Posted on 02/16/2003 7:05:29 PM PST by conservativecorner
(CBS) The space shuttle Columbia's last major overhaul — the largest in the history of the program — involved some components and systems now under suspicion in the investigation into the orbiter's final, disastrous descent.
No evidence has emerged linking the work performed on Columbia during the 17-month refurbishment to the shuttle's breakup Feb 1. Columbia flew one successful mission after the overhaul was completed in 2001.
However, inspection and work records from that overhaul at the Boeing Co. plant where the shuttle was built in Palmdale, Calif., may hold clues.
Among the modifications to NASA's oldest shuttle were increased protection from space debris and enhanced heat protection for the leading edges of the wings.
According to NASA, the spacecraft's aluminum frame also was closely inspected for signs of fatigue or corrosion. It's not clear, and NASA officials could not immediately say, what was found and how much repair work took place.
The shuttle's first layer of protection, the fragile reinforced carbon tiles, also were closely inspected and repaired or replaced where necessary.
Disaster investigators have said they believe a hole or gash allowed superheated gases to penetrate Columbia as it entered Earth's atmosphere. They don't believe overheating detected in the left wing before the breakup could have been caused simply by the loss of tiles. Other possible causes include space debris or the impact of a piece of hard insulation that broke off the external tank shortly after launch.
During the 1999-2001 overhaul of Columbia, much of the emphasis was on wiring. In its last mission before the overhaul, July 1999, a worn wire caused a power fluctuation that led two engine controllers to shut down five seconds after launch. Backup controllers took over automatically and the flight was not affected.
About 95 percent of the shuttle's 235 miles of wire was inspected, including wires that connect to the sensors that eventually reported higher-than-normal temperatures just before the shuttle broke apart.
Technicians alqo(semoved 1,000 pounds of old wiring and equipment used to monitor Columbia's earliest flights 20 years ago.
During the overhaul, an independent board reviewing safety measures noted metal shavings in the shuttle, on walking platforms and wire bundles.
"These occurrences are considered potential sources of foreign object debris and could damage surrounding wire insulation or provide an electrical shorting path," the report said.
Henry McDonald, the report's lead author and former director of NASA Ames Research Center, declined to comment.
A Palmdale Boeing employee, who asked not to be identified, said there also were many "stumble-ons," or instances when technicians happened upon something needing repair. But he was unaware of any case in which a problem was not resolved.
In March 2002, Columbia's first launch after the work was done, NASA considered aborting the mission because of a problem with coolant lines. It was later determined the problem stemmed from debris left during the overhaul.
As has often been the case with the shuttle program, the Palmdale project was both behind schedule and over budget. It lasted 17 months instead of the expected nine and cost $145 million instead of $70 million.
Even after Columbia was shipped back to Kennedy Space Center in February 2001, it underwent several more months of work until the March 2002 launch.
Al Feinberg, a NASA spokesman, said wiring work was the reason for the delay and it was not unusual for work to be finished at Kennedy.
Dan Beck, a Boeing spokesman, wouldn't discuss details about why the job took so long.
"Because of our firm commitment on safety for our flight crews and the vehicles, we weren't going to be tied to any specific timetable to complete that work if there were still some outstanding areas that needed the attention of the maintenance and modification crew," he said.
Officials of United Space Alliance, NASA's prime shuttle contractor of which Boeing is a part-owner, did not respond to written questions.
NASA says shuttles receive major overhauls once every three years. Until 2001, that work took place at Palmdale, about 60 miles northeast of Los Angeles. NASA and the United Space Alliance announced after Columbia left Palmdale that all future overhauls would take place at Kennedy.
To: bonesmccoy
I have already posted my "bias" against Palmdale earlier in this thread - I have seen their work.
But you seem reluctant to even discuss the possibility that the workers in Palmdale might have caused some hidden damage to the leading edge of the wing when Columbia was there for OMDP. Is there some reason why this subject is "off limits" on "your" thread?
And excuse me very greatly for adding a piece of information that "you and XBob weren't talking about". My mistake.
Putting it another way, is this thread a search for the truth, or just a vanity thread?
1972 posted on 02/15/2003 3:54 PM EST by snopercod
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To: bonesmccoy
Pointing a finger at OMDP seems ridiculous because the vehicle had already flown one mission after OMDP and prior to STS-107.
Oh, so raising a legitimate question is now "finger pointing"? My original question was "Were the RCC leading edge sections removed and reinstalled in Palmdale?" Why do you find that question threatening?
The subject is...not reasonable because the vehicle flew an entire mission and had the inspections involved at KSC after OMDP.
I have no knowledge that the RCC leading sections were removed for inspection at KSC. That's why I was asking the question. Removing the tiles just aft of the RCC sections in order to inspect the inconnel attachment hardware is a major undertaking, as you might imagine, and if it had been done at Palmdale during OMDP, then almost certainly it was not done again at KSC.
Are you saying that if some attachment hardware were not intalled properly, then it would have to fail on the first flight, not the second? Certainly, if you have any familiarity with mechanical systems, you know better than that.
How can you insinuate in good conscience that a hairline crack could exist and be created by Boeing at Palmdale given all of the dynamics we have already discussed?
I didn't insinuate any such thing. What I did question was whether the RCC attachment hardware could have been installed improperly at Palmdale.
It is sometimes laughable that our national space program begins to hassle with regional political views (negatively impacting our program as a result).
Oh, I agree completely. Congress funded a study to determine whether it was safer and more cost-effective to perform the OMDP at Palmdale or at KSC. The report concluded that KSC was the cheaper of the two, and safer for the shuttle, since it didn't have to be ferried across the country twice.
