Astra 2E: General Discussion (Post-Testing)

[Huevos]

Sometimes the tracking calculation is based on projected movement over the last week not actual movement,
I would not be surprised to see Astra 2E at approx 36 east (moving 0.80° W/day) by next Wednesday.

WG has been monitoring the position optically. No sign of movement so far.

 

[william-1]

WG has been monitoring the position optically. No sign of movement so far.

Thanks for the info no surprises in store then,

This must be the most monitored satellite since Astra 1D.

 

[M60]

Thanks for the info no surprises in store then,

This must be the most monitored satellite since Astra 1D.

It certainly features high up on n2yo's most tracked list.

 

[Pride Of Cucamonga]

North of the footprint its the same story. Going up in the moment, gradually since may and now quite steep since october. In the moment it seems to level out.

I think it might have something to do with climatic conditions. If there is cloud cover - quite high - or a proper haze it seems to work better than in bright sunshine - and no, its not the lnb wandering.

I doubt it's the weather as, like i say i'm getting a stronger signal in torrential rain now than i would in torrential rain 3 months ago. I wonder if it's to do with the tilt of the earth?

 

[woborny]

Here is a copy and paste from a german forum, via another forum, via another forum...made up, real, translation issue, one part of SES not knowing what the other is doing and replying differently?

Dear Sir, Madam,
Thank you for contacting SES and for your enquiry.
the astra 2e will be start operation mid december
Kind regards,
The SES Team
Danke für die Info. Dann müsste er sich ja demnächst auf den Weg nach 28,2° machen. Ob die vor Weihnachten noch umstellen wollen?

 

[cazhh]

I doubt it's the weather as, like i say i'm getting a stronger signal in torrential rain now than i would in torrential rain 3 months ago. I wonder if it's to do with the tilt of the earth?

I've thought for a long time that the forces originated by the sun are one of the major factors which makes the satellite move.

A few weeks ago i've found this treasurechest: http://microsat.sm.bmstu.ru/e-library/Algorithms/algorithms.htm
In there especially this PDF:
http://microsat.sm.bmstu.ru/e-library/Algorithms/CommonDesign/Chapter2SatelliteDynamics.pdf
which describes very well how it's working.

I cite:

The torque resulting from solar pressure is the major long-term disturbance torque
for geosynchronous spacecraft.
...
For momentum bias and three axis stabilized spacecraft the major
portion of the solar pressure torque is usually due to the solar panels that track the sun.
Usually the solar panels only have a single gimbal, which is about the 3-axis or pitch
axis. Thus, they are always within 23 degrees of the Sun and the loss of power from not
pointing directly at the sun is offset by not having the added complexity and weight of a
double gimbal system to directly track the Sun.
...
Note that the pitch torque is periodic, hence its effect over one orbit is zero. However, the
roll and yaw torques have secular components which mean that over one orbit there will
be a net change in the spacecraft angular momentum.

You can bet that the angle between the satellite and the sun plays an important role here.

Unfortunately, there are some issues. The change of SNR over time as i have posted it earlier is neither symmetrical, nor steady. Ie the SNR was already pretty bad beginning of march, while it started to improve again beginning of september.
Also, if you look at the picture there have been quite a few "jumps". The most prominent one starting on the 23rd of Oct. I fail to see how this could be explained only by the changed angle between the sun and the satellite.

Another interesting effect is that there is a summer and a winter curve.

Summer:



Winter:



The interesting part is the time between summer and winter "modes". There was no switch or slow transformation, it sometimes morphed back and forth again. That process took weeks.



My guess is that the attitude control computer somehow seems to want to stick to "last weeks" mode. Speculation.

The next spring will tell us more.

 

[mickwig]

Is it not also possible, that the conditions in the center of the footprint are diffrent in summer or respectivly winter. So maybe the operater has monitoring stations in the center of the footprint and the changes the overal output of the transponders according to the reception conditions there, a bit like a gate in music where you would let one signal control the volume of another signal?

 

[M60]

Here is a copy and paste from a german forum, via another forum, via another forum...made up, real, translation issue, one part of SES not knowing what the other is doing and replying differently?

