Sun Outage Period Oct 06

Zaphod

Interesting post by John Locker on Feedhunters group;

The cloud rolled in last night making it impossible to check out W3 visually
, however if the following is correct it looks like HB3 is also in trouble,

http://www.spacemart.com/reports/Eutelsat_Issues_Update_Hot_Bird_3_Satellite_Condition_999.html

For those who are not familiar with the Sun Outage period .......... which
is taking place over the next few days , basically
what is happening is the Sun is tracking directly behind the geo arc...which
means that through the day , each satellite in turn will suffer a potential
outage for anything up to ten minutes as it it swamped by solar radiation
causing the downlink to be degraded.

Conversely , through the night , the satllites will go into total shadow for
anything up to an hour.
This is a scary time for satellite operators as their birds need to rely on
back up battery power.

The control centres will be working overtime to keep their satellites
active.In some cases , transponders will be closed down in order to conserve
power.
Its a testing time .... lasting for a week , and its only just started.
The problems Eutelsat are having don't bode well for the next few
days......and it seems like HB3 may have suffered permanent damage.

If you want to see what the geosats look like out there in space , visit
http://www.satcom.freeserve.co.uk/geos.htm where you'll find some videos
and animations showing what happens to satellites as they go into shadow.

This is going to be an interesting period for feedhunters.....keep an eye
out for closed down transponders and indications of low power....and check
out the effects of solar outage yourself by tuning to the satellites at the
appropriate time.

Find out when a satellite will go into outage by visiting Jens excellent
site at :

http://www.satellite-calculations.com/

Just put in your location ( nearest city will do ) and select the
satellite(s) from the pick list...

for example at 1016 GMT today , the Astras at 19 east will suffer outage .
Chose a weak channel and watch for break-up ....even better , select one of
the analogue channels and watch the noise ( sparklies) increase as the power
drops.

All good fun....and serious business to the operators.

Feedhunting isnt just about finding new feeds...its about understanding the
physics and orbital mechanics behind the hobby.
This is where science becomes fun.....and you can see the results without
having to have any lab equipment.

watty

As ever Zaphod you post really interesting Articles.