Observing the ISS

[sheeny (Al)]

So with a shuttle up and docked on the ISS is anyone planning to try to view it or image it?

Clouds seem to be parting here today, so I'll do a run through Satscape and Heavens-Above this arvo when I get home from work to see if I'll get any favourable passes.

For anyone else that's interested I've been filling in some of my cloud-bound days/nights doing some calculations:

The ISS orbits between 320 and 410km above the earth.
Most of the modules of the ISS are 4 to 5 metres in diameter.
When crossing the horizon, the ISS is about 2116 kms away.
Based on Dawes Limit the minimum apertures to resolve the 4m diameter modules of the ISS are:
50mm for altitudes of 75 degrees or higher;
70mm for altitudes of 45 degrees or higher;
80mm for altitudes of 35 degrees or higher;
90mm for altitudes of 30 degrees or higher;
180mm for 10 degrees or higher.

I have read that at 50x magnification there is plenty of detail to see on the ISS, but I haven't achieved that yet. At 20x I can say there's no detail at about 60 degrees altitude (20x80 Binoculars).

Because the ISS moves so fast across the sky, tracking is always going to be the challenge especially at high magnifications.

Feel like a challenge?

Al.

[meade expert]

onto it...!!

[tornado33]

its due over Newcastle tonight at 19:09:25 , it will be 37 deg high to the North.
Im especially keen to see it as it wil be brighter with the new huge solar array extended
Scott

[Gargoyle_Steve (Steve)]

I wanted to have a go here (north of Brisbane) but it was clouded over again, as it has been so much of late. Would have been 44 degree elevation here from memory. Oh well!

[sheeny (Al)]

Still hoping for fine weather here.

Tonight I get a pass at 45 degs alt. before it disappears into the shadow.

Tomorrow night I get 2 visible passes at 18:17 and 19:53 but both are pretty low: 35 and 16 degs.

Monday night's a 49 deg alt pass for me.

All I need is clear sky...

Al.

[tornado33]

I saw it come over, it went red and dissapeared as it went into "sunset" as it passed due north. It wasnt a good appearance, low in the sky but still quite bright, the new solar panels im thinking.
Scott

[sheeny (Al)]

I got home late this arvo, but thought I'll have a go. While the roast was cooking I set the scope up in the driveway, drift aligned (I jagged it actually! ), shut down and did a full auto align to get it as accuarate as possible. Downloaded the an accurate chart from Heavens-Above (attached) and let the scope cool over dinner with the 32mm EP in it (63.5x). This is about the widest FOV I can get without the F6.3 reducer, and the magnification should be OK.

Dinner was ready just after 7. Finished that and outside to see what I could do. With more time I would've set up the TouCam for a wide field shot and the 20 x 80s as well, but time was running short now... Punched beta Lupus into the goto... oops... wrong end of Lupus but never mind... star hop up to HIP 75501 (arrowed).

With a bit of luck the ISS should go through the FOV...

All set with not much time to spare... ISS is approaching. I watched it till it was about halfway between Jupiter and where I had the scope set then glued my eye to the EP... nothing. Oh well... you get that!

I'm not sure if it faded before reaching my FOV or not, but it did look by eye to be a little lower in the sky than the indicated path in the chart, so perhaps it passed just outside my FOV.

It would be nice to have a bit more time to plan and setup, to have 2 or three stars on the path identified, so if it goes past one I could get the scope to jump to the next. Viewing the ISS always clashes with dinner! I don't if it would be quick enough or not, but there's one way to be sure.

I'll definitely have another go at setting up on a fixed point on the path again, but I might include my f6.3 Focal reducer next time to increase my FOV...

Tomorrow night might be a bino's job if it's clear, to see if I can pick both fly bys.

Al.