As expected, NASA today set a new, more realistic target date for launch of the next shuttle mission - between Sept. 12 and Oct. 10, 2004 - and announced a new flight that will be inserted into the launch manifest to complete tasks originally planned for the first mission.

Given post-accident requirements that sharply restrict when a shuttle can actually take off, however - launch and external tank separation in daylight and thermal constraints at the international space station - the shuttle's return to flight easily could slip into 2005 when all is said and done.

Those requirements currently translate into 26 days of launch opportunities between Sept. 16 and Oct. 11, 2004; Nov. 19-21, 2004; and Jan. 17 through 19, 2005. The next available launch window opens in March 2005.

Current estimates show photo documentation of external tank separation in daylight will not be possible until Sept. 16. But NASA managers say those estimates might change and so they added a bit of cushion to the front end of the target launch window.

Bill Readdy, NASA's associate administrator for space flight, stressed the new launch window, like the original March/April target window, remains a target only and that it may change again as planners get a better idea of how much work remains to be done.

Mission STS-114, currently assigned to the shuttle Atlantis, will include a robot arm extension and sensors to look for damage to the ship's heat-shield tiles and leading edge panels; a spacewalk to test tile and leading edge repair techniques; another spacewalk to install a new gyroscope on the space station; and supply and equipment transfers to and from the lab complex.

"We're going to be very much driven by the milestones and by the content we have to accomplish here in terms of the testing of the robotic arm, survey techniques, tile repair, modifications to the external tank, all the testing that's required," Readdy said in an evening teleconference with reporters. "So It comes down to being able to satisfactorily accomplish all of those.

"I can't tell you whether or not we're going to have more content creep in over time, whether we're going to come up on some technical hurdles. I can almost guarantee that this is going to be a long, uphill climb back to return to flight. But I also would tell you that we're getting an awful lot smarter about this and we're going to come back stronger and safer as a result."

To accommodate the tile/leading edge inspections and the repair demonstration spacewalk, NASA decided to split the original STS-114 mission into two separate flights. The new mission, known as STS-121, currently is assigned to the shuttle Discovery. It is targeted for launch Nov. 15. Again, that's a few days in advance of when a daylight tank separation because available.

Making the September launch date for the first post-Columbia mission will not be easy. Long poles include development of the robot arm extension boom and the sensors needed for in-orbit tile and leading edge inspections and development of viable techniques for repairing leading edge damage. A wild card is the impact of work to remove Atlantis' carbon composite nose cap for an extensive corrosion inspection.

But shuttle program manager Bill Parsons said it's too soon to predict how all of that might play out. As for the shuttle's sharply restricted launch windows, "I think we have some opportunities, some small opportunities in November and possibly January and some other places."

"But you know, again, we're still refining those requirements, we're still refining exactly what we need to do to meet the lit launch requirement," he said. "But I think there are some opportunities in November (2004) for us to go launch."

In perhaps the most convincing demonstration yet that NASA truly "gets it," the new chairman of the agency's mission management team today outlined major changes to improve communications among engineers and managers, to ensure dissenting views are heard and to correct the cultural shortcomings blamed in part for the Columbia disaster.

"Any arrogance I may have had went out the window on Feb. 1," said Wayne Hale, a widely respected ascent-entry flight director who brings clear credibility to the mission management team. "In my personal life, before February I thought we had it pretty much knocked. ... I would have told you we understood what we were doing and we had mature processes and good hardware. And I think all of those assumptions have been shattered."

As chairman of the revamped mission management team, Hale will oversee the conduct of all phases of flight, from the pre-launch review needed to clear a shuttle for launch to the in-flight management of its mission.

At a news conference, Hale unveiled an ambitious plan to resolve shortcomings found by the Columbia Accident Investigation Board as well as issues identified by NASA personnel in the wake of the accident. New members will be added to the MMT, outside experts will be brought in to coach the managers on decision making skills and regular mission simulations will be held to test those skills in make-believe emergencies.

Hale is even looking into what shape table to use in the MMT conference room.

"Now you laugh," he said to chuckling reporters, "but when you talk about culture and how people subconsciously deal with hierarchy and where they fit within an organization and whether they feel comfortable in bringing things up, things like the shape of the table matter.

"Being trained as an engineer, I'm wishing I'd taken more sociology classes in college. I'm learning a lot, I think we're all learning a lot in this arena and we're committed to opening lines of communication and making sure people get their dissenting opinions and minority opinions on the table so we can consider them."

Some agency veterans have criticized the new MMT plan, saying the additional voices and opinions will make it more difficult to make a final decision. But Hale disagrees.

"I am convinced that we not only should, but must, come to an understanding of why it's OK to proceed in the face of a minority opinion," he said. "My basic model is consensus. We will bring the person from the organization that's got the concern and we should be able to demonstrate in a technical, analytical, engineering sense why it's safe to proceed or we shouldn't proceed. I don't know any other way to do that.

"I will tell you I get resistance from some of the NASA alumni league who operated at a different time and a different culture who think this is not the right thing to do, who think we'll never fly again if we go down this road too far. So there is that element of folks out there. But I think we need to go down the road as far as we can to make sure that we fly safely. Because just going to fly, there's been a lot of noise in the system about launch schedules and launch dates and we've gotta go do this to make the launch schedule, you know. We have to make sure when we get ready to fly we have done everything we can to make sure it's safe."

The Columbia Accident Investigation Board was sharply critical of MMT operations during Columbia's ill-fated mission. Contrary to NASA's own rules, the MMT, under chairman Linda Ham, did not meet every day and did not seriously debate the results of a hurried analysis that mistakenly concluded Columbia was not seriously damaged by a foam debris strike during launch. Despite an almost complete lack of hard data about the possible threat posed by the strike, the MMT quashed efforts by lower-level engineers to obtain spy satellite imagery that might have revealed the extent of the damage.

Hale today vowed to learn from the mistakes of the past. And he left little doubt he believes the management culture at NASA needs to change.

"I have to say, STS-107, the Columbia flight, has been a significant emotional event in my life and I think in the life of everyone in the agency, certainly in the shuttle part of the agency," he said. "We had many of our assumptions and concerns shattered on Feb. 1.

"Those of us who lived through the events of this past spring have had our lives change in ways that are going to affect our decisions and our thought processes for years to come. We have come over the course of several months of introspection and analysis to a new understanding. In particular, the first thing we have to get out on the table is we were not good enough. We did not do what is necessary to keep the Columbia crew safe. And that is something we have to live with as a legacy that will compel us to do the right thing for future shuttle flights and for future human exploration of space."

While final details remain to be resolved, Hale said the new MMT will include:

• Seats for the directors of engineering at the Johnson Space Center in Houston and the Marshall Space Flight Center in Huntsville, Ala.;
• A seat for the director of propulsion technology at Marshall;
• Seats for the head of safety and mission assurance at NASA headquarters and for the newly formed NASA engineering safety center at the Langley Research Center in Hampton, Va.;
• A single manager (Hale) for pre-launch and in-flight operations;
• A re-emphasized rigor with permanent pre-defined agenda items covering all phases of damage assessment to make sure any possible sign of trouble is known to senior management and discussed as widely as possible;
• A dedicated group of engineers to identify possible anomalies across all disciplines;
• Participation by senior managers, not designated alternates;
• Daily meetings

An internal review of the new MMT plan will be complete by Oct. 2. By the middle of the month, all MMT members will attend a class defining the precise roles and responsibilities of panel members. By the first week in November, the MMT will participate in a so-called "warm-up" simulation, the first in a series of regularly scheduled simulations to test MMT decision-making skills.

By the first week in December, Hale hopes to stage a three-day simulation involving the shuttle and the international space station program. Another major simulation including NASA's international space station partners is planned for January with monthly management sims scheduled after that through return to flight.

Long term, outside safety and management experts will be brought in on a regular basis as part of a continuing education program. Bringing in outsiders has never been NASA's strong suit and many at JSC resented the appearance of sociologist Diane Vaughn, an expert on the decision to launch the shuttle Challenger, at a Columbia Accident Investigation Board Hearing. She now is among the experts being sought by NASA.

"I didn't know who Dr. Vaughn was when she appeared at the CAIB hearing," Hale said. "I came away a little unimpressed with it but I said I ought to go get her book and look at what she's got to say. I sat down and read ("The Challenger Launch Decision") and when I got done with it, I said wow, there is a lot of good stuff here that I never thought about. And there is valuable place for us to learn some things.

"And since then, I think I've added a number of books to my bookshelf that are decision-making related that I'm thinking about a lot more these days. And we're going to have a number of these folks come and talk to us."

NASA must develop the capability to repair damaged heat shield tiles in orbit, as well as cracks or breaches in the reinforced carbon carbon panels making up the shuttle's wing leading edges, before space shuttles return to flight, the Columbia Accident Investigation Board says.

In the board's final report, released earlier today, the CAIB made 29 recommendations, 15 of which are to be implemented before the next shuttle flight. Because of the way the report marked those recommendations, using boldface red type "RTF" tags, one five-paragraph recommendation was misinterpreted by some readers who initially thought RCC repair capability was not a requirement for return to flight.

At a news conference and later in an interview with CBS News, board chairman Harold Gehman left no doubt: NASA must be able to repair damage to both tiles and RCC panels before the next shuttle takes off.

"Recommendation 6.4.1 contains four provisions, all of which are return to flight," he said.

That is a significant requirement. While NASA is expected to have a working tile repair technique in hand within a few months, developing a reliable RCC fix is a much greater challenge because of the nature of the material and the extreme 3,000-degree temperatures it is exposed to during re-entry. Some observers believe that requirement alone will push the next shuttle flight into the summer 2004 timeframe if not later.

"We think that's probably the long pole in the tent," Gehman said in an interview. An innovative technique used by Thiokol to repair carbon composite rocket nozzles shows promise and other techniques are under study as well. But repairing breaches in RCC panels is, at present, a long way from reality.

In any case, here is the recommendation in question:

"For missions to the international space station, develop a practicable capability to inspect and effect emergency repairs to the widest possible range of damage to the Thermal Protection System, including both tile and Reinforced Carbon-Carbon, taking advantage of the additional capabilities available when near to or docked at the International Space Station.

"For non-Station missions, develop a comprehensive autonomous (independent of Station) inspection and repair capability to cover the widest possible range of damage scenarios.

"Accomplish an on-orbit Thermal Protection System inspection, using appropriate assets and capabilities, early in all missions.

"The ultimate objective should be a fully autonomous capability for all missions to address the possibility that an International Space Station mission fails to achieve the correct orbit, fails to dock successfully, or is damaged during or after undocking. [RTF]"

Editor's Note: The Columbia Accident Investigation Board, on page 77 of its final report, provided new insights into how the shuttle broke apart and the fate of the orbiter's crew. For the record, here are those observations.

At the Board's request, NASA formed a Crew Survivability Working Group within two weeks of the accident to better understand the cause of crew death and the breakup of the crew module. This group made the following observations.

Medical and Life Sciences
The Working Group found no irregularities in its extensive review of all applicable medical records and crew health data. The Armed Forces Institute of Pathology and the Federal Bureau of Investigation conducted forensic analyses on the remains of the crew of Columbia after they were recovered. It was determined that the acceleration levels the crew module experienced prior to its catastrophic failure were not lethal. The death of the crew members was due to blunt trauma and hypoxia. The exact time of death sometime after 9:00:19 a.m. Eastern Standard Time cannot be determined because of the lack of direct physical or recorded evidence.

Failure of the Crew Module
The forensic evaluation of all recovered crew module/forward fuselage components did not show any evidence of over-pressurization or explosion. This conclusion is supported by both the lack of forensic evidence and a credible source for either sort of event. The failure of the crew module resulted from the thermal degradation of structural properties, which resulted in a rapid catastrophic sequential structural breakdown rather than an instantaneous "explosive" failure.

Separation of the crew module/forward fuselage assembly from the rest of the Orbiter likely occurred immediately in front of the payload bay (between Xo576 and Xo582 bulkheads). Subsequent breakup of the assembly was a result of ballistic heating and dynamic loading. Evaluations of fractures on both primary and secondary structure elements suggest that structural failures occurred at high temperatures and in some cases at high strain rates. An extensive trajectory reconstruction established the most likely breakup sequence, shown below (see chart on page 77 of the CAIB report).

The load and heat rate calculations are shown for the crew module along its reconstructed trajectory. The band superimposed on the trajectory (starting about 9:00:58 a.m. EST) represents the window where all the evaluated debris originated. It appears that the destruction of the crew module took place over a period of 24 seconds beginning at an altitude of approximately 140,000 feet and ending at 105,000 feet. These figures are consistent with the results of independent thermal re-entry and aerodynamic models. The debris footprint proved consistent with the results of these trajectory analyses and models. Approximately 40 to 50 percent, by weight, of the crew module was recovered.

