Like an ornament on a tether, the International Space Station (ISS) is making passes across the evening sky now through the end of the year from many locations in the northern hemisphere. You can watch for it at dusk from almost anywhere; unlike many celestial objects, the ISS can even be seen from the downtowns of light-polluted cities.
Ground control and astronauts are working to correct a recent malfunction in one of the station’s two cooling loops responsible for dissipating the station’s excess heat. The loops circulate ammonia outside the space station through giant radiators to keep the station cool. Besides heat from electronic equipment, the ISS experiences temperatures on its hull of 200 degrees when it’s exposed to the sun.
As they figure out how to fix it, a second unit is working properly and the astronauts are safe. Mission managers have deferred the decision on whether to proceed with or postpone the launch of the Cygnus commercial cargo craft until more is known about the cooling problem. Cygnus is currently scheduled to launch Dec. 18 from Wallops Flight Facility in Virginia and rendezvous with the station on Dec. 21, according to NASA’s ISS website. To learn more about how the space station keeps its cool, click HERE.
The space station moves from west to east across the sky and takes from a couple to five minutes to make a complete pass. You might notice it has a yellowish color – that’s from sunlight reflected from its eight sets of solar panels.
* Today Dec. 14 starting at 6:10 p.m. Bright, high pass to 66 degrees altitude after which it suddenly will fade upon entering Earth’s shadow
* Sun. Dec. 15 at 5:22 p.m. Brilliant pass straight across the top of the sky. The ISS will shine at magnitude -3.3, just one magnitude fainter than Venus
* Mon. Dec. 16 at 6:11 p.m. across the northern sky. Max. altitude: 41 degrees
* Tues. Dec. 17 at 5:22 p.m. high in the north. Max. altitude: 51 degrees
* Weds. Dec. 18 at 6:11 p.m. across the north. Max. altitude: 34 degrees
* Thurs. Dec. 19 at 5:22 p.m. across the northern sky. Max. altitude: 37 degrees
* Fri. Dec. 20 at 6:11 p.m. in the north. Max. alitude: 36 degrees