Hi All Meridian 8 appeared to be launched (July 30, 2019) almost immediately after Meridian 3 stopped transmitting last summer. Here's a TASS report after the Meridian 8 launch saying all is good with the spacecraft. https://tass.com/science/1070982 This report doesn't seem to match months of radio observations and now a new Meridian-M is scheduled for launch this month. Meridian 8 entered Meridian 3's orbital plane and the orbit became synchronous in mid August. However, Meridian 8 didn't emit any signals on X-band or either of the UHF bands used by Meridian satellites. I lack C-band capability so don't know what is going on there. The rest of the constellation emits transponder and TT&C signals when the spacecraft is near apogee. The X-band tracking beacons can be seen here: https://twitter.com/coastal8049/status/1161140563611045889/photo/1 The image above was plotted last summer. I just revised the constellations status after noting a TASS report that the launch of Meridian-M is planned for this January. https://tass.com/defense/1104437 Here's a plot showing the X-band emissions from the tracking beacons for Meridian 2, 4, 6 and 7. No emissions are noted in the "Meridian 3 gap". Meridian 2's booster malfunctioned and placed it into a non-standard orbit. It has been in operation on X-band since I started monitoring there for at least 2 years, but it is not in a synchronous orbit and not part of the constellation. https://twitter.com/coastal8049/status/1214738381134938112 I find this unusual as from my understanding the new Meridian-M version of the satellite is simply a slightly improved variant of the Meridian satellite and four Meridian-M's were commissioned to replace aging Meridian spacecraft rather then develop new ones. So why would it have different operational behaviour then the rest of the constellation? That makes no sense as it implies that the ground segment would also need to change. I suspect the up coming launch may be a replacement for Meridian 8. If that is the case this new launch would occur into the Meridian 3's plane. The next oldest satellite in the constellation is Meridian 4 which as of today is operational. However, Russia did make a statement that it planned to launch two Meridian-M satellites in 2019, so maybe all is well with Meridian 8 because it's different and the new one is off to another plane...? https://tass.com/defense/1061195 We will not know what's going on until the NOTAM's come out for this launch. Has anyone ever bothered to look optically at the Meridian satellites? Regards, Scott Tilley Further reading on Meridian - http://www.russianspaceweb.com/meridian.html _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Tue Jan 07 2020 - 21:35:30 UTC
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