[amsat-bb] Long shot: August eclipse intersecting any Oscars?

[Graham Shirville]

Hi All,

To follow on from David's email,  I can confirm that EO73 has already 
experienced an eclipse - this was back in March 2015. The solar panel WOD 
results are detailed here 
https://funcube.org.uk/2015/03/20/solar-eclipse-update/ and we have the 
records for all the available telemetry stored in the Warehouse if anyone 
would like more detail of what happened.

We are fortunate to have Whole Orbit Data available in addition to the Real 
Time channels so it should be possible to gather lots of information next 
month. Of course the EO-88 and UKube-1 CubeSats also carry similar FUNcube 
payloads so these spacecraft could also be checked to see if their orbits 
will "see" the eclipse.

73

Graham
G3VZV

-----Original Message----- 
From: David G0MRF via AMSAT-BB
Sent: Friday, July 14, 2017 8:18 PM
To: amsat-bb at amsat.org
Subject: [amsat-bb] Long shot: August eclipse intersecting any Oscars?

Hi Greg

Sorry, only just seen your post.

I believe the answer is yes.  I'll have a look at the exact pass times over 
the weekend.

AO-73 will fly through the path of the eclipse on the 21st August and the 
effects should be seen on its real time telemetry.

AO-73 has temperature and light sensors on its solar panels and this data is 
collected and sent every 5 seconds.
You should easily see the change in light levels and perhaps, a change in 
external temperature as heat energy is lost as IR radiation. - Although this 
will depend on the degree of coverage of the sun during the satellite pass.

You may also see the total panel current ( The sum of the current supplied 
by the solar panels) drop dramatically.
Fortunately most LEO sats are designed to handle 'eclipses' of 35 minutes, 
so this minor glitch in power collect should not adversly affect operation.

All of these will be displayed as graphs if you are collecting data on the 
Funcube dashboard. - Free windows download.

In the case of AO-73, it usually switches to transponder mode in eclipse. 
Will it do that on the 21st ??

Good luck. If you give it a try, let us know how you get on.

David


Hi folks,

I was asked this on our club's weekly net last week.  I expect the
answer is no, but thought I should check...

Will any of the ham satellites be affected by next month's solar eclipse
across the USA?  To be affected, the satellite's track (at some 18,000
mph) would need to intersect some portion of the eclipse (not
necessarily the path of totality), which I understand is moving at some
1,500 mph.  Given the speeds involved, that's unlikely.  But we've got a
number of satellites in sun synchronous orbits, so it's not impossible.

Any way to predict this?

If there are any, the telemetry from the event would be an awesome bit
of data for students' analysis.

Greg  KO6TH

p.s.  I remember being at work (I think in the 1990's) during an
eclipse.  As I recall, the spot of totality was out in the Pacific
Ocean, off the coast of Mexico.  The real-time satellite weather
background on my Unix workstation looked like someone had burned a hole
in it with a cigarette.

_______________________________________________
Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions 
expressed
are solely those of the author, and do not reflect the official views of 
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb