-Operational; 1984-03-01 UK
Fuji-OSCAR 12 (JAS 1, FO-12) Non-Operational; 1986-08-13 Japan
AMSAT-OSCAR 13 (Phase 3C, AO-13, P3C) Decayed; 1988-06-15 USA
UOSAT-OSCAR 14 (UoSAT-3, UO-14 UoSAT-D) Non-Operational; 1990-01-21 UK
UOSAT-OSCAR 15 (UoSAT-4, UO-15, UoSAT-E) Non-Operational; 1990-01-22 UK
AMSAT-OSCAR 16 (Pacsat, AO-16, Microsat-1) Non-Operational; 1990-01-22 USA
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 USA
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 Non-Operational; 1991-02-05 Russia
Radio Sputnik 13 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
Arasene-OSCAR 24 (Arasene, 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) Semi-Operational; 1993-09-26 Italy
AMRAD-OSCAR 27 (EYESAT-1, AO-27) Operational; 1993-09-26 USA
POSAT-OSCAR 28 (POSAT, PO-28, Posat-1) Non-Operational; 1993-09-26 Portugal
Radio Sputnik 15 (RadioSkaf-15, RS-15, Radio-ROSTO) Non-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) Operational; 1998-07-10 Israel
SEDSat-OSCAR 33 (SEDSat, SO-33, SEDsat-1) Semi-Operational; 1998-10-24 USA
Pansat-OSCAR 34 (PAN SAT, PO-34) Non-Operational; 1998-10-30 USA
Sunsat-OSCAR 35 (SUNSAT, SO-35) Non-Operational; 1999-02-23 South Africa
ARISS (ARISS) Operational; International
ASU-OSCAR 37 (AO-37, ASUsat-1, ASUSAT) Non-Operational; 2000-01-27 USA
OPAL-OSCAR 38 (OO-38, StenSat, OPAL) Non-Operational; 2000-01-27 USA
Weber-OSCAR 39 (WO-39, JAWSAT) Non-Operational; 2000-01-27 USA
Saudi-OSCAR 41 (SO-41, Saudisat 1A) Non-Operational; 2000-01-27 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 USA
Starshine-OSCAR 43 (SO-43, Starshine 3) Decayed; 2001-09-30 USA
Navy-OSCAR 44 (NO-44, PCSat) Semi-Operational; 2001-09-30 USA
Navy-OSCAR 45 (NO-45, Sapphire) Non-Operational; 2001-09-30 USA
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
CanX-1 Decayed; 2003-06-30 Canada
DTUSat Decayed; 2003-06-30 Denmark
AAU Cubesat Non-Operational; 2003-06-30 Denmark
AMSAT-OSCAR 51 (Echo, AO-51) Operational; 2004-06-28 USA
RS-22 (Mozhayets 4) Operational; 2004-09-27 Russia
VUSat-OSCAR 52 (Hamsat, VO-52, VUSat) Operational; 2005-05-05 India / Netherlands
PCSat2 (PCSAT2) Decayed; 2005-08-03 USA
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
UWE-1 Non-Operational; 2005-10-27 Germany
NCube-2 Non-Operational; 2005-10-27 Norway
CubeSat-OSCAR 56 (CO-56, Cute-1.7) Semi-Operational; 2006-02-21 Japan
K7RR-Sat Non-Operational; 2006-07-26 USA
CP2 Non-Operational; 2006-07-26 USA
HAUSAT 1 Non-Operational; 2006-07-26 South Korea
ICE Cube 1 Non-Operational; 2006-07-26 USA
ICE Cube 2 Non-Operational; 2006-07-26 USA
ION Non-Operational; 2006-07-26 USA
KUTESat Non-Operational; 2006-07-26 USA
MEROPE Non-Operational; 2006-07-26 USA
nCUBE 1 Non-Operational; 2006-07-26
RINCON Non-Operational; 2006-07-26 USA
SACRED Non-Operational; 2006-07-26 USA
SEEDS Non-Operational; 2006-07-26 Japan
Voyager Non-Operational; 2006-07-26 USA
PicPot Non-Operational; 2006-07-26 Italy
Libertad-1 Operational; 2006-09-15 Colombia
CAPE-1 Non-Operational; 2006-09-15 USA
CP3 Operational; 2006-09-30 USA
Delfi-C3 (DO-64) Operational; 2008-04-28 Netherlands
SumbandilaSat-OSCAR 67 (SumbandilaSat, SO-67) Operational; 2009-09-17 South Africa

Multinational effort

Currently 23 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, Pakistan, Russia, France, Portugal, Korea, Italy, Mexico, Israel, Thailand, South Africa, Malaysia, Saudi Arabia, Germany, India, Colombia, and the Netherlands.

Satellites in development

Related names

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).

References

External links


This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

 
 
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