To celebrate the 50th anniversary of the first human spaceflight by cosmonaut Yuri Gagarin, the ARISSat-1 satellite aboard the International Space Station will be on the air using the station’s external antenna. Transmissions will begin on Monday, April 11, at 14:30 UTC and continue until 10:30 UTC on April 13.

To preserve the satellite’s battery, transmissions will cycle on and off. ARISSat-1 will transmit for 40 to 60 seconds, and then remain silent for 2 minutes.

The FM transmissions on 145.950 MHz will alternate between a voice ID, telemetry values, SSTV images and audio greetings in 15 different languages. One of the transmissions will contain audio of a conversation between Gagarin and ground controllers that was recorded during the historic flight. Specific only to this event, planning is currently underway to provide an additional FM broadcast downlink at 437.550 MHz.

A CW beacon will be heard on 145.919 MHz cycling between the ARISSat-1 call sign, telemetry and call signs of individuals involved in the ARISS program.

BPSK-1000 telemetry transmissions will also take place on 145.920 MHz SSB using the new 1kBPSK protocol developed by Phil Karn, KA9Q. Software for demodulating the BPSK-1000 telemetry is available here.

AMSAT will issue commemorative certificates to listeners who receive the ARISSat-1 transmissions. Reports can be e-mailed to Gagarin@arissat1.org. Include your name, call sign, a description of what you heard and the UTC time you heard it. Recording the battery voltage telemetry values and the UTC time you received them will be especially helpful.

You can determine when the International Space Station will be passing overhead by using the AMSAT-NA online pass prediction tool.

--Information for this story provided by AMSAT-NA