Amateur Radio Missions

MRZN transmits a telemetry beacon in standard AX.25 UI frames on 435.500 MHz (requested frequency, subject to IARU coordination), using 2GFSK at 9600 baud. The beacon carries the satellite's status data: battery voltage and current, solar panel current, temperatures, operating mode, uptime, reset counter and attitude control status. The frame format and a decoder are published on this site and in the open repository, so that stations around the world can receive and decode MRZN and share their observations. Reports from radio amateurs directly help the team assess the satellite's health. The source field of every frame carries the satellite's callsign, so the beacon also identifies the station.

MRZN transmits a CW beacon with its callsign and short messages that change during the mission, such as greetings, event keywords and anniversary messages. Anyone can copy CW by ear with a simple receiver or a low-cost SDR, with no special software. That makes this mission accessible to newly licensed radio amateurs, school clubs and shortwave listeners. Anyone who copies the beacon can submit a reception report on this site with the date, time, location, copied text and their callsign. The team checks each report against the satellite's transmission log and confirms valid receptions. This service is used to organize on-air activities: “copy the keyword” events, listening sessions at schools and contests in which participants decode the current message.

MRZN transmits the mission's QSL card as an SSDV (Slow-Scan Digital Video) image. SSDV splits the image into small packets that are decoded independently: the image is completed over one or more passes, and several stations can pool their packets to complete it together. The team publishes open-source software to demodulate and decode the SSDV packets, along with instructions for uploading received packets to a shared image server. Stations that receive the image submit a reception report on this site. For each validated reception, the team emails the high-resolution QSL card.

MRZN demonstrates store-and-forward amateur radio communication (PACSAT-style). A remote ground station, operated by the team's licensed radio amateurs, records local weather variables (temperature, humidity, pressure, rainfall and wind) and uploads them to the satellite during a pass. MRZN stores the data on board and later transmits it openly, so that any station within the footprint can receive it. The data packets use a published, unencrypted format with an integrity check (CRC). The team publishes open-source software to decode them, and all received data is also published on this site. The mission shows how a small amateur radio satellite can relay data from isolated sites without terrestrial communications infrastructure, a capability useful for emergency communications preparedness in Central America.

MRZN carries a small camera that takes photographs of Earth, mainly of Honduras and Central America. The control station commands each photograph. The satellite points the camera toward Earth with its magnetic actuators, takes the photograph and stores it on board, keeping radio silence while it does so. During a later scheduled pass over the coordinated area, MRZN transmits the image unencrypted, so that any amateur radio station within the footprint can receive it. Each image is a compressed JPEG file of about 70 kB. It is sent in small, independent packets with an integrity check, in a published format. The image repeats during the pass, and a station can complete it over several passes. The team provides open-source software to decode the images and publishes each received image on this site, crediting the stations that received it. This is an educational imaging experiment. It shows students and radio amateurs how a small satellite captures, stores and transmits images. The images are not used for any commercial or governmental remote-sensing purpose.