Today's Balloon CubeSat ULOG3 Launch from South India

 I came to know that a CubeSat ULOG3 was being launched on a helium balloon today morning. VU3KVB from Chennai was the amateur radio co-ordinator of the event and I was in touch him over phone from early morning. Though the launch was scheduled for 6 am, there was a delay of about one hour for the launch. After the launch VU3KVB informed me that he was able to hear the signals 5,9 on handheld radio with rubber duck antenna, even when the CubeSat was 30 km from his location. 


I was told that it had a 500 mW transmitter for sending SSTV images containing photographs taken by the CubeSat, overlaid with GPS data which would include longitude, latitude and speed of motion. Barometric data will also be provided by the barometric sensor. It had an 8000 mAH battery and was expected to reach an altitude of 32 km, being filled with about 800 gm helium. When the balloon bursts at high altitude, a parachute would be deployed and as per wind prediction, it would land somewhere in Dharmapuri district. Embedded GSM module will be enabled after 2 hours and would transmit data to the predesigned number till either its battery runs out or get switched off after retrieval.

I had informed other hams in the region over the morning Hambel Belgaum HF Net at 7 am and many were monitoring from various parts of South India. I too tried monitoring 435 MHz, the downlink frequency, with my Moxon Yagi pointed Eastward, for about 2 hours. According to an online line of sight prediction calculator, I thought the radio horizon from the CubeSat at 32 km altitude, will be around 737 km, while I was located about 275 km from there. Yet I could not capture any signals on the downlink frequency of 435 MHz. I am waiting for information from the team on how high the CubeSat had risen before the balloon ruptured. If it had not gone up as high as predicted, I had no chance of hearing the signals from 275 km distance! Couple of archived live streams during the launch are available on the Chennai Institute of Technology YouTube channel. I am glad to see that student teams in our region are also engaged in such technologically challenging activities!

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