As launch nears, NASA can't shake its worries
With top officials still raising safety questions, NASA can’t help but be uneasy about the July 1 launch of Discovery.
By CURTIS KRUEGER
Published June 20, 2006
Space shuttles have launched 114 times over 25 years, but they remain so experimental that “every flight is a test flight,’’ says NASA Director Michael Griffin.
That has never been more evident than now. NASA is moving forward with plans to launch the shuttle Discovery on July 1 even though the agency’s top safety official and chief engineer recommended against it during a preflight review over the weekend.
Griffin gave the green light despite the objections.
Bryan O’Connor, a former shuttle astronaut who is NASA’s chief safety and mission assurance officer, and Christopher Scolese, the chief engineer, are the only two people on a 25-member panel who recommended delaying the launch. They favor waiting for a redesign of the external tank, the giant orange torpedo-shaped structure that supplies fuel to the shuttle’s main engines
Still, both say they will not appeal the launch decision because new rescue options mean the astronauts’ lives will not be in danger.
The two say they are concerned about falling foam, which has proved a lethal problem before. Foam, which helps insulate the external fuel tank, fell during launch and damaged the shuttle, dooming the Columbia, which disintegrated during reentry and killed a crew of seven in 2003. After two years of re-engineering, more foam fell when Discovery launched last summer, though the shuttle returned safely.
Now the main concern is falling foam from ice-frost ramps, which cover brackets on the tank.
Griffin said the upcoming launch should not compromise the safety of the seven astronauts, six from NASA and one German from the European Space Agency.
But the explanation he gave served to show just how experimental the space shuttle program remains, even after a quarter-century and two disasters.
“The question is can we fly a few times with this ice frost ramp without probably incurring a hazard, and based on the data that I have seen, I believe that we can’’ Griffin said.
But if he’s wrong and Discovery is damaged during launch, new inspection techniques will allow the astronauts and mission staff to see it, Griffin said.
Then NASA could try a new rescue option -- so new it was not even on the books until last summer’s Discovery flight. The astronauts could wait at the International Space Station for another shuttle, the Atlantis, to rescue them.
“I certainly would have to think harder about putting a crew on this vehicle if I thought we didn’t have the Space Station safe haven,’’ Griffin said.
It’s also possible, Griffin said, that NASA could rely on the Russian Soyuz spacecraft to rescue them.
But these rescue options probably would involve abandoning the Discovery, and perhaps the space shuttle program itself.
After an incident like that, “I would not wish to continue with the program,’’ Griffin said.
O’Connor and Scolese said they do not object to Griffin’s decision to launch.
“We do not feel... these issues are a threat to safe return of the crew,’’ the two said in a statement. They said NASA engineers hashed out differing points of view and “the agency is accepting this risk with its eyes wide open.’’
O’Connor told the Associated Press that he and shuttle program manager Wayne Hale, who have spent decades together in the program, said they could not recall a time when a launch proceeded over the objections of the safety office.
Ten years ago, O’Connor quit as chief of the space shuttle program over a reorganization he said would threaten crew safety. But he said this disagreement was not nearly as worrisome: “I wasn’t anywhere close to that.’’
Bill Engblom, an associate professor at Embry-Riddle Aeronautical University, said the discussion reflects the real risks of space flight. “In this case I would have been truly surprised if there was no dissent.’’
The problem facing Griffin and others is that because of the complexity of the shuttle and space flight itself, many important questions, such as the danger of foam falling from ice frost ramps, don’t have good answers, Engblom said.
“It’s such a complicated machine,’’ said Engblom, who served on a NASA Engineering Safety Center review team following the Columbia tragedy.
Paul Czysz, professor emeritus of mechanical and aerospace engineering at St. Louis University, said Griffin, whom he knows, is faced with the reality that there is no space flight without risk. He said he thinks Griffin is right to move toward a launch, especially because a rescue option is in place.
“It’s not like Evel Knievel trying to jump the Grand Canyon... this isn’t that kind of risk.’’
After the Columbia accident, NASA was criticized as being a place where the corporate culture prevented open discussion of problems. The comments of O’Connor and Scolese at least shows that people are speaking up.
Another criticism that has been made of NASA in the past is that it was so worried about keeping up the number of scheduled flights that it dropped the ball on safety. Although safety is certainly on the mind of NASA’s top administrators, so is the schedule.
The space agency wants to finish building the International Space Station by 2010, which would require about 16 more flights.
Because the shuttle has flown only once in the past three years, meeting that schedule will not be easy.
Curtis Krueger can be reached at firstname.lastname@example.org or (727) 893-8232.
[Last modified June 20, 2006, 22:23:04]
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