The Working Group's results significantly add to the knowledge gained from the loss of Challenger in 1986. Such knowledge is critical to efforts to improve crew survivability when designing new vehicles and identifying feasible improvements to the existing Orbiters.

Crew Worn Equipment
Videos of the crew during re-entry that have been made public demonstrate that prescribed procedures for use of equipment such as full-pressure suits, gloves, and helmets were not strictly followed. This is confirmed by the Working Group's conclusions that three crew members were not wearing gloves, and one was not wearing a helmet. However, under these circumstances, this did not affect their chances of survival.

NASA will use the Columbia Accident Investigation Board's final report as a blueprint for correcting the problems that led to the Feb. 1 shuttle disaster and returning the shuttle safely to flight, Administrator Sean O'Keefe said today.

"We have accepted the findings and will comply with the recommendations to the best of our ability," O'Keefe said in a statement. "The board has provided NASA with an important road map as we determine when we will be 'fit to fly' again.

"Due to the comprehensive, timely and open public communication displayed by the Board throughout the investigative process, we already have begun to take action on the earlier issued recommendations, and we intend to comply with the full range of recommendations released today."

Harold Gehman, chairman of the Columbia Accident Investigation Board, told CBS News this afternoon NASA has little choice. In the panel's view, he said, NASA cannot safely operate the space shuttle program without major changes in its management system.

"I think there's a little bit of denial that NASA, at least in the shuttle program, that NASA has modified its organizational structure over the years into one that no longer contains the attributes that they built their reputations on," Gehman said. "There may be some people who deny that, but the board is absolutely convinced, we think there's no room for any doubt whatsoever, the management system they have right now is not capable of safely operating the shuttle over the long term. That's the bottom line."

¾Gehman also said Congress and the White House must share blame for the Columbia disaster with NASA. Asked what he might tell President Bush about NASA and the agency's second in-flight tragedy, Gehman said he would point out that "NASA is a great organization that he and the country can have a lot of pride in. And that they are operating under and unrealistic set of rules and guidelines."

"Exploring space on a fixed cost basis is not realistic," the retired admiral said. "Launching shuttles on a calendar basis instead of an event-driven basis is not realistic. Demanding that you save money and run this thing in an efficient and effective way and that you get graded on schedule and things like that is not realistic. That the whole nation and Congress and the White House has an unrealistic view of how we do space exploration."

In addition, the board's report "clearly specifies that there is responsibility at both ends of Pennsylvania Avenue for this that are shared with NASA," Gehman said. "Now in some cases, NASA over markets what they can do. They promise more than they can deliver and they promise they can deliver it at a price that is less than it's really going to cost. But in some cases, it is demanded of them, in order to get a program approved, that they agree to unrealistic schedules and unrealistic price tags. So there's blame at both ends here."

The CAIB report focuses heavily on decisions made NASA's mission management team, the panel of senior agency leaders that oversaw the day-to-day conduct of Columbia's mission. The MMT, chaired by former flight director Linda Ham, shut down efforts to obtain spy satellite photography of Columbia's damaged wing and failed to challenge a hurried analysis that concluded the shuttle was in no danger of a catastrophic failure.

Gehman told CBS News the space agency's management system is so dysfunctional it hardly mattered who was in charge.

"We believe very, very strongly that you could substitute almost anybody in those positions and operate under the guidelines and rules and precedents that were being used in NASA and they would make the same errors," he said.

"Let me give you a specific case in point. Much has been made of the fact that the MMT didn't meet every day. NASA regulations require that they meet every day. So I had my board go back and see what were the meetings scheduled for the previous two shuttle missions? Guess what? They met every third day.

"So Linda Ham was doing her job according to the standards and precedents that were set by the establishment," he continued. "Even though the rules say you have to meet every day, you don't really have to. So that's an organizational flaw and she was performing her duties in that respect in accordance with the standards and precedents that had been previously established by her predecessors. And her predecessor's bosses had let that go on.

"So we feel very, very strongly that just moving the people around won't fix that problem. Unfortunately, we live in a town here in Washington, DC, in which they frequently demand someone pay. But we on the board were not influenced by that" and the board did not assign personal blame for any real or perceived errors in judgment.

Could a more experienced or proactive program manager or MMT chairman have made a different in Columbia's case?

"We feel there's some part of this, maybe even a lot of these problems, could have been mitigated by a stronger, a more suspicious, nervous kind of a person," Gehman said of the MMT and its chairman. "But our conclusion, our very, very strong conclusion is even if you had really brilliant people, really spectacular people, if you had the very, very best person you could get, that it would be a low probability bet that you could count on them to overcome the flaws in the organization. That is a low probability course of action."

Asked if NASA was "in denial" about serious management flaws and defects, Gehman said "in a lot of cases, they will deny that they have a basic organizational flaw which is dangerous. I think they'll deny that, some of them. Others will applaud it. It kind of depends on where you sit."

The CAIB's criticism of NASA drew an unusual response from Stephen Feldman, president of The Astronauts Memorial Foundation.

"One of the great risks of the Columbia tragedy and the subsequent report and commentary is that outstanding scientists and engineers may feel so criticized and unappreciated that they will leave NASA and the space program for higher paying and often less stressful jobs in the private sector," he said in a statement. "The outstanding safety record that NASA has compiled over the years shouldn't be forgotten because of one terrible accident on February 1, 2003." But O'Keefe's promise to full implement the CAIB recommendations drew praise from the National Space Society, a nonprofit advocacy group founded by German rocket scientist Wernher von Braun.

"The National Space Society urges NASA to embrace the recommendations of the CAIB and work diligently to fundamentally reform its decision-making processes and safety organizations so that we can safely return the Space Shuttle fleet to service," said Executive Director Brian Chase. "However, in order for NASA to fully implement the CAIB recommendations and continue the exploration of space, the agency will need appropriate funding to accomplish those tasks.

"The White House and the U.S. Congress must accept their share of responsibility for the future of our nation's space exploration efforts and provide the necessary leadership.

"Perhaps most importantly, NASA and our nation's leaders need to take this opportunity to foster development of new space transportation systems and renew a long-term commitment to human space exploration."

