Re: Mini OR: ISS

Those PortaBalls are complete freedom. Yes, the ideal tracker scope.
Joe Bob used one and it seems easy to setup, easy to use, nice height
and great views. Plus an ideal conversation starter.

Q: What the heck is THAT????
A: Well Sir, funny you should ask ...

And so on.

Rich Girard wrote:
> I hate to tell you all, you're using the wrong instrument for this, I have tracked the ISS 3 or 4 times easily with my 12.5" Portaball;-) It's easy because there the are no axis to follow, just push it where you want it to go!
>
> Rich g
>
> Sent from my iPhone
>
> On Aug 29, 2010, at 11:34 AM, Mark Johnston <mark@No-Spam> wrote:
>
>
>> As with many things practice helps. I have tracked airplanes for practice and there are enough of them about. With my big Dob I cannot allign any axis but one can try to think about what directions have to be adjusted as you push the dob and that helps lower the confusion of tracking by minimizing incorrect adjustment directions. I had good luck at the last GSSP with ISS tracking.
>>
>> A tricky part is the focus stage that wastes valuable on-target time with the complexity of focus. Also it is basically impossible to share the view for this sort of moving target. You have to know your scope and it's feel to track best. My dob is f/3.7 so I can remain at the eyepiece without a ladder (using a ladder to track is not very 'safe' or practical I should think).
>>
>> I liked David's thoughts on the zoom eyepiece. Acquire wide then zoom it down. I generally acquire wide by placing scope in front of the target by 1 second in a finder view and hope it crosses the view, then just stay wide with whatever eyepiece I selected (typically 120x) Wide view is better than no view.
>>
>> There was activity on software that could try to do this given ahead of time the path info (from heavens above). Here you acquire when it is farther away and track. I have a feeling only certain mounts would be qualified for this, mounts that can slew fast and interface with the computer in a way where the delta slew rate commands allow for broad enough offsets to slew the scope. Tricky but I do recall seeing this software (for what is is worth).
>>
>> Marko
>>
>> David Wright wrote:
>>
>>> If you align one of your mount's axis with the flight path coordinates,
>>> especially with an Alt/AZ mounting by pre-aligning the AZ and then using the
>>> Alt for the tracking if the flight path, I have found that very useful to
>>> track a fast moving object. 2nd if a 2nd person can keep centered the scope
>>> on the ISS through the finder, then you have a much better shot at getting a
>>> high powered view of it. Third if you own a zoom eyepiece this can help you
>>> get your high power view once you're on it.
>>>
>>> -----Original Message-----
>>> From: tac-bounces@No-Spam [mailto:tac-bounces@No-Spam] On Behalf
>>> Of Rob Jaworski
>>> Sent: Sunday, August 29, 2010 9:56 AM
>>> To: TAC mailing list
>>> Subject: Re: [TAC] Mini OR: ISS
>>>
>>> I was going to suggest, practicing on airplanes first. But yeah, trying to
>>> track by hand isn't really that good of an option.
>>>
>>> What about the idea of taking a mental picture? Get ahead of the fast
>>> moving
>>> object and let it come nicely in the center of your FOV, then when it's
>>> centered, quickly close your eyes and concentrate on that image that's
>>> temporarily burned into your short term optical memory. I've tried this
>>> with,
>>> say, license plates, and am able to read them back from that mental image a
>>> whole lot easier than trying to memorize it quickly.
>>>
>>>
>>>
>>>> I haven't heard of heaves-above. What are they heaving?
>>>>
>>>>
>>> Maybe I was thinking that's how the HEAVE the station up into orbit, give it
>>> a
>>> big push? :-)
>>>
>>> This site is good too:
>>> http://www.heavens-above.com/
>>>
>>> BTW, folks, *excellent* talk last night at Houge, as expected. Dr Seth
