This area was not investigated when the shuttle was still in orbit * The object itself was also not observed except in retrospect when 3,100 radar images were examined * A difficult question - why does NASA not have real-time intelligence?
An object seen hovering near the shuttle Columbia on its second day in space is almost certainly a reinforcement panel from the outer left wing. This is according to testimony given to the commission of inquiry by Brigadier General John Barry, a member of the commission of inquiry into the Columbia disaster.
The lack of the panel created a weak spot on the wing, through which the hot gas could enter the shuttle as it made its way into the atmosphere. However, the researchers said that additional analyzes are needed, and it is too early to focus the entire disaster on one and only one panel.
"You are way ahead of us if you blame the panel," says the chairman of the investigative committee, Harold Gehman, a retired admiral. "We have no way of concluding that we found here the initial event that caused the disaster."
The object was actually discovered only after the accident, when senior officials at the US Space Command began to examine the 3,100 observations made by radars during the 16 days of the mission. Tracking of the object showed that it re-entered the atmosphere, burning up over the Pacific Ocean. The left wing was damaged by shrapnel during Columbia's liftoff on January 16, when a large piece of insulation foam broke free from the shuttle's huge external tank and collided with the left wing.
NASA investigated the foam incident during the mission but concluded that it did not represent any safety risk. However, ongoing analyzes since the accident have resulted in greater accuracy both in the size of the foam block and in the exact area where it hit.
Team members said the latest evidence of the impact of the fragments is centered on an area about 60 centimeters wide near reinforcement panel No. 6 - one of 22 panels covering the left wing tip. Two other thematic panels were also apparently damaged. This area was not tested in the analyzes done during the mission. In addition, team member Roger Teterlot said the size of the foam block is now estimated to be about 60 centimeters long, about 40 centimeters wide and 12 centimeters thick, slightly different from earlier estimates. In the coming weeks, the researchers plan to start shooting blocks of foam on panels and rails identical to those on the ferry to see what damage they suffered from the impact. Barry said that close examination of the panels on the three remaining shuttles revealed that they had small holes in their surface. These "stab" holes are repaired if their size exceeds a millimeter but the small defect could have weakened the panels.
He said that the holes are formed when zinc flutters from unpainted parts of the launch facility when the shuttle is on the pedestal (and sometimes these are long periods of waiting for flight) - then this zinc corrodes the carbon fabric of the panels.
Barry said that NASA was aware of the problem but added. "I don't think she got the attention she's getting now in the shadow of the disaster."
Thin holes caused disaster?
Chips of paint from the shuttle's launch tower may have splashed along with rain on the Columbia and created pin holes in the leading part of the left wing that contributed to the disaster, the investigative team says.
Such wear and tear may over the years lead to a weakening of the carbon panels along the edge, enough to break when struck by the foam shards during launch.
"We are examining the effect of age," said the chairman of the committee, Harold Gehman. Air Force Major General John Barry said that holes in the carbon padding lining at the edge of the wing may have allowed air pockets to form. The air gnawed at the coal in a process of oxidation.
It seems that such blacks were created in all four shuttles. NASA sealed the larger holes, but did not thoroughly check whether air pockets had formed, the investigation committee says.
Such pinholes were discovered on the Columbia in 1992, after 12 cruises and later appeared on other shuttles. According to Barry, 20-40 such holes have formed in each coal panel over the years, almost certainly as a result of zinc dripping from the paint of the metal tower that surrounds the shuttle and protects it from falling on each side of the launch pad.
Because this structure is not repainted and refurbished after each launch, more and more primer is exposed and whenever there is rain, corrosive oxidized zinc seeps into the shuttle, Barry says.
The days of these launch pads date back to the Apollo era, and significant parts of the infrastructure were never replaced because a decision was made that we could continue with them in launching spacecraft that have not yet been manufactured, said Barry, infrastructure should also be part of our investigation.
Barry says that NASA was aware of the problems with this leak, but commented: "I don't think the agency has given it the attention it deserves, so it is now, naturally, overwhelmed by the accident."
NASA recognized the problem of the oxidized zinc sprays sprayed on the tip of the shuttle corroding the materials, Gehman said.
The question is again, as in everything related to NASA: who is the most senior who knew?, is this seriously discussed? Has anyone looked at age as a weakness? We don't know that now, Gehman said.
The investigative committee stressed that the leakage of the foundation paint has the potential to explain the existence of the holes. However, there is also the possibility that salt spray from the nearby Atlantic Ocean created the holes. Columbia, NASA's oldest shuttle spent a total of two and a half years on the launch pad.
At the weekly press conference, investigators also said they found additional defects in the shuttle's spare fuel tanks, including problems with the connection of the insulation foam.
The external fuel tanks are being tested at the Michoud assembly facility in New Orleans, and it was found that there were 32 air pockets in the foam in the triangular area connecting the spacecraft to the tank, Barry said. This is where a foam weighing 900 grams - 25 inches long, 15 inches wide and 5 inches thick - broke and hit Colombia during the launch.
Air pockets like this, most of which are 5-8 centimeters in size, can cause the foam to tear. Pieces of foam from this area were not properly attached to the tank, Barry said.
As for the mysterious object seen floating away from Columbia one day after launch, it is now almost certain that it was a panel carried off the lower edge of the left wing leading edge. The one meter to one and a half meter long section connects the coal on the leading edge to the thermal tiles that cover the rest of the wing.
The Air Force Command discovered the bone using radar but did not know this until after the disaster on February 1. Shortly before the object appeared out of nowhere, the shuttle performed an orbital maneuver that almost certainly caused the part that was loose to come loose.
The absence of one panel could be enough to allow hot, deadly gases to enter the spacecraft during re-entry into the atmosphere and burn up the wing, said investigation team member Roger Tetralot, an executive who has worked on nuclear submarines. However, he said that a crack in the front of the left wing may also involve the carbon panels, gaskets, stainless steel supports and possibly even bolts.
For news in the Baltimore Sun
