"700 Waivers, Deviations And Exceptions"
When the space shuttle
Columbia disintegrated over Texas February 1st, the single
program most immediately affected was the International Space
Station. So dependent on frequent shuttle flights for replacement
parts and personnel, as well as new equipment and waste retrieval,
the $30 billion ISS has been living on the edge.
The three-person crew has been reduced to two. That saves on
supplies, but doesn't do anything to replace the equipment already
onboard when it fails. The shuttles won't fly again until at least
late next year. So what if something breaks?
The ISS crew has a way back to Earth, of course. There's an
emergency taxi waiting for them just outside the door. But before
the shuttles fly, will there come a time when the risks simply pile
up beyond acceptable levels?
As the Washington Post reports, NASA last week released
an 84-page report on the implementation of recommendations from the
Columbia Accident Review Board (CAIB). ]
It says NASA employees are now going over a growing list of more
than "700 waivers, deviations and exceptions," hoping they won't
find reason to repeat one of the most stinging criticisms of the
shuttle program: an "accumulation of risk over time."
With a long, hard glance
back in time to last February, they're looking for issues "that
carry safety risks of a catastrophic nature," the NASA report said.
Depending on what they find, there could be changes to
modifications in the space station itself or NASA could simply
change the rules.
In essence, NASA engineers and scientists are looking at six
different systems, identified less than two months after the
Columbia disaster, that could wear out, break down or
become depleted. In a striking resemblance to the Russian Mir
project in its later days, the ISS crew has already been forced to
implement workaround measures to some problems. But there are
others where the crew has barely held ground and there are issues
that have grown worse.
The More Things Change?
Case in point: ISS managers have until February to decide on a
spacewalk that will require both crew members to be outside the
station at the same time. Both crew members. As in, no one left
inside. They're supposed to make ready for the arrival. They have
to consider contingencies like, what happens if the command and
control computer malfunctions or even locks up? The entire station
is run from that one system. It's recently developed a reputation
for periodically displaying the ISS equivalent of the "blue screen
of death."
What happens if the power goes out? What about sudden and
unexpected changes in the station's attitude? Who'll watch for
trouble ahead by monitoring the station's essential systems? What
happens if problems develop with the airlock?
A lot of things can go wrong in the span of a six-hour
spacewalk.
The Post reports a flight surgeon at Johnson Space
Center was aghast when he heard of the plan. The paper quotes him
as saying, "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?"
Space station manager William Gerstenmaier, along with NASA
Administrator Sean O'Keefe, acknowledges the two-man spacewalk
would increase the overall risk. "We took a look at it from an
overall cursory view to see if there were any major show stoppers
that would prevent us from [doing the spacewalk], and we didn't
find any," Gerstenmaier told the Post earlier.
"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
figures that's not an unrecoverable problem.
It's been six months since the ISS team switched to a two-man
crew and NASA officials say they're a lot more confident about what
they can do without the third crew member.
"I don't think there's any additional risk with a two-man crew
versus a three-man crew," Gerstenmaier told the Post.
"What we've seen through this actual mission is that our response
time with [a two-man] crew is totally satisfactory," he said.
But time is considered one of the station's worst enemies.
Things wear out. And the current schedule of Progress launches just
aren't enough to keep pace. Essential repairs may become critical
repairs before parts can be sent up on the Russian resupply rocket.
Two months ago, Congress's General Accounting Office said the
situation has caused a number of safety issues, including:
- delays transporting more shielding to protect the station
against debris floating in space
- Failure to replace a failed gyroscope -- one of four that keep
the station stable
- Failure to analyze the cause of the gyro failure.
- a power-distribution box that failed to meet requirements for
vibration endurance
- a robot-arm workstation which, as installed, has wires smaller
than specified
- radiator glitches
- problems in the onboard heart defibrillator
If that's not enough, the Post reports there's a
growing fire danger. With trash piling up and Progress flights
infrequent, some of the fire detection and extinguishing ports are
blocked by stowed equipment and debris. The Post also
reports concerns that a portion of the water supply may be
contaminated with carbon tetrachloride. That's a bad thing.
Given that NASA's own mid-level scientists objected to the idea
of this ISS mission in the first place, there now calls for
abandoning the space station until the shuttles fly again, almost a
year from now.