Amateur radio satellite
The designation is assigned by AMSAT, an organization which promotes the development and launch of amateur radio satellites.
[2] They may be designed to act as repeaters, as linear transponders, and as store and forward digital relays.
AMSAT has not been actively involved in the launch and operation of most amateur satellites in the last two decades beyond allocating an OSCAR number.
Over 570 amateur radio operators in 28 countries forwarded observations to Project OSCAR.
Solar cells were bought in batches of 10 or 20 from Radio Shack, and tested for efficiency by group members.
Once ready, OSCAR 10 was mounted aboard a private plane, and flown a couple of times to evaluate its performance and reliability.
Once it was found to be operative and reliable, the satellite was shipped to Kennedy Space Center, where it was mounted in the launch vehicle's third stageWhich one.
Es’hail 2 / QO-100 [4] Launched November 15, 2018.In geostationary orbit covering Brazil to Thailand.
Some satellites have a bulletin board for store-and-forward digital communications, or a digipeater for direct packet radio connections.
While the satellite is moving towards the ground station, the downlink frequency will appear to be higher than normal.
Many modern transceivers include a computer interface that allows for automatic doppler effect correction.
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 countries, in chronological order by date of launch, include: SuitSat, an obsolete Russian space suit with a transmitter aboard, was officially known as "AMSAT-OSCAR 54".
