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By Traci Watson, USA TODAY
Like many home-improvement projects on Earth, NASA's most ambitious building effort in space languishes half-done. Now new delays, combined with the space shuttle's looming retirement, are raising worries about whether it can be finished at all.
The International Space Station, a $100 billion orbiting laboratory, has been under construction since 1998. The station's pieces can get to orbit only on the shuttle, a fragile, aging vehicle that has suffered repeated schedule disruptions: •In the latest major setback, a glitch in a shuttle fuel gauge delayed a mission scheduled for early December. NASA says it hopes to launch the mission — to add a European laboratory to the station — on Jan. 24, but a February launch is more likely. •A hailstorm last February so badly dented a shuttle sitting on the launch pad that liftoff was postponed three months. •The disintegration of shuttle Columbia in 2003, which killed the crew, led to a 2½-year hiatus in shuttle flights. Technical problems during the first flight after the accident led to an additional one-year delay. Even a few months' delay in a shuttle flight is cause for concern, because the shuttle must retire by October 2010 to free up money for developing a safer vehicle. The spacecraft is slated to fly 13 more missions before it rolls into its hangar for good. That's an average of nearly five flights per year, a rate NASA hasn't achieved since 2002. Already shuttle managers have said that a flight scheduled to blast off Feb. 14 to deliver a storage room to the station will have to slip deeper into 2008 because of the fuel-sensor delay. "They still have a good shot at it," Tommy Holloway, a former station program manager, said of NASA's chances of completing the station. "But runway is running out," he added, using an aviation expression. Others are more pessimistic. "It's certain" that the shuttle won't be able to pull off all 13 flights before late 2010, says Vincent Sabathier, a former European Space Agency official now at the Center for Strategic and International Studies. "It's an aging system. … And delays are the nature of the game in space launches." NASA officials say they have no doubts that the shuttle can finish the job before the clock runs out. The agency's chief of space operations, William Gerstenmaier, pointed out last month that the shuttle blasted off three times within six months in 2007, showing that NASA is capable of pulling off the necessary flight rate. Holloway notes that because of the loss of Columbia, NASA now has only three shuttles to fly missions. When there were four or more shuttle flights per year in the 1990s and early 2000s, the agency had four shuttles. A more intangible factor also is holding back shuttle launches, Holloway says: greater caution and awareness of safety in the wake of the Columbia accident. That's "appropriate," he says, but can also lead to more delays. Flights in the next few years will add a Japanese lab and more living space to the station and will fix the Hubble Space Telescope. The last flights on the shuttle's to-do list will carry crucial supplies to the station, including spare parts. If those parts are not delivered, a breakdown on the station could threaten its survival. "We need to fly those flights," Gerstenmaier told a congressional committee last year. He said in December that NASA has "six backup plans in our hip pocket" if the shuttle fails to complete its assigned missions, but he declined to reveal the specifics. The station is scheduled to remain in operation through at least 2016. Crews would come and go every few months on the shuttle, until it retires, and on a Russian spaceship. NASA originally had hoped to fly six shuttle missions in 2008. The schedule left little room for anything going wrong, says Raymond Colladay, a former NASA official. The new wave of delays "is a red flag," he says. "This is going to be a pretty telling year."
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