Crowded Shuttle Schedule Sparks Worries
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.