Beacon Sequence and Format of BIRDS-2 CubeSats
All three CubeSats of BIRDS-2 project will be operating with same Uplink and Downlink frequency. Each CubeSat will transmit CW Morse coded beacon signal at 437.375 MHz. Telemetry and Mission Downlink will also be carried out using the same frequency but only upon successful Uplink Command. But since the CubeSats will be released at the same time from ISS, there is a possibilities that the beacon signals from three CubeSats will interfere with each other making it difficult to decode at ground. To avoid that, one of the measures adopted by the team is as described below.
The CubeSats will be released together, which means they will Turn ON almost at the same time. Once Turned ON, one of the first thing it does is to start transmission of beacon signal to indicate it is alive. But the CubeSats are programmed in such a way that each of them will wait for different amount of time before it starts the transmission of beacon signal. The first satellite coming out of the J-SSOD will be the first to start transmission of beacon and it will remain silent for long enough to let other two satellites finish their beacon transmission. The initial sequence is as illustrated in the picture below.
The initial beacon signal period is set as 115 sec (30 sec transmission and 85 sec silent time). This is a temporary solution for the initial operation phase.
The CW Beacon signal transmitted from the CubeSats has format as shown in the picture below, which also shows the definition of each hex digit of the house keeping data in the beacon signal.
The call sign and satellite ID of respective CubeSat will precede the housekeeping data.
BIRDS-2 CubeSat Name and Call Sign
The name of the three CubeSats of BIRDS-2 project and the call sign allocated to them as as follows:
|Country||Satellite ID||Satellite Name||Call Sign|
BIRDS-2 CubeSats in Space
Three 1U CubeSats developed by 11 students from Japan, Bhutan, Philippines and Malaysia at the Kyushu Institute of Technology (KyuTech) through BIRDS-2 project under the BIRDS program has been successfully launched on a SpaceX Falcon 9 along with resupply cargo to ISS (CRS-15) in a Dragon Capsule. The Dragon has been successfully captured and the CubeSats will now await release from ISS which is expected sometime in early August.
The CubeSats will operate in Amateur bands and the team would appreciate support from amateur community throughout the world to help us with initial acquisition of beacon signal. All three CubeSats will transmit Morse Coded CW beacon at 437.375 MHz.
More details related to satellite operation will be posted here. Stay tuned…