The Columbia Accident Investigation Board released its long-awaited report today, blaming the Feb. 1 disaster on bureaucratic inertia, slipshod internal communications and ineffective management at the top levels of NASA. The scathing, pessimistic tone of the report left little doubt the Board believes the so-called "NASA culture" is deeply flawed and in need of major modifications to prevent a repeat of the Columbia disaster in the years ahead.

"Based on NASA's history of ignoring external recommendations, or making improvements that atrophy with time, the Board has no confidence that the space shuttle can be safely operated for more than a few years based solely on renewed post-accident vigilance," the report states.

Unless NASA takes strong action to change its management culture to enhance safety margins in shuttle operations, "we have no confidence that other 'corrective actions' will improve the safety of shuttle operations. The changes we recommend will be difficult to accomplish - and they will be internally resisted."

For an agency with such a proud tradition - sending 12 men to the surface of the moon, establishing a permanent presence in low Earth orbit, exploring the solar system with unmanned robots and launching scientific sentinels to probe the depths of space and time - the criticism levied by the accident board likely will seem extreme in its harshness.

But the accident investigation board members and their investigators clearly believe the sharp tone is appropriate, in their view essential to ensuring that wide-ranging corrective actions are actually implemented. The board's investigation found that "management decisions made during Columbia's final flight reflect missed opportunities, blocked or ineffective communications channels, flawed analysis and ineffective leadership."

In the end, the report concludes, NASA managers never really understood the lessons of the 1986 Challenger disaster and "echoes of Challenger" abound in the miscues that led to Columbia's destruction.

"Connecting the parts of NASA's organizational system and drawing the parallels with Challenger demonstrate three things," the board found. "First, despite all the post-Challenger changes at NASA and the agency's notable achievements since, the causes of the institutional failure responsible for Challenger have not been fixed.

"Second, the Board strongly believes that if these persistent, systemic flaws are not resolved, the scene is set for another accident. Therefore, the recommendations for change are not only for fixing the shuttle's technical system, but also for fixing each part of the organizational system that produced Columbia's failure.

"Third, the Board's focus on the context in which decision making occurred does not mean that individuals are not responsible and accountable. To the contrary, individuals always must assume responsibility for their actions. What it does mean is that NASA's problems cannot be solved simply by retirements, resignations, or transferring personnel."

The 13-member Columbia Accident Investigation Board, under the leadership of retired Adm. Harold Gehman, spent seven months investigating the Feb. 1 Columbia disaster, reviewing more than 30,000 documents, conducting more than 200 formal interviews and collecting testimony from expert witnesses. The board also oversaw debris recovery efforts in Texas and Louisiana that involved more than 25,000 searchers. The investigation is expected to cost $19.8 million when all is said and done.

The board's 248-page report was released at 10 a.m. at the National Transportation and Safety Board in Washington. Reporters were allowed to review the report ahead of time, surrendering cell phones and wireless laptop network cards before entering a closed off "reading room" at 6 a.m. Gehman and other members of the panel plan to discuss the report during an 11 a.m. news conference. This status report will be updated as soon as possible thereafter.

In the meantime, key lawmakers vowed to take the board's recommendations to heart.

"The people of NASA have accomplished great things," Dana Rohrabacher, D-Calif., chairman of a key House space committee, told CBS News Monday. "They've put a man on the moon within a very short period of time, the people of NASA have been a source of great pride ... for the people of the United States.

"But for far too long, they've been resting on their laurels and bathing in past glories, nostalgic about the glory days," he continued. "It's time to look to the future and it's time to recapture a tough, hard-working body of people who have new challenges and are not just looking at the past but looking to the future. And that means Congress and the president have got to act on the Gehman report."

It should be noted, however, that NASA cannot develop new manned spacecraft or significantly change the general thrust of the nation's space program without approval and funding from Congress and the White House. The Bush administration has been virtually silent when it comes to the nation's manned space program and Congress has not endorsed any major changes beyond controlling the budget of the international space station.

President Bush has not yet weighed in on the report or its implications for NASA and the international space station project. He said last week he wanted a chance to review the report before commenting.

The report focuses on two broad themes: The direct cause of the disaster - falling external fuel tank foam insulation that blasted a deadly hole in the leading edge of Columbia's left wing 82 seconds after liftoff - and the management system that failed to recognize frequent foam shedding as a potentially lethal defect before Columbia even took off.

The report also focuses on how NASA's mission management team, a panel of senior agency managers responsible for the day-to-day conduct of Columbia's mission, failed to recognize the severity of the foam strike that actually occurred, virtually eliminating any chance to save the shuttle's crew, either by attempting repairs in orbit or launching a rescue mission.

The report makes 29 recommendations, 15 of which must be implemented before shuttle flights resume. Five of those were released earlier, requiring NASA to eliminate foam shedding to the maximum extent possible; to obtain better imagery from the ground and in orbit to identify any problems with the shuttle's thermal protection system; and development of tools and procedures to repair any such damage in space.

The more difficult recommendations address management changes and the establishment of an independent Technical Engineering Authority to verify launch readiness, oversee and coordinate requests for waivers and to "decide what is and is not an anomalous event." The TEA "should have no connection to or responsibility for schedule and program cost." In addition, NASA's Office of Safety and Mission Assurance should have direct authority over all shuttle safety programs and be independently funded.

"It is the Board's opinion that good leadership can direct a culture to adapt to new realities," the panel wrote. "NASA's culture must change, and the Board intends (its) recommendations to be steps toward effecting this change."

Columbia, carrying a crew of seven and scores of scientific experiments, blasted off from the Kennedy Space Center in Florida on Jan. 16. Strapped in on Columbia's upper flight deck were commander Rick Husband, making his second flight; rookie pilot William "Willie" McCool; flight engineer Kalpana Chawla, making her second flight; and rookie astronaut-flight surgeon Laurel Clark. Seated below on the shuttle's middeck were payload commander Michael Anderson, making his second flight; and two more rookies, physician-astronaut David Brown and Ilan Ramon, the first Israeli space flier.

At 81.7 seconds after liftoff from pad 39A, a suitcase-size chunk of foam broke away from the ship's external fuel tank and slammed into the left wing. The shuttle was racing skyward at more than twice the speed of sound at the time - 1,650 mph - and engineers later calculated the foam hit the left wing at some 530 mph.

