Cassiopeia Observatory

International Space Station (ISS) Imaged!

Posted: 29 August 2012

After more cloudy nights, the monsoon pattern took a break on Tuesday, 28 August 2012. The observatory was opened at 1834 MST, 97°F. First object was the moon, still in a tree, at 1841 MST. I then updated the International Space Station TLE using the AutoStar for this night's excellent pass. At 1849 MST, I began preparing to image the International Space Station using the 8" LX200-ACF and D7000 DSLR. Mounted the camera at prime focus using the star diagonal. Focused on the moon, locked the telescope focus, and tweaked the finderscope alignment. I did a test HD video recording of the moon using the same exposure settings I would use for the ISS: 1/2000sec, ISO 2000. This is a frame from that video:

By 1911 MST, 10 minutes before the pass was to begin, all was in readiness. The bright sky about 30 minutes after sunset and some trees at the AOS point would make acquiring the station difficult. Two minutes before the pass was to begin I accidently hit a button on the handcontroller and cancelled the pass tracking! Egads! I quickly reselected the ISS and the telescope went through its pre-pass movements. Fortunately, it completed that just as the pass began. Whew. I had some initial difficulty in locating the ISS but once I did and got it centered in the finderscope, tracking was initially good. Tracking did go bonkers as the station neared the meridian, high in the northern sky, but once I reacquired the ISS in the finderscope east of the meridian, tracked was good again. The HD video recording was 5 minutes, 30 seconds, at 1/2000sec, ISO 2000. This is one frame in the recording from near the middle of the pass to show the scale of the ISS vs the moon (seen above):

This next image is an animated GIF made with 11 cropped images from the video showing the changing perspective of the ISS as it moved along in its orbit:

After the ISS pass was over, I removed the camera from the telescope and did some brief lunar observing at 77X, 206X, and 364X. Seeing was not good, but there were still some nice views along the terminator. I then tried to locate the precise location of the Apollo 11 landing site using Pete Lawrence's How to Locate Tranquility Base on the Moon. Unfortunately, the poor seeing combined with the high sun angle made it impossible to see the final two pointing craters. I will try again when the moon's phase is better for locating Tranquility Base.

As I was closing up for the night, I took this photograph of the moon, full-frame, f/8, 1/320sec, ISO 100, 300mm, to show the scale of the moon vs the size of the moon and ISS as seen in the full-frame images at the beginning of this report:

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