— The international space station has been literally falling out of the sky, according to NASA tracking data obtained by MSNBC.com. Under the inexorable decay of air drag, its orbital path around Earth has slipped down to 207 miles (332 kilometers), the lowest average altitude in the nine-year life of the project. A small rocket engine on a docked cargo ship is being fired this week to boost the orbit by a small amount. But since the orbit is continually dropping at about 300 feet (90 meters) per day, the boost will be eaten up by the effects of air drag within several weeks. A graph released by NASA shows that the gradual decline began in earnest after the loss of shuttle Columbia in early 2003. Prior to that disaster, the altitude had been maintained at a fairly high level, thanks mainly to reboosts from visiting shuttles.

Since that event, all reboosts have been the responsibility of Russian spacecraft. Keihin Cr Special Carburetor Tuning Manual there. However alarming the line on the graph might appear to be, NASA orbital trajectory experts insist that the station's orbit is under control. They say the decline is part of a long-range plan for the current phase of orbital assembly that involves particularly heavy payloads for shuttle missions.