The foam strike was not seen until the day after launch when engineers began reviewing tracking camera footage as they do after every launching. A film camera in Cocoa Beach that could have photographed the impact on the underside of the left wing was out of focus. A video camera at the same site was properly focused, but it lacked the resolution, or clarity, to show exactly where the foam hit or whether it caused any damage. A third camera at a different site showed the foam disappearing under the left wing and emerging as a cloud of debris after striking the underside. Again, the exact impact point could not be seen.

Stunned engineers immediately began analyzing the available film and video and ultimately determined the foam had struck heat shield tiles on the underside of the wing, perhaps near the left main landing gear door. No one ever seriously considered a direct heat on the reinforced carbon carbon panels making up the wing leading edge because no trace of foam debris was ever seen crossing the top of the wing. As the board ultimately concluded, however, the foam did, in fact, strike the leading edge on the lower side of RCC panel No. 8.

In hindsight, it's difficult to understand why the possibility of a leading edge impact didn't receive more attention. The board concluded that was due at least in part to the influential role of Calvin Schomburg, a senior engineer at the Johnson Space Center with expertise in the shuttle's heat-shield tiles.

"Shuttle program managers regarded Schomburg as an expert on the thermal protection system," the board wrote. "However, the board notes that Schomburg as not an expert on reinforced carbon carbon (RCC), which initial debris analysis indicated the foam may have struck. Because neither Schomburg nor shuttle management rigorously differentiated between tiles and RCC panels, the bounds of Schomburg's expertise were never properly qualified or questioned."

In any case, a team of Boeing engineers at the Johnson Space Center, under direction of NASA's mission management team, ultimately concluded the foam strike did not pose a safety of flight issue. Their analysis, using a computer program called CRATER, predicted areas of localized, possibly severe damage to the underside of the left wing, but no catastrophic breach. The concern, rather, was that any damage likely would require extensive repairs before Columbia could fly again.

While the damage assessment was getting under way, at least three different attempts were made to obtain spy satellite photography of the impact site to resolve the matter one way or the other. But in a series of communications miscues, the efforts ultimately were quashed by the MMT, under the direction of former flight director Linda Ham.

Ham says she was never able to find out who wanted such photographs and, without a formal requirement, had no reason to proceed. As for the debris assessment, Ham and other members of the MMT never challenged the hurried analysis or questioned the conclusion Columbia could safely return to Earth as is.

Many mid-level engineers said later they had serious misgivings about the debris assessment and heavy email traffic indicated fairly widespread concern about potentially serious problems if the foam strike had compromised Columbia's left main landing gear. Yet those concerns never percolated up the Ham, Dittemore or other members of the mission management team.

Ham and Dittemore both have said they were always open for questions or comments from lower-level engineers and that everyone on the team was encouraged, even duty bound, to bring any serious concerns to the attention of senior management.

But the CAIB disagreed.

"Communication did not flow effectively up to or down from program managers," the board wrote. "After the accident, program managers stated privately and publicly that if engineers had a safety concern, they were obligated to communicate their concerns to management. Managers did not seem to understand that as leaders they had a corresponding and perhaps greater obligation to create viable routes for the engineering community to express their views and receive information. This barrier to communications not only blocked the flow of information to managers but it also prevented the downstream flow of information from managers to engineers, leaving Debris Assessment Team members no basis for understanding the reasoning behind Mission Management Team decisions."

As for not hearing any dissent, the board wrote, "managers' claims that they didn't hear the engineers' concerns were due in part to their not asking or listening."

"Management decisions made during Columbia's final flight reflect missed opportunities, blocked or ineffective communications channels, flawed analysis and ineffective leadership," the board wrote. "Perhaps most striking is the fact that management - including Shuttle Program, Mission Management Team, Mission Evaluation Room (personnel) and flight director and mission control - displayed no interest in understanding a problem and its implications.

"Because managers failed to avail themselves of the wide range of expertise and opinion necessary to achieve the best answer to the debris strike question - 'Was this a safety-of-flight concern?' - some space shuttle program managers failed to fulfill the implicit contract to do whatever is possible to ensure the safety of the crew. In fact, their management techniques unknowingly imposed barriers that kept at bay both engineering concerns and dissenting views and ultimately helped create 'blind spots' that prevented them from seeing the danger the foam strike posed."

Shuttle program manager Dittemore and members of the mission management team "had, over the course of the space shuttle program, gradually become inured to external tank foam losses and on a fundamental level did not believe foam striking the vehicle posed a critical threat to the orbiter," the board wrote.

In the end, many NASA managers say privately, it was a moot point. Once the foam breached the leading edge of Columbia's left wing, the crew was doomed. The astronauts had no way to repair the breach - no robot arm and no tile repair equipment - and there was no realistic chance another shuttle could be readied in time for a rescue mission.

Maybe so. But NASA's flawed management system never gave the agency a chance to prove it still had the "right stuff."

It is that institutional system, or "culture," at NASA that must be changed, the board believes, to prevent another accident.

"An organization system failure calls for corrective measures that address all relevant levels of the organization, but the Board's investigation shows that for all its cutting-edge technologies, 'diving-catch' rescues and imaginative plans for the technology and the future of space exploration, NASA has shown very little understanding of the inner workings of its own organization," the report states.

"NASA's bureaucratic structure kept important information from reaching engineers and managers alike. The same NASA whose engineers showed initiative and a solid working knowledge of how to get things done fast had a managerial culture with an allegiance to bureaucracy and cost-efficiency that squelched the engineers' efforts.

"When it came to managers' own actions, however, a different set of rules prevailed. The Board found that Mission Management Team decision-making operated outside the rules even as it held its engineers to a stifling protocol. Management was not able to recognize that in unprecedented conditions, when lives are on the line, flexibility and democratic process should take priority over bureaucratic response."

The addition of a time-consuming tile inspection on the next shuttle flight, a spacewalk to test new tile repair equipment and techniques and lack of a third space station crew member to assist in equipment transfer work is forcing NASA managers to consider major changes to reduce the crew's workload.

While a variety of options is under study, it does not appear likely the STS-114 shuttle crew, commanded by Eileen Collins, will be able to accomplish its original objectives, including transfer of a fresh three-person crew and all associated equipment and supplies to the space station. NASA managers are considering the possibility of off-loading the crew transfer to a later flight, either to an additional shuttle mission or, possibly, to a Russian Soyuz flight later next year, and adding non-station crew members to the STS-114 mission to assist with logistics and equipment transfer work.

In addition, some of the mission's scientific objectives may be deferred as well because of weight limitations resulting from the expected addition of tile repair equipment and a long robot arm extension boom needed for post-launch inspection of the shuttle's thermal protection system.

