To: Win Smith who wrote (411 ) 2/4/2003 11:55:26 AM From: Win Smith Read Replies (2) | Respond to of 603 Now, the Space Station: Grieving, Imperiled nytimes.com [ What a mess. The space station was actually the first thing I looked up on Saturday, but I couldn't easily find any reference to whether it was even currently manned. Which of course it is. I've never been a fan myself, way too expensive. ] The grounding of the three remaining space shuttles after the destruction of Columbia poses enormous, and potentially calamitous, challenges for the International Space Station and the 16 countries trying to maintain it as a permanent foothold in space. All of the shuttle launchings scheduled for this year and early 2004 were missions to ferry crews or components to the station, which has been under construction since 1998. Now this schedule is in total disarray. If delays persist for a year or more, some experts says it may even become difficult to prevent the station from falling into Earth's atmosphere. Until now, occasional nudges from the shuttle have helped keep it from sinking under the tug of friction as it skims the outermost ether. . . . Perhaps the biggest question, if the delays persist, is how to keep the 200-ton device — as capacious as a three-bedroom house — from sinking out of orbit altogether and incinerating as Columbia did. It has been routine for each shuttle that delivers a fresh crew or the latest truss or module to boost the expanding assemblage about eight miles upward, countering the steady sinking caused as the station's broad surfaces encounter drag exerted by diffuse molecules of air. The Russian Progress spacecraft can haul fuel to boost the station, as well, but they will not be visiting nearly enough this year to compensate for the absence of space shuttles, five of which were to have docked before 2004, including one in November that would carried a teacher, Barbara Morgan. The station has its own store of propellant to keep properly positioned, but even those supplies could be depleted eventually, space experts said. This leads to the troubling calculus about keeping the station in space, said John E. Pike, a space technology expert and director of globalsecurity.org, a Washington research group. "Everybody's going to be looking closely at the inventory of Progresses and Soyuz boosters to put them up, and running that against the need to reboost the station," Mr. Pike said. "Maybe the answer is that there's more than enough, or just enough, or more than enough for this year, but after that there's a real problem." He said that if the Russian craft could not fill the bill, NASA might have to try to cobble together a tanker of some sort. If the station is not continually boosted higher into space, though, he said, trouble will be inevitable, and will intensify the lower the station drifts. "The lower you go, the less time you've got," he said.