By Marc Kaufman
Washington Post Staff Writer
Sunday, January 6, 2008
NASA's plan to increase the number of space shuttle flights it launches this year, in an effort to speed up final assembly of the international space station, has stoked concern among independent experts that the space agency is placing scheduling demands on the 27-year-old fleet similar to those that contributed to the Challenger and Columbia disasters.
NASA has scheduled six shuttle launches this year -- twice the number of flights it managed in each of the past two years -- but that plan has already been complicated by the grounding of the shuttle Atlantis as the result of a recurring electrical problem.
Although NASA has many new safety procedures in place as a result of the Columbia accident, the schedule has raised fears that the space agency, pressured by budgetary and political considerations, might again find itself tempting fate with the shuttles, which some say were always too high-maintenance for the real world of space flight.
NASA officials say they remain confident that the three spacecraft will complete their schedule of 13 flights by the time the shuttle program is due to shut down in September 2010. Officials also say they will finish assembly of the space station, which they say will be a historic achievement for mankind.
William H. Gerstenmaier, who has been with the shuttle program since its inception and is now NASA's chief of space operations, acknowledges that flying the shuttles has driven home time and again just how difficult it is to send men and women into space.
Nonetheless, he said that, despite their age, the shuttles are safer now than ever because NASA has learned so much more about flying them. The orbiters themselves remain in good shape, Gerstenmaier said, and the fleet -- which has flown 120 missions -- could continue flying beyond 2010 but for financial and logistical considerations imposed by the effort to build a new generation of spacecraft. The shuttle cannot fly beyond low Earth orbit, and President Bush has called for a renewed effort to explore the moon and later Mars.
"The schedule we've made is very achievable in the big scheme of things," Gerstenmaier said of the remaining flights. "That is, unless we get some unforeseen problems."
The history of the program, however, is filled with such problems -- including a rare and damaging hailstorm at the Kennedy Space Center last year as well as the shedding of foam insulation that led to the destruction of Columbia and its crew in 2003. The 2 1/2 -year hiatus in launches that followed that disaster has already reduced the number of missions scheduled to the space station, and as a result several important and expensive instruments built for it -- including one that cost European researchers $1.5 billion -- now have no way to get into space.
"This pressure feels so familiar," said Alex Roland, a professor at Duke University and a former NASA historian. "It was the same before the Challenger and Columbia disasters: this push to do more with a spaceship that is inherently unpredictable because it is so complex."
The shuttle's complexity is undisputed and proudly proclaimed on the NASA Web site. With room for seven astronauts, a large cargo bay and airplane-like wings that allow it to glide back to Earth for landing, the shuttle can do much more than any other spacecraft in history. But that complexity has also made it subject to innumerable mechanical problems and weather delays -- the kind that seldom trouble the Russian Soyuz program. As Gerstenmaier described it, the Soyuz capsules can easily be launched in winds and other weather that would keep the shuttle earthbound, and they float back to Earth under parachutes like the earlier Apollo capsules.
The panel that investigated the 2003 Columbia disaster addressed the issue of complexity and concluded that it made the shuttle inherently experimental and risky. As a result, some want to see the shuttle grounded as soon as possible. Panel member John Logsdon, a space policy analyst at George Washington University, said another fatal failure must be avoided at all costs, both for the potential loss of life and because it would probably end the manned space program for many years.
"Every time we launch a shuttle, we risk the future of the human space flight program," he said. "The sooner we stop flying this risky vehicle, the better it is for the program."
The problem currently grounding Atlantis involves four backup fuel sensors at the bottom of the massive external tank that carries the shuttle's super-cooled hydrogen fuel. In December, NASA twice scrapped scheduled launches of Atlantis because the sensors were malfunctioning, and late last month engineers took some parts out of the tank and sent them to another NASA facility for analysis.
Officials said last week that they are almost certain they know what was going wrong and penciled in Jan. 24 as the first possible day for Atlantis to fly. But they said they doubted the sensor problem would be fully resolved by then and were more confident that the fuel tank would be fully operational by early February.
At that point, however, the shuttle would run into a different problem: A Russian Progress cargo ship is scheduled to dock at the space station on Feb. 7, and only one spaceship can dock at a time. Further delays for Atlantis could be the result.
Gerstenmaier said that despite these obstacles, it is entirely possible for NASA to launch six shuttle flights in 2008. He pointed to a five-month period in 2007, when three launches went off trouble-free, as an indication of what was possible, absent unforeseen problems.
While the mechanical, weather and logistical delays have proved costly and time-consuming, Gerstenmaier said they also have had a silver lining: They have provided invaluable experience in fixing problems on the run that will pay large dividends in future space travel.
"In our world, we're often dealing with risk versus risk situations, and there's no better training than working through problems as they occur," he said in an interview, likening the difficulties faced by the shuttle to those inherent in all exploration. "When we have a string of successes, I get nervous because people begin to think this is easier than it is. . . . They let their guard down about the high level of risk."
NASA is also facing growing political pressure to keep the shuttles flying beyond 2010, especially from lawmakers who represent NASA workers who could lose their jobs after the shuttle program ends. Thirty-two members of the Texas congressional delegation sent a letter to President Bush last month asking for at least one additional shuttle flight, and Rep. Dave Weldon (R-Fla.) introduced a bill that would provide funding to speed up construction of the new spacecraft while requiring the shuttle to continue flying to the space station until 2013.
"There is absolutely no reason to believe that a shuttle launched in early 2011 will be any less safe than one launched before that September 2010 deadline," said Weldon, who represents the area around the Kennedy Space Center at Cape Canaveral.
"That's just an arbitrary cutoff that will harm the space program and will make it so any American astronauts going to the station for four or five years will have to go from Baikonur," the Russian launch facility. "To me, this makes no sense at all."
NASA Administrator Michael D. Griffin has strongly opposed efforts to fly the shuttle beyond 2010, saying that continuing the program would cost more than $2 billion a year that should instead go into building the new Constellation spaceship.
For the shuttle program, the next 2 1/2 years will be a sprint. When the most intensive work was being done on the space station between late 2000 and early 2002, NASA launched a shuttle every two months, on average. It would need to average a launch every three months until September 2010 to make the deadline, while dealing with many additional post-Columbia safety procedures and protocols.
Duke professor Roland said that based on the shuttle program's history, he sees virtually no possibility of NASA completing 13 flights by the deadline. He predicted that the agency would ultimately cut some of the launches but still declare the space station completed.
"NASA is filled with can-do people who I really admire, and they will try their best to fulfill the missions they are given," he said. "What I worry about is when this approach comes into conflict with basically impossible demands. Something has to give."