Crew transfer issues depend in large part on when Atlantis can be ready for flight. A new two-person station crew is scheduled for launch aboard a Soyuz ferry craft in mid October. They will return to Earth next spring aboard Atlantis or, if the shuttle is not ready in time, aboard a Soyuz.

Most insiders, including several sources who discussed the issues last week, believe NASA will be hard pressed to get Atlantis off the ground before next summer. In that case, the October station crew likely would be replaced by two fliers launching aboard a Soyuz next April. Whether Atlantis then would take another crew up later that summer, or whether the April station crew would remain aloft until a fresh Soyuz crew arrives in Oct. 2004 - carrying either two or three station fliers - is part of the current debate about Atlantis' mission.

Any option off-loading crew rotation to the Soyuz, obviously, would require Russian concurrence. The Russians have not yet booked, or sold, a Soyuz seat for the October 2004 mission and that flight could, in theory, carry up a fresh three-person station crew. But that remains to be seen.

In the meantime, NASA managers are assessing a variety of options to alleviate the STS-114 crew timeline shortfall. The additional weight of a robot arm tile inspection camera boom, the tile repair demonstration kit and other items mean Atlantis cannot carry the originally planned complement of scientific equipment, the research gear needed to make the shuttle flight a space station "utilization" mission as originally envisioned.

"There is growing impetus, within both the shuttle and the station programs, to request (NASA) headquarters add a shuttle flight, a logistics flight, that would offload the strain of return-to-flight tasks from 114," said one NASA official familiar with the discussions.

Before Columbia's destruction Feb. 1, NASA was readying Atlantis for launch around March 1 to carry a fresh three-man crew to the space station along with supplies and research equipment stowed in a pressurized module known as an MPLM.

In addition, STS-114 features three spacewalks by astronaut Stephen Robinson and Japanese astronaut Soichi Noguchi. The objectives are to install a new control moment gyroscope, or CMG; to mount an external stowage platform, or ESP, on the outside of the station for use during upcoming solar array reconfigurations; and to mount TV camera gear and other equipment on the station's exterior.

In the wake of the Columbia tragedy, the station's three-man crew was replaced with two fliers, Yuri Malenchenko and Ed Lu. Because of limitations on fresh water, NASA and the Russian space agency will continue to staff the station with two-person crews until shuttle flights resume, leaving the STS-114 crew with a shortage of manpower in orbit to unloaded the pressurized logistics module.

The Columbia Accident Investigation Board, which will release its final report Tuesday, already has released five preliminary recommendations, including one requiring NASA to carry out extensive on-orbit tile inspections and another requiring development of an in-flight tile repair capability.

Since then, engineers have developed a lengthy tile inspection procedure expected to be carried out on the second day of the mission, in which cameras mounted on a long boom will be maneuvered about the orbiter by the shuttle's robot arm to look for signs of damage. The procedure will involve two astronauts and take up to seven hours or more to complete, throwing a wrench of sorts into normal flight-day two equipment check-out activity.

Areas of the shuttle that cannot be seen by the camera boom will be inspected by the station crew during Atlantis' final approach when Collins performs a pitch maneuver to expose the underside of the orbiter to view from the station above. She already is practicing the maneuver in flight simulators at the Johnson Space Center in Houston.

Once docked, the MPLM will have to be unloaded with one less station astronaut than usual. NASA managers are evaluating a variety of options to lighten the load, in some cases literally, by deferring some transfer items to later missions.

Agency officials hope to carry out at least two spacewalks. The CMG replacement and the tile repair demonstration. The ESP installation also is a top priority because it includes equipment that will be needed by an upcoming assembly crew. Whether it can be accommodated during Atlantis' mission is not yet clear.

The tile repair kit will be located at the back of the shuttle's cargo bay and feature a panel of deliberately damaged heat shield tiles. The spacewalkers will attempt to repair the tiles using materials and procedures currently in the development stage.

The work does not yet include any sort of repair demonstration for reinforced carbon carbon panels making up the orbiter's wing leading edges. While promising procedures are under study, it's not yet clear whether any repair techniques can be developed in time for a flight next spring.

NASA planners hope to refine the requirements of STS-114 in the next few weeks.

The co-chairman of a panel charged with assessing how well NASA meets the intent of recommendations from the Columbia Accident Investigation Board said today he's not sure the agency will have time to implement critical management changes before shuttle flights resume next year.

Richard Covey, a senior executive with Boeing who flew as pilot of the first post-Challenger mission, also said he was disappointed the safety-conscious management system implemented in the wake of the 1986 Challenger disaster broke down in Columbia's case.

"I wasn't surprised we had an accident," he told reporters after the panel's first public meeting. "Spaceflight is risky, those of us who have flown in space know there's risk and entry has always been (phase of flight) the crews have known was highly risky. So the fact that an accident happened on entry was not necessarily a surprise.

"Now, shocking? Yeah. Disappointing, particularly what I have learned of the process that maybe allowed the situation to develop where we had the accident. That was disappointing to me. It has similarities to the Challenger accident, but not perfectly."

Asked to be more specific, Covey said "the decision-making process, both pre flight and during flight, probably has some similarities to the decision-making process in the Challenger accident. If you look at the way that the known shedding of foam off the external tank was handled, you can go back and say well, all right, we knew we had some issues with the O-rings (in the flawed boosters used by) Challenger. They may not have been the same specific barriers to good decision making that occurred there, but the decision process was flawed, probably in both of those cases similarly."

Columbia was destroyed during re-entry Feb. 1 by a breach in the leading edge of the ship's left wing. The breach most likely was caused by a piece of foam insulation that fell off the shuttle's external tank during launch and struck the leading edge. The external tank project had a history of foam shedding, as Covey said, but it was not considered a safety-of-flight issue and it was not a constraint to launch. Likewise, NASA engineers knew about booster O-ring joint problems but did not ground the fleet before Challenger's final flight.

The Columbia Accident Investigation Board plans to release its report Aug. 26. To remove any doubt about NASA's willingness to follow those recommendations, NASA chartered an independent panel chaired by Covey and former Apollo astronaut Thomas Stafford to assess the agency's response to the CAIB's recommendations. The Return to Flight Task Group plans to submit its final report one month before the next shuttle flight, whenever that might be. NASA hopes to launch the shuttle Atlantis on mission STS-114 as early as March 11.

