If you’d like to watch the International Space Station fly over your back yard this week you’ll want to be outside before dawn. ISS visible passes go through cycles due to Earth’s rotation below the station’s orbit. This week the visible passes are in the morning for North America. Remember we’re able to see ISS reflecting sunlight when it passes over our location just prior to sunrise or following sunset.
This week we have an even more intriguing chance to watch ISS followed by a Russian Soyuz spacecraft on Thursday and Friday mornings 16 and 17 December. The ISS Expedition 26/27 Crew will be launched to ISS aboard Soyuz 25 on Wednesday, 15 December at 19:09 UT (2:09 pm EST). The Soyuz will dock with ISS Friday afternoon. It takes about 46 hours from launch to docking for Space Shuttles, Soyuz, Progress and other spacecraft. By now I hope you have figured out where I’m going with this.
If there is a visible ISS pass at your location on Thursday or early Friday I suggest you watch for the Soyuz following ISS. I expect Soyuz 25 will be trailing ISS by at least 20 minutes on Thursday morning. On Friday it should be following ISS by a minute or two, since it will be about 7 hours from rendezvous and docking for observers in the Americas. Click the Heavens-Above link on the right side of the page to check pass times for ISS and dozens of other spacecraft for any location in the world. I have had the good fortune of seeing ISS flying in “formation” with Space Shuttles and a Russian Progress cargo spacecraft. Progress and Soyuz are very similar in size. Once Soyuz TMA 20 has launched I expect orbital tracking data will be available on the websites linked below.
Image above: The Soyuz TMA-20 spacecraft is rolled out by train on its way to the launch pad at the Baikonur Cosmodrome, Monday, Dec. 13, 2010, in Kazakhstan. The launch of the Soyuz spacecraft with Expedition 26 Soyuz Commander Dmitry Kondratyev, NASA Flight Engineer Catherine Coleman and Italian astronaut Paolo Nespoli is scheduled for Wednesday, Dec. 16. Image Credit: NASA/Carla Cioffi
For observers in Kentucky and Southern Indiana visible ISS passes will occur as follows:
Tuesday 6:50-6:54am WSW>SE peaking 45 degrees;
Wednesday 5:43-5:44am E>SE peaking 25 degrees;
Thursday 6:08-6:10am S>SSE peaking 30 degrees
You can also “observe” Soyuz/ISS passes via radio. During orbital operations while Soyuz is enroute to ISS monitor the following frequencies:
121.750 Mhz (Soyuz/ISS ranging/docking and FM voice)*, 130.167 ISS (ranging/docking), 143.625 ISS, 166.000 Soyuz/ISS, 259.700 STS ISS Crew/payload transport AM voice
Zariya Russian Spaceflight
NASA Soyuz timeline