The Washington Post November 9, 2003
Perilous Balancing Act in Space; Columbia Creates Ripple Effects for The Space Station
By Eric Pianin and Kathy Sawyer
In the nine months since the calamitous breakup of the space shuttle Columbia, NASA has struggled to strike a perilous balance aboard the international space station, weighing the risks of keeping an undersupplied two-man crew on the $ 30 billion space laboratory against the danger that the 206-ton facility could spin hopelessly out of control if it is left unmanned.
From the moment of Columbia's destruction, NASA and outside experts have worried about operating the unfinished orbiting complex without the workhorse space shuttles to ferry up tons of supplies and new components and to take away waste. As the prospect grows that the shuttles will remain grounded well into 2004 and more components aboard the station break down in the harsh environment of space, balancing the equation has grown steadily more difficult
On Thursday, NASA unveiled an 84-page plan for applying the recommendations of the Columbia Accident Investigation Board to the management of the orbiting facility. Among other things, it said space station employees are reviewing more than "700 waivers, deviations and exceptions" to the space station program's written requirements to see whether there has been "an accumulation of accepted risk over time" -- a much-criticized tendency in NASA's spaceflight culture that investigators concluded had contributed to the shuttle accident.
The review is focusing especially on the exceptions "that carry safety risks of a catastrophic nature," the NASA report said, adding that the effort may lead to modifications in the space station itself or changes in the requirements.
"There is a lot going on. This is a very difficult time. Space is hard," said Michael Kostelnik, NASA's chief of human space flight, at a headquarters briefing on the challenges faced by the United States as well as its international partners in the project.
As far back as March, internal studies warned of a host of dangers for six separate systems, including the thermal controls that cool the station's computers and interiors, that would likely grow out of trying to run the station with limited supplies and a caretaker crew of two instead of the normal complement of three. NASA said the astronauts have learned to overcome many of those obstacles in the months since then, but other problems have festered or grown worse.
Later this month, NASA and its international partners will have to make a particularly difficult decision whether to proceed with a spacewalk in February that would place both crew members outside the facility with no one left inside. The European partners are eager for the spacewalk to begin preparing the station's exterior for the arrival of their new unmanned space cargo vehicle next year, and the Japanese want to retrieve scientific experiments that took advantage of the weightlessness of space.
But critics say that with both crewmen outside, there would be no way for the two astronauts to respond quickly to unexpected problems, such as a freeze-up of onboard command and control computers that operate virtually every system on the station, a power failure, or a sudden shift in the space station's orientation or "attitude." A NASA engineer familiar with risk assessments noted that in recent years, the system's command computers have experienced periodic glitches that required manual rebooting.
During the spacewalk, there would be no one onboard to read or hear "caution and warning" signals, and there is a chance that ground controllers would temporarily be in the dark about any such problems because of the routine loss of signal between the station and mission control for 15 to 20 minutes of every 90-minute orbit. A NASA document said temporary loss of some hazard controls "can expose the EVA crew to greater risk."
Moreover, with no one onboard, there would be no one to help the two astronauts in an emergency, such as a tear in a spacesuit or difficulty repressurizing the airlock when reentering the space station.
A Johnson Space Center flight surgeon said last week that many in the space program regard plans for the spacewalk with disbelief, saying NASA should delay the extravehicular activity, or EVA, until the next replacement crew arrives, when there would be four or more astronauts aboard for several days. "Those of us who care for the astronauts don't understand why they're willing to take this kind of risk. What's so important that we have to do this now?" he asked.
John Pike, an independent space policy expert who heads Globalsecurity.org, said, "For the longest time, NASA has said they need three people to maintain the station. The notion you would be in a [spacewalk] situation with everyone on the outside and no one on the inside . . . strikes me as not giving them very much in the way of backup and redundancy."
Michael T. Suffredini, a top space station official, noted that the Russian space station Mir had a two-person crew that often conducted spacewalks with no one inside the facility, and that the NASA team can benefit from their experience.
NASA Administrator Sean O'Keefe and William Gerstenmaier, manager of the space station program, acknowledged that a preliminary review had indicated that the spacewalk entailed added risk. "We took a look at it from an overall cursory view to see if there were any major showstoppers that would prevent us from [doing the spacewalk], and we didn't find any," Gerstenmaier said in an interview last week.
The officials said they have commissioned a more exhaustive study of every facet of the six-hour spacewalk with the Russians to provide a basis for the decision on whether to go ahead.
"We do recognize that there are several failures that could occur that could cause [the] station to go into a loss of attitude," Gerstenmaier said. But he said that NASA engineers are attempting to anticipate every conceivable problem, and that there will be plenty of communication and tracking backup in the United States and Russia to make sure no crisis goes undetected.
"Loss of attitude control is not problematic," he said. "We just need to train crew to detect it while they're EVA. They can determine that the station is drifting fully out of attitude. There's no big hurry. No big rush."
After six months of experience with only two people onboard, NASA officials say they are increasingly confident that for more routine operations, the newly arrived crew can maintain the space station and carry on limited scientific research with little problem.
"I don't think there's any additional risk with a two-man crew versus a three-man crew," Gerstenmaier said, adding that earlier concerns have dissipated with time. "What we've seen through this actual mission is that our response time with [a two-man] crew is totally satisfactory," he said.
But since the shuttles were grounded, there has been a steady drumbeat of concern. "A lot of people work really hard to make this work well . . . but I just see this situation as one or two failures away from not flying people in space for a long time," said a NASA engineer who has specialized in risk assessment, speaking on condition he not be identified.
Since Feb. 1, Russian Soyuz and Progress rockets have had to take over the job of transporting crews and supplies to the space station. Those spacecraft carry much smaller payloads than the space shuttles. In September, Congress's General Accounting Office cited several resulting safety threats, such as delays in flying up added shielding to protect the station against space debris, in replacing a failed gyroscope -- one of four that keep the station stable -- and in analyzing the cause of the failure.
Also in September, Arthur Zygielbaum, then a member of a NASA safety panel, expressed concern that communications problems between the U.S. and Russian teams had caused a series of potentially serious incidents aboard the station, such as the premature firing of a Russian cargo ship's thrusters that triggered a "force fight" with the onboard flight controls. "My concern is that it's a progression" down a dangerous path, like the one that led a chunk of foam to bring down Columbia, he said last week.
A recent NASA study found that the risk of fire aboard the station has grown because the crew is stowing large quantities of supplies, equipment and waste in front of or near 14 portals that would be crucial for detecting and extinguishing a fire in any of the station's various compartments. There also is concern that a portion of the station's water stores supplied by the Russians may have high levels of carbon tetrachloride, a toxic contaminant.
The Washington Post reported Oct. 23 that NASA's decision to launch a new crew last month came over the strenuous objections of mid-level scientists and physicians who warned of deteriorating medical equipment and air, water and radiation monitoring devices. Some NASA medical experts and scientists argued that the station should be temporarily abandoned until the space shuttle fleet is flying again.
Although studies are underway for the reorganization of the spaceflight safety operation, Kostelnik said that there is no independent safety monitoring of the station operation by outside experts.
© Copyright 2003, The Washington Post
