Following the currently high solar activity now also the most recent 1U BEESAT satellite, BEESAT-9 (project website, NORAD ID 44412, information for radio amateurs), is re-entrering Earth’s atmosphere. The latest prediction by the German Space Situational Awareness Centre (GSSAC) is 2024-06-04 06:35:45 (UTC) (prediction from 2024-06-01 13:04:55 (UTC)). With each of the predictions the re-entry time shifted a little bit backwards but also the possible interval is decreasing. We therefore expect the satellite to re-enter on Tuesday morning to midday.
Similar to previous re-entries (BEESAT-4, BEESAT-3, and BEESAT-2) we would love to cooperate with radio amateurs. At the moment we are using ground stations in Berlin, Germany, and Svalbard, Norway for the communication. But it is planned to transmit telemetry again over SatNOGS ground station all over the world. As BEESAT-9 has a functional GNSS receiver we will try to include this telemetry also in the transmissions. A decoding of the telemetry and a rapid provision of them but be very beneficial to use the GNSS to correct the TLEs. But we also know that our support of that had been lacking (still only GNUradio 3.8) and implementing it with gr-satellites is not trivial, still it would be very much appreciated. Alternatively recording IQ data besides the normal wav files can help us to decode more data in the proceedings of the re-entry.
Besides GNSS we will also perform STRF recordings as a backup. When we will created new TLEs from either method we will publish them here and into a git repo (which I will share then). Recordings/TLEs by others (435.95 MHz) would also highly appreciated.
Newest prediction of GSSAC with epoch of 2024-06-02 02:27:06 (UTC) is 2024-06-04 06:45:50 (UTC). This would be quite cool because it would be right after our Berlin passes giving us the chance to download telemetry at a very low altitude.
In my previous post I accidentally posted the non-propagated TLE set, while it is good approximation the propagated below based on the same data is more accurate:
Thank you @fredy for the TLE updates. They really helped us during our last Berlin pass of the day. Unfortunately we had a satellite reset at around 14:31:10 UTC. As we did not received any decodable telemetry during the following low Svalbard passes and one Berlin pass we did not know that until 17:05:56 UTC. We then were able to upload the auto transmissions again for the following times:
Latest prediction for re-entry is 2024-06-04 08:14:04 (UTC) (made by GSSAC at 2024-06-03 22:56:48 (UTC) based on TLE epoch 2024-06-03 03:38:04 (UTC)). If we have sufficient TLEs we hope to conduct the two passes over our Svalbard and Berlin ground stations currently predicted at 05:03-05:16 UTC and 06:31-06:43 UTC. In case of another reset auto transmissions will be scheduled for the following orbits (05:53-06:02, 06:27-07:02, 07:50-08:25).
Would there be interest in live streaming those last passes from our mission control center? We are not sure if we will have the time for managing that, but if so I would post a link here or in satnogs matrix chat.
It took us a while but here are some more insights from the BEESAT-9 re-entry campaign. We were also able to decode multiple frames from the EIRSAT ground station observation that @fredy shared.
The re-entry occurred on 04th June 2024 at around 08:28 UTC. As this was our fourth CubeSat re-entry within a year we were able to apply many lessons learned, which were also discussed in our recent paper. Some key highlights from this re-entry:
Last telemetry decoded at 08:04:55 UTC at an altitude of only about 102 km within 30 minutes before burning up.
Drastically increased temperature values between 89 °C and 187 °C from all 24 thermal sensors in the last frame (see image below), with values during nominal operations only between -5 °C and 35 °C.
Several valid GNSS frames during the last 3 orbits with an altitude between 169 km and 102 km.
Angular rates exceeding 50 °/s.
Last transmissions seen on 5 Irish SatNOGS ground stations (latest for each observation between 08:04:42 and 08:05:05 UTC, see @fredy post above).
These data receptions very late into BEESAT-9’s decay were only possible through constantly new generated TLEs by @fredy, many thanks for that! Additionally, a cooperation with the German Space Situational Awareness Centre (GSSAC), provided precise re-entry predictions and thereby allowed us to accurately plan the end-of-life operations. An in-depth analysis of the BEESAT-9 re-entry will be presented at IAC 2024 in October.
Images:
Last image from BEESAT-9 showing the Moon above the Earth’s horizon, date and time: 22nd of May 2024 at 16:27:32 UTC.
Student satellite operators Julian Harbeck, Oisín Smith, Anton Große Siestrup and Victoria Koßack with the Engineering and Qualification Model and the Development Model of BEESAT-9 in the Mission Control Centre after conducting the final BEESAT-9 passes.