But thanks to Congressman Sensenbrenner holding the funding for ISS hostage, OMDPs are still done at Palmdale.
1984 posted on 02/15/2003 4:28 PM EST by snopercod
[ Post Reply | Private Reply | To 1975 | View Replies | Report Abuse ]It's good to be the king...
I'd say their "enhanced heat protection" mod didn't work all that well.
You have done a great job of analysis over on "your" thread. But frankly, you have gotten married to your thesis to the exclusion of all other evidence.
The fact that a major modification was made to Columbia's leading edge RCC in 1999 should pique your interest, regardless of where it was done.
But apparently not.
Inconnel is a 70% nickel alloy. It looks just like stainless steel, but it has only 6% Iron in it. It is even farther down the galvanic scale from Aluminum than Iron, so theoretically, electrochemical corrosion would be more of a problem.
Also, I understand that you can get galvanic corrosion from carbon fibers (like in fiberglass airplanes), but have no knowledge of that.
Are you sure you want to dismiss the modifications to the leading edge as a contributing factor even before you know what they consisted of or why they were done?
Exerpt from Corrosion suggested in shuttle crash by James Oberg posted at MSNBC.
HOUSTON, Feb. 9 — Undetected corrosion that had weakened Columbia’s left wing could be the still-sought “missing link” between the otherwise-harmless debris impact during launch and the eventual vehicle loss during descent, a veteran shuttle engineer claims.~~~~~snip~~~~~
The bolts were made of Inconel 718 alloy and of A286 corrosion-resistent steel (CRES), and they were not affected. But the structure, fabricated from 2024 aluminum honeycomb, did corrode when salt spray from the nearby ocean was dissolved in rainwater and seeped into the structure while Columbia was on the launch pad. Launchings had begun in 1981. “In 1983,” Erikson wrote, “corrosion was detected around the attach points” of the panels. The damage was discovered during careful post-flight interior inspections of the wings. Aluminum splints were glued to the corroded areas, a process that was repeated for several years while Erikson was working at the launch site. He recalled that access to this area was so tight that only one person on his team, “a tiny English fellow,” could even crawl into the wing to perform inspections and repair. Erikson did not know what subsequent repair and replacement was performed after he left in 1985.
~~~~~snip~~~~~
Yet as recently as 2001, corrosion was raised during considerations of Columbia’s major modifications performed at the Palmdale, Calif., manufacturing facility and later at the Kennedy Space Center. When asked if deferring vehicle inspections to a new team in Florida would “incur additional risks,” Richard Blomberg, chairman of NASA’s “Aerospace Safety Advisory Panel,” said: “Personally, I don’t think if we slowed down on the corrosion inspections for a while, that there would be any immediate safety concerns.” However, he expressed concerns about longer-term issues....
Well doc, let's pull the charts and examine the record on that one. I brought up the question of the OMDP [Orbiter Maintenance Down Period] at Palmdale on the day the Columbia was lost, in the very first thread here at FR.
Here is our exchange on OMDP: Shuttle Contact LOST-No Tracking Data During RE-Entry!
To: anymouse
The tire pressure data is not readily available to the crew, IIRC - only on...what was it...Spec 60 or something. Don't know if they would get an SM alert - probably would, but I think that Houston would monitor that stuff for them and advise.
It's hard to imagine how a MLG door could open without a mechanical failure of some kind. The overcenter lock is hydrauliclly operated, with pyro backup.
I just heard that this was Columbia's first flight after OMDP. I don't know if that's true, and if so, whether the OMDP was done at Palmdale or KSC.
All I know is that every time an orbiter came back from OMDP at Palmdale, it was totally trashed by those pot-smoking derelicts out there. There were always well over 1,000 IPR's taken on the damage when an orbiter arrived back home. (Yes KSC is their home, not Palmdale.
1208 posted on 02/01/2003 11:24 AM EST by snopercod
To: snopercod
Gads, what's with you guys blaming OMDP in Palmdale.
The ground crews at KSC do more with the vehicle after delivery and there's more than enough blame to go around.
Pointing fingers at Palmdale is totally poor.
1253 posted on 02/01/2003 11:28 AM EST by bonesmccoy (Defeat the terrorists... Vaccinate!)
To: bonesmccoy
Pointing fingers at Palmdale is totally poor.
I didn't realize that you have some connection to Palmdale and/or Rockwell.
This may have absolutely nothing to do with the loss of the Columbia.
BUT, I have personally been in the midbody of the shuttle and seen with my own eyes the "professional" work done by the Palmdale people - the stepped-on boron struts, intercostals, wiring harnesses, and tubing. I have personally viewed the IPR log when the Columbia came back from Palmdale. I have personaly knowledge of the months of additional processing time required to repair all the damage they did out there.
Facts are facts. The Palmdale workers butcher the shuttle every single time they get their hands on it.
1495 posted on 02/01/2003 11:54 AM EST by snopercod
To: snopercod
cheap shot...
california could criticize Florida too.
But given today's events, we will withhold comment.
1764 posted on 02/01/2003 12:57 PM EST by bonesmccoy (Defeat the terrorists... Vaccinate!)
To: bonesmccoy
No cheap shot intended toward you. We can talk about Palmdale some other time, but I did confirm that the OMDP was done there. This is Columbia's first flight after.
On September 24, 1999, Columbia was transported to Palmdale California for its second ODMP. While in California, workers will perform more than 100 modifications on the vehicle. Columbia will be the second orbiter outfitted with the multi-functional electronic display system (MEDS) or "glass cockpit".
(I later corrected myself (#1966). STS-107 was the second flight after OMDP.)
I was wrong that STS-107 was the first flight after OMDP. STS-109 was the first. I corrected myself on the original thread.
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