"The intent of our charter is to establish an independent assessment of NASA's responses to the Columbia Accident Investigation Board's recommendations," Covey said. "We also are asked to observe other safety and operational issues that may be pertinent relative to return to flight. It is not a broad charter, it is relatively narrow and focused. Our intent it to make sure we live up to the intent and the letter of our charter."

The task group includes numerous former NASA managers, including James Adamson, a former astronaut and aerospace executive who now runs his own consulting firm. He said the key element of the panel's charter is whether or not NASA meets the intent of the CAIB's recommendations.

"Our job, on the surface, may sound simple, but we're going to check and see if they've done that," he said. "It's not a simple yes or no question. I think everybody knows there's more than one way to skin a cat and we're going to try to look, to drill down into NASA's response to make sure they've met the intent of the recommendation."

One of the CAIB's five already released recommendations calls for improved imagery during ascent to make sure unwanted events like foam shedding do not go unnoticed. Adamson said that recommendation "is really intended to make sure that we don't re-enter with a hole in the vehicle without knowing it."

"The real intent of that is that NASA's got to take some action to be sure we don't do that again," he said. "And there are lots of ways to do that, some of them include imagery. But we're going to look at how you do that and what they're doing in response and we're going to make our assessment based on the intent."

The CAIB's final report is expected to be critical of NASA's management system and operational culture. Covey would not speculate on what the recommendations might involve, but he cautioned reporters not to expect too much too soon.

"We have already begun to try to scope the way we will address managerial, organizational type of recommendations when they come out of the CAIB," he said. "Because they may not be expected to be implemented before return to flight, then that puts us in a situation where we have to say well, what can we assess in the time period that we're chartered to do assessments? So our approach may be to look at plans, strategies or approaches that may be in place prior to the first flight and do an assessment. But it would not be a complete assessment because the real implementation may take longer."

Covey said he agreed with CAIB members who have said the shuttle should be viewed as an experimental spacecraft and not an operational vehicle.

"It goes back to my background as a test pilot and my understanding of those issues that really are important to make a vehicle operational," Covey said. "We've never been there with the space shuttle program and won't be through its life. So if indeed proper focus is the result of thinking in terms of it being experimental, I can support that. I like that."

But experimental vehicles, by their nature, face extreme risk and Covey said another failure will always be possible.

"Clearly with a fleet of three (remaining) orbiters and the demands of the space station program on our orbiter fleet ... then a safe return to fight and an ability to sustain safe flight without the loss of an orbiter is extremely important and there's no doubt about that," Covey said. "I think everybody's very sensitive to that.

"At the same time, we have to also recognize that the same demands of having safe flight and maintaining our orbiter fleet in order to support space station says we need to fly again. So there's a balance there. We'll never be absolutely sure we won't lose another orbiter. We can't do that and we should not have that expectation. We should be able, however, to find a way to make sure the things we know and the things we can learn about between now and the next flight and all those other flights" are properly implemented.

NASA will respond to the Columbia Accident Investigation Board's recommendations "almost to the letter," a senior agency official said today. But Frederick Gregory, NASA's deputy administrator, downplayed widely publicized criticism of NASA's management culture, saying "it would be difficult for me to define to you what the 'NASA culture' is."

Gregory, William Readdy, NASA's associate administrator for space flight, and Bryan O'Connor, associate administrator for safety and mission assurance - all former shuttle commanders - met with reporters at the Kennedy Space Center today after meeting with members of an independent board charged with assessing NASA's implementation of the accident board's recommendations.

Gregory was repeatedly asked about what NASA plans to do to correct problems with its management philosophy, the so called "NASA culture" that permeates agency operations. One reporter opined many believe it may prove easier to fix the shuttle's technical shortcomings than it will be to correct any major flaws in the agency's mindset before flights resume next year.

But Gregory chose not to answer the reporter's question about what NASA might be planning to address the culture issue in the weeks and months ahead.

"That's an interesting observation," he replied. "We have the five technical recommendations (already released by the CAIB), the report itself won't come out until the end of the month and perhaps some of those things you mentioned might be mentioned. But at this point, we have not received any comments officially from the accident investigation board, justifying or backing up your statements."

This reporter then asked Gregory to respond to the spirit of the first question in light of the virtual certainty the board will find fault with NASA's management procedures. Again, Gregory declined to provide any specifics.

"What we are looking at are not only are the technical issues, what we would look at is any process that might need to be modified or changed as we transition from an ops activity, an operations activity, into a return-to-flight activity," he said. "I think you will see there will be some changes, process changes, that will occur. But at this point only as we move from the operations of the standard activities that we're doing into this return to flight time."

Yet another reporter came at the question from another angle and Gregory replied that he believed most of the criticism of NASA's operating culture originated with a single CAIB member and that the board's findings would not be known until the panel's report is released Aug. 26.

"It would be difficult for me to define to you what the 'NASA culture' is," Gregory said. "As I sit here, and I have three astronauts here, I suspect if you tried to determine what the culture of the three of us is, you would find there are three different cultures here. So that's why I have said, I have to wait and see what, if anything, is being written (by the CAIB) about culture before I can respond to your question."

Readdy was somewhat more forthcoming.

"The comment that it's a 'culture thing' maybe does apply in some small area," he said. "I see a gentleman there who is wearing and Apollo shirt today. We were over in the Saturn 5 display area earlier today. There is a culture there, too, that after the Apollo 204 fire (in 1967) got us back to the moon and focused on mission. So there are different aspects of a culture.

"The real challenge will be for us to identify those things that are very positive about our culture and reinforce those and whatever the CAIB may say in terms of the negative aspects of the culture, to identify those very specifically and fix them."

How NASA plans to accomplish that before next spring was left unsaid.

NASA's current target date for the first post-Columbia mission is March 11, the opening of a window that extends through April 6. The launch window is based on a requirement to launch the next mission in daylight and to make sure its external fuel tank separates with enough lighting to ensure a good photographic assessment of its condition.

Columbia, of course, was destroyed by a breach in the ship's left wing leading edge that investigators believe was caused by a chunk of foam insulation that fell off the external tank during launch.

Most agency insiders believe the March time frame is overly optimistic and that a launching next summer is a more realistic expectation. Readdy said today the shuttle team needs a date to march toward from the standpoint of processing hardware, but he stressed that the next mission will not be launched until all parties agree it is safe to do so.