>>> Shostak
>>> is one lively speaker, quick on his verbal toes, a lot of fun.
>>>
>>> -Rob
>>>
>>>
>>>
>>> ----- Original Message ----
>>> From: Bill Maney <bill.maney@No-Spam>
>>> To: TAC mailing list <tac@No-Spam>
>>> Sent: Fri, August 27, 2010 2:20:05 PM
>>> Subject: Re: [TAC] Mini OR: ISS
>>>
>>> Rob,
>>> Despite my wide field, I'd say it takes less than 2 seconds to cross the
>>> field at the zenith. I did a mixture. Sometimes I'd set my finder
>>> crosshairs well ahead of the trajectory and then watch through the
>>> scope. And other times, once I had it, I just tracked along looking
>>> only through the eyepiece. This seems to work better for me, even
>>> though the scope is not as stable, I think because I have time to parse
>>> what I see. I had a nice stretch of 10 seconds or something before I
>>> hit the zenith stop where it was centered and clear. It helps that it
>>> was going through the zenith so it was almost all alt and not much az.
>>> A little nudge now and then was the worst way because the scope settling
>>> time is around 1 sec. Maybe a bigger nudge in the right direction would
>>> work better, but the direction is always slowly changing and I missed it
>>> when I tried this. For my son and my neighbor, I could look through the
>>> finder and track while they looked through the eyepiece. Probably the
>>> best way of all.
>>> I practiced on planes before the event. They go over my house to SFO so
>>> at first, on the horizon they are easy to track and then get faster and
>>> faster (angularly speaking). Good fun.
>>> For the 9:30 event, I wished I'd had a moon filter. It's too bright.
>>> For the 8:30 pass, it seemed ok since the sky wasn't so dark.
>>> I haven't heard of heaves-above. What are they heaving? :)
>>> Bill
>>>
>>> Rob Jaworski wrote:
>>>
>>>
>>>> I went to heaves-above last night and found that the ISS had just passed
>>>>
>>>>
>>> nearly
>>>
>>>
>>>> overhead a few minutes before. And it was estimated to be a -3.5 mag.
>>>>
>>>>
>>> Darn!
>>>
>>>
>>>> Glad you were able to see it, Bill. I'm curious. You did have a nice
>>>>
>>>>
>>> wide
>>>
>>>
>>>> FOV,
>>>>
>>>> but did you track it by hand, giving the scope a little nudge every now
>>>>
>>>>
>>> and
>>>
>>>
>>>> again?
>>>>
>>>> -Rob
>>>>
>>>>
>>>>
>>>> ----- Original Message ----
>>>> From: Bill Maney <bill.maney@No-Spam>
>>>> To: TAC mailing list <tac@No-Spam>
>>>> Sent: Fri, August 27, 2010 11:29:37 AM
>>>> Subject: [TAC] Mini OR: ISS
>>>>
>>>> My 9 year old son and I saw the ISS with my 12.5" dob, f/5, 35mm 72deg
>>>> eyepiece from the Redwood City area last night (thurs) at around 8:30.
>>>> It was a perfect path straight overhead. We could easily see the solar
>>>> panels on either side of a small blob, even when it went overhead.
>>>> I had also looked the previous night (wed) at 9:30 but I think the
>>>> orientation was different. I saw something out to the side, smaller
>>>> than I expected, but as it moved across the sky the perspective changed
>>>> and it looked like a blob as it disappeared. This pass was to the
>>>> west of me. An attempt to see it at around 8:05 was unsuccessful, so I
>>>> was redeemed last night.
>>>>
>>>> It seemed odd to me that last night the panels were apparently facing
>>>> down toward the earth instead of west toward the sun. I guess an hour
>>>> after sunset, there's already some angle. It also seemed odd that I
>>>> could see more on an earlier pass, but maybe that makes sense too. I
>>>> guess if you want to see the panels wider, look when the path is east of
>>>> you, later in the evening. Or catch it against the disk of the sun!
>>>> There's another pass tonight at 8:26, but it's a bit too low (24 deg
>>>> max). Should be better farther north though.
>>>> Bill
>>>>
>>>>
>>>>
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>
>

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