Space Station

Orbital Motion

I continued to experiment with my phone camera on November 28th as the International Space Station traveled through the constellations Draco and Ursa Minor in early evening. The Moon was quite bright that night, so my 10-second exposures at ISO 800 did not reveal a dark background sky. The bright streak in the center of the first picture below is the trail made by the Space Station during one 10-second exposure. You can also notice the dim trail of either an airplane or another satellite moving diagonally through the upper right of the picture.

Next is a 6-frame animation of the Space Station's motion covering approximately 2.25 minutes of elapsed time. Since the phone camera has a maximum exposure time of 10 seconds, there are missing gaps in the continuous Space Station path. I repeatedly pressed the shutter as fast as I could, but I included an automatic 2-second delay between pressing the shutter button and exposure initiation to let vibrations die down. Notice how the Space Station gradually fades away in the last frame. An unknown satellite or airplane streaks diagonally through the upper right.

The Space Station's altitude is approximately 260 miles, and it moves at roughly 17,130 mph! At this speed it can travel 1,000 miles in about 3.5 minutes!

My next attempt to capture the Space Station happened on December 15th. This evening the Moon was below the horizon, and the sky was dark when the Space Station passed nearly overhead. The next image shows 10 seconds worth of orbital motion as the station passed near the constellation Lacerta heading toward the Great Square of Pegasus. Cepheus, Cassiopeia, and Perseus are seen from left to right along the bottom of the picture. The Andromeda Galaxy is the tiny fuzzy smudge slightly to the right of center.

I misjudged the location of the Space Station's path as it passed near the zenith, so the previous picture shows the track off center. As the orbit continued I was able to get three consecutive images while the Space Station descended toward the southeast. The following 3-frame animation captures 40 seconds of motion and shows the path dropping through the constellations Pisces and Cetus toward the murky light polluted horizon.

I tried using the phone's video recording mode to capture continuous motion of the Space Station through the constellations. If the Space Station is bright enough, the phone camera detects it as a moving point of light, but the background stars do not show up during the short time exposures of each video frame. Thus, choppy animations like the two shown above are the best I can do with the phone to show orbital motion among the stars.