Re: Meridian 8: failed or just different?

From: Alain Figer via Seesat-l <>
Date: Wed, 8 Jan 2020 08:11:13 +0100
H Scott,

>  Has anyone ever bothered to look optically at the Meridian satellites?

My photographic observations at the Meridian constellation are summarized
in my blog here :

"Les satellites russes MERIDIAN"


Alain Figer
48°67 N ; 2°13' E ; 170m a.s.l.

Le mer. 8 janv. 2020 à 04:34, Scott Tilley via Seesat-l <>
a écrit :

> 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.
> 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:
> 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.
> 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.
> 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...?
> 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 -
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Received on Wed Jan 08 2020 - 01:12:00 UTC

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