23 May 2003
23 May 2003
The chief investigator of the Columbia accident predicted Saturday that NASA eventually will be able to resume space shuttle missions.
Since the probe began in the hours after the orbiter fell out of the sky Feb. 1, Harold Gehman, the retired U.S. Navy admiral who chairs the Columbia Accident Investigation Board, has hammered the space agency about its management practices and safety oversight, and has been noncommittal in his views of what it will cost or how long it could take for the shuttle program to resume.
But his comments Saturday were the most optimistic yet about NASA's prospects of putting shuttles back in space. The panel is due to complete its formal report in late July.
""At this stage, the board has not come across any show stoppers that in our mind would prevent the shuttle from returning to flight,"" Gehman said as he and five other board members examined the Columbia wreckage that has been gathered at the Kennedy Space Center.
""Now, how high is the stack of return-to-flight items when we get finished? I can't tell you now,"" Gehman said. ""But right now, it looks manageable.""
Columbia's fatal breakup over Texas forced NASA to ground shuttles Discovery, Atlantis and Endeavour as well as to suspend what had been planned as an ambitious year of assembly for the U.S.-led international space station. Publicly, space agency officials have spoken of attempting to resume missions by late this year, but they privately acknowledge that it could be well into next year at the earliest.
The accident board's formal findings and recommendations are certain to prompt a reorganization of NASA's shuttle operations and safety oversight as well as modifications to the remaining spacecraft themselves.
Saturday's visit to the large hangar where an estimated 84,000 pieces of Columbia wreckage is being meticulously re-assembled and analyzed was the first for several of the board members since the panel declared a working hypothesis for the accident's cause late last month.
Investigators believe Columbia began its descent to Earth with a pre-existing breach in the leading edge of the left wing. The opening allowed a jet from the searing plasma cloud surrounding the shuttle at re-entry to invade the wing, triggering a thermal and structural failure. The board has not directly linked the breach to a chunk of foam insulation that struck the wing seconds after Columbia's Jan. 16 liftoff, but the strike remains the most plausible explanation.
""We get briefings continuously on what the debris and the metallurgy tells us. Many of us felt it was our duty to come down to see it for ourselves,"" said Gehman. ""We saw the things today which we believe are compelling pieces of evidence that tell us how the heat got into the vehicle and where the flaw started.""
The investigators spent much of their visit hovering over a three-dimensional reconstruction of Columbia's left-wing leading edge, particularly close to the fragments of the U-shaped carbon composite panels where they suspect the breach occurred. The left wing was armored by 22 of the panels, and experts suspect Columbia was struck by the foam close to the fuselage. The charring evident on recovered carbon components, the spattering pattern on the underside of the panels from the rapid melting of the aluminum wing spar, and evidence from thermal, stress and pressure sensors point to an initial breach between the eighth and ninth panels.
""There was more debris collected than we thought and the analysis of what was done at Kennedy turned out to be more significant to our conclusions than we would have guessed at the beginning,"" Gehman said.
In contrast, Max Faget, one of the United States' most important spacecraft designers, says the space shuttle, which he helped pioneer, should be retired and the human space program suspended until the nation can build a better vehicle for putting astronauts into orbit.
Similar calls for grounding the shuttles and other harsh assessments of its safety have been growing over the past week from members of Congress and space-policy experts who say the fleet is too unreliable, too old and too costly to continue operating.
But such views largely have represented critics outside the circle of elite space engineers.
Faget designed the Mercury space capsule and had a managing role in the design of every other U.S. human launch system, including the space shuttle, Apollo and Gemini. He has received almost every commendation that exists for engineers and was inducted into the Ohio-based National Inventor's Hall of Fame this year.
""The bottom line is that the shuttle is too old,"" Faget, 81, said Wednesday from his Houston-area home. ""It would be very difficult to make sure it is in good shape. We ought to just stop going into space until we get a good vehicle. If we aren't willing to spend the money to do that, then we should be ashamed of ourselves.""
The aerospace industry already is positioning itself for such an effort, industry sources say. Boeing is studying two options for building a derivative of the shuttle that could be rushed into service within three years.
Until then or until the shuttle flies, the National Aeronautics and Space Administration is relying on the Russian Soyuz capsule to get back and forth to the international space station.
Faget, director of engineering for human spacecraft design at NASA for 20 years, was blunt in his criticism of the U.S. reliance on the Soyuz.
""It is like going down the highway and thumbing a ride,"" he said. ""You can do it, but it isn't the best way to get around. It is really admitting defeat.""
NASA officials did not respond directly to Faget's comments, although they said the ""shuttle he designed 30 years ago is not the shuttle of today,"" noting it has been upgraded and modernized.
However, NASA engineers said privately that they regard Faget as ""a giant in the space community whose opinions are worth more than anybody else's.""
Roger Launius, chairman of the history division at the Smithsonian Air and Space Museum, called Faget's role in U.S. development ""very significant,"" noting it was his influence at the Johnson Space Center that led to the whole concept of a winged reusable spacecraft during the late 1960s when the shuttle program originated.
""He has had his finger on the design of every U.S. space vehicle,"" Launius said. ""His opinion matters. ... I would suspect there are a lot of people who agree with him.""
Whether the technology of the existing fleet should be updated or a new fleet of spacecraft built is the subject of an intensifying national debate about the U.S. human space program. At issue is how many billions of additional dollars the nation can afford for the program.
Faget feels the choices are obvious.
""We ought to get a decent vehicle. It could carry fewer people, but it ought to be a new vehicle.""
Current shuttles can carry seven astronauts, the most any spacecraft has transported, and its 60-foot long payload bay remains the most capable heavy space truck in existence.
For that reason, NASA said it needs the space shuttle to complete the space station.
Pending findings of the Columbia Accident Investigation Board review, ""NASA feels that the shuttle is still the most advanced, high-tech heavy lift vehicle in the world,"" said Robert ""Doc"" Mirelson, a NASA spokesman.
""Right now, the administration has set the priority of returning the shuttle to flight pending the findings. The shuttle is grounded and will stay grounded until we are absolutely certain it can return to flight safely.""
A number of past efforts by the agency to replace the shuttle have failed for technical, political or monetary reasons. Boeing has begun new efforts on its own to examine how quickly it could turn out a replacement spacecraft.
Mike Lounge, a former astronaut who is now manager for Boeing's NASA Systems in Houston, told attendees at the 40th Space Congress in Cape Canaveral last week that Boeing engineers were doing an ""internal exercise"" to determine the best way to construct a replacement shuttle.
Two options are under study, according to a source familiar with the studies. One would use old blueprints but adopt modern manufacturing techniques.
The other would build a modernized shuttle using the same ""mold line"" or shape of the current fleet but with the latest light-weight composite materials and advanced electronic equipment.
The source said Boeing believes it can build such a shuttle in three years, far less than the decade or so it would take to develop and build the orbital space plane that NASA envisions as the replacement for the shuttle.
The new vehicle also would cost significantly less, according to Boeing's internal projections, at about $2 billion, compared to about $10 billion for the orbital space plane.
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