Dear Sir, Madam,
Thank you for contacting SES and for your enquiry.
the astra 2e will be start operation mid december
Kind regards,
The SES Team
Danke für die Info. Dann müsste er sich ja demnächst auf den Weg nach 28,2° machen. Ob die vor Weihnachten noch umstellen wollen?

Different responses to people's emails by SES's PR team all seem to arrive at this same date, problem is we know in the past they aren't exactly spot on with their info.

I'll try emailing them myself but suspect I'll get the same response.

 

[cazhh]

Is it not also possible, that the conditions in the center of the footprint are diffrent in summer or respectivly winter. So maybe the operater has monitoring stations in the center of the footprint and the changes the overal output of the transponders according to the reception conditions there, a bit like a gate in music where you would let one signal control the volume of another signal?

You can deduce from the reports by the people in the sidelobes that it is (mainly) a beam movement. When my SNR gets better, people on the other side of the NULL report a worse one. Of course we have to few people really measuring, so we'd need more data, but the overall tendency seems to be there.

 

[bema]

http://www.eta.chalmers.se/~muy/weather/wx/grafer_astra.php

October (and partly November) was the worst month here for 2F reception. Bad weather and most of all low signal...

 

[Schroeder]

TLE

Different responses to people's emails by SES's PR team all seem to arrive at this same date, problem is we know in the past they aren't exactly spot on with their info.

I'll try emailing them myself but suspect I'll get the same response.

well for 2E to be operational by mid December it needs to start moving in the next few days, no apparent sign of it moving so far although if I remember correctly from 2F was a day or so before the TLE caught up with the movement, similarly at the end of the movement ws a day or two before the TLE placed it at 28.2E.

 

[solly]

tle will be update Monday set see astra 1h 41.20 east for now

 

[M60]

TLE


well for 2E to be operational by mid December it needs to start moving in the next few days, no apparent sign of it moving so far although if I remember correctly from 2F was a day or so before the TLE caught up with the movement, similarly at the end of the movement ws a day or two before the TLE placed it at 28.2E.

Yep, agree. If they want it there by mid December then we're looking at 10 days (assuming it's raised to the same height as 2F) so will have to begin moving by Monday to get there for the 12th. I suppose though, considering we are all pretty much in agreement nothing will migrate from 1N this side of Christmas/New Year now, any platform lockdowns over the holiday period won't stop SES moving and testing 2E at 28.2E as it's not service affecting to any other satellites or broadcasters at that position.

Saying that, I'd guess even Bedsdorf HQ winds down somewhat over the holiday period (non Operationally) which to most will begin around the 20th. They may raise it's orbit lower, as per 1H, which to my calculations would then take 25 days at 0.59W/day and be ready then for early January - irrespective of what SES's PR tell us! We'll find out in due course!

 

[solly]

astra 1h next 7 days will be 37.5 east
on 7 December

 

[ettore88]

Hi to all!!!I ask you one bit of information in regard to the movement of the Bbc tv channels on 2E...When will be moving these channels?In december?Thanks in advance!!!

 

[AHMET_YILDIRIM]

I think it is started to move

http://www.n2yo.com/?s=39285

 

[Analoguesat]

Hi to all!!!I ask you one bit of information in regard to the movement of the Bbc tv channels on 2E...When will be moving these channels?In december?Thanks in advance!!!

We dont have any definite info yet. Its looking unlikely they will move before Christmas now though.

 

[Lazarus]

Hi to all!!!I ask you one bit of information in regard to the movement of the Bbc tv channels on 2E...When will be moving these channels?In december?Thanks in advance!!!

Some info from SES suggests 15 Dec (Which I received indirectly and privately, so is a. Unattributable and b. Not necessarily reliable - if at all!), but there have been delays already and also SES PR is next to useless.

In order for that to happen, the Bird needs to start its transit from 43.5E tomorrow at the latest.

If not 15 Dec, then not until January.

 

[M60]

I think it is started to move

http://www.n2yo.com/?s=39285

You got me excited for a minute just then!! TLE's aren't updated over the weekend so I don't suppose we'll know until early next week.

 

[ettore88]

Thanks guys!