Discover and read the best of Twitter Threads about #meridian
Most recents (4)
It turns out that #Meridian 9's apparently odd Argument of Perigee appears to be expected. While traditional thinking about the molniya orbit expects an AoP ~270 it turns out Meridian uses starting values of AoP of ~270 and ~295 degrees. MORE 
There are four active satellites in the constellation. Two pairs are always at opposite apogee from each other and these pairs have AoP of 270 and 295. Presently M4(270)-M6(295) and M8(295)-M7(270). I've indicated the AoP for each s/c in the pair. MORE
Now if you examine the constellation history a pattern emerges. Meridian 8 shares the same initial AoP as Meridian 3, the s/c it replaced... MORE
#Meridian 9 Launched less than 24 hours ago is active high over Siberia on what I believe is the constellation TT&C frequency 3408MHz. This is the sound of a baby Meridian! 25dB SNR even through thick trees so its loud!
The next few weeks will be really educational about the operational characteristics of the Russian Meridian system. Usually new satellites exercise a range of their characteristics before they settle into routine behaviour.
Further we will hopefully get some sort of resolution to the mystery of Meridian 8
Here's a summary of why I'm watching the #Meridian-M launch with interest.
Before the launch of Meridian 8, Meridian 3 stopped communication transponder activity and created a 'gap'. I called this the Meridian 3 gap. MORE...
Before the launch of Meridian 8, Meridian 3 stopped communication transponder activity and created a 'gap'. I called this the Meridian 3 gap. MORE...
Normally the Meridian constellation has 4 operational satellites and as you can see from the Doppler plot in this attached tweet from last year they are spaced so that there is always an active satellite over North American or and Russian apogees.
Meridian satellites launch into a Molniya orbit and then drift for about 10-14 days. The older satellites seemed to do this for less time and the new Meridian-M a little more. Once in the plane they desire they sync the orbit to 2 revs every sidereal day.
#MERIDIAN 6 on X-band. Meridian 8 is rising to apogee now so lets see if it is active on X-band... If you recall, Meridian 8 replaced meridian 3 last summer but I never heard emissions from M8... Wonder if this is why there's a new launch scheduled for January?
For those wondering what I'm going on about... The #Meridian constellation is a Russian military communications system in high Earth orbit serving the high latitudes of Russia. russianspaceweb.com/meridian.html
Last summer Meridian3 stopped transmitting and Meridian8 was launched in same plane. After a few months of monitoring Meridian8 I didn't see emissions until other priorities here caused me to stop listening. Then TASS just announced another #Meridian-M launch for this January...