"We understand that one, we don't have the Columbia Accident Investigation Board final report in front of us so there will likely be adjustments there," he said. "Two, we also understand that perhaps March may be success oriented. But we need to have something to get the team all marching in step on and it appears the window, I think, from March 11 to April 6, honored all the constraints that we know thus far: Daylight launch, daylight external tank separation so we can do assessments there, the beta angle cutouts (for temperature control at the space station).

"Is March ambitious? Probably. But that's how you arrive at what the other, not-so-long poles are, the other things that may be potentially in the critical path and identify those so you can go off and solve them."

Gregory emphasized NASA's drive to launch would be driven by accomplishing milestones and not by any desire to meet a specific date.

""We're committed to return to flight but we are committed to doing so safely as we can," he said. "The point I want to make here is we are milestone-oriented focused, not schedule focused. If you see schedules that have a scheduled launch on it, it's only so our folks can work toward a launch date. But it does not necessarily represent the actual date that we will return to flight with the shuttle."

Earlier today, Gregory, Readdy and O'Connor met with members of the independent board charged with assessing NASA's implementation of CAIB recommendations. The panel is chaired by Apollo astronaut Thomas Stafford and shuttle veteran Richard Covey.

"Our commitment is to independently assess NASA's response and implementation of the findings and recommendations of the CAIB," Gregory said. "As you probably know, there will be no attempt whatsoever to argue or defend a recommendation from the CAIB. We will respond to each of the findings and recommendations and in fact ... we will go further than that. The Stafford-Covey task group will assess our response to the findings and recommendations and will have an opportunity, if they find some areas that they observe that have not been picked up, to make a recommendation to us."

As for when the next shuttle might get off the ground, "we will not fly until we are ready to, we have responded to the CAIB, we've had an assurance from the task group that we are headed down the right road, that we have not deviated, that we have not missed anything. Obviously, we will remain vigilant to any congressional discussions or inquiries."

Said O'Connor: "We're going to return to safe space flight by setting the bar higher than it was before."

The news conference ended with a question about whether NASA will implement every CAIB recommendation before the resumption of shuttle flights.

"I think we will be responding almost to the letter to the recommendations of the board," Gregory said. "Now again, the board has not published the report yet and I may have to back off a little bit. But what we will do is the right thing, my assumption is that we would follow to the letter the recommendations and that's why we have the Stafford-Covey task team there independently assessing our response to the board. They will tell us if we have gone down the wrong path or not."

In an emotion-charged meeting with reporters, Linda Ham, chairman of NASA's mission management team and a lightning rod for criticism of decisions made - or not made - during the shuttle Columbia's ill-fated voyage, spoke publicly for the first time today, defending NASA's management practices but agreeing major changes are needed.

Contrary to some earlier media reports, Ham said she never received any formal requests to obtain spy satellite imagery of Columbia to determine the severity of the foam strike and the issue was not discussed during any of the mission management team meetings held during Columbia's flight.

She said she accepted the results of a hurried Boeing-led analysis, carried out at the request of NASA, that concluded the foam strike was not a safety-of-flight issue. She insisted any lower-level engineers or managers who might have disagreed were free, even encouraged, to voice those concerns directly to her. But no one stepped forward and Ham had no reason to question the engineering analysis.

"It goes without saying we were all trying to do the right thing," she said. "All along, we were basing our decisions on the best information that we had at the time. Nobody wanted to do any harm to anyone. Obviously, nobody wants to hurt the crew. These people are our friends, they're our neighbors, we run with them, work out in the gym with them, you know my husband is an astronaut. I don't believe anyone is at fault for this."

But Ham, a 21-year NASA veteran, former flight director and one of the highest ranking women in the high-pressure world of human space flight operations, was removed from her post as manager of shuttle integration and chairman of the mission management team earlier this summer. She currently is in a sort of management limbo at the Johnson Space Center, where some insiders believe she is being made a scapegoat for decisions that were unanimously supported by the entire MMT.

"She did the best she could do given the information she had," said one official who asked not to be named. "She talked to people she trusted, she listened to the analysis. She doesn't deserve to be crucified for this. But she will be. She already has been. She made mistakes, but we all did."

Meeting with 10 reporters today, including the writer of this report, Ham endured occasionally pointed questions about her role in Columbia's flight, calmly fielding most with technical savvy and occasional glances at type-written notes. But when asked about criticism directed at her personally, she finally lost her composure.

"We were really doing the best we could," she said. "Our goal is to launch and of course keep the crew safe, that's the number one goal, and also bring the orbiter back safely and accomplish the mission. That's our job, our number one job. I think we all take some personal responsibility for this and I certainly feel accountable for the MMT. So it's been very difficult through this.

"I know the important thing to do right now is get the program back on (its) feet, get back to flight and get back to flight more safely than ever. My husband being an astronaut and having two kids, we've all gone through this together..."

She suddenly stopped, eyes filling with tears, and could not continue. Flight director LeRoy Cain, the man in charge of mission control during Columbia's re-entry Feb. 1, handed her a handkerchief while mission operations representative Phil Engelauf answered another question. The briefing continued. But the emotional torment on Ham's face was unmistakable. Whatever one might believe about her role in the management of Columbia's mission, there can be little doubt the disaster is never far from her mind.

"It's unconscionable to me that people can attribute to the members of the MMT or the flight control team or the rest of the folks during these missions anything other than the best of intentions," said Engelauf, himself a veteran shuttle flight director. "These are people of good conscience doing everything in their power to get the right answers. This is what we do for a living. LeRoy sits at that console and his job, and my job when I'm there, is to keep the crew safe and get them home in one piece. That is everything we do here and when we come to work that's all we're focused on.

"So in the end, yes, we lost the crew and we lost the vehicle and we can't escape that and nobody feels worse about that than every one of us who has their hands on these missions every day," Engelauf said. "But it is not because of lack of good intent or lack of effort on anybody's part. If the system fell down, we'll fix the system. But it's really difficult to me to attribute blame to any individual personalities or people. We can find mistakes in analyses and we can find places where we weren't good enough. But it's not because of malice or ill intent."

One of the enduring questions of the post-launch MMT agenda has been disposition of requests for satellite imagery of Columbia to better characterize the extent of any damage to the ship's left wing. At least two such efforts were initiated, but Ham said today the issue was never brought up to the MMT.

"That's interesting question," she said. "We have read (news) reports that the mission management team had declined a request for outside assistance and if you read through the transcripts, you'll note that the mission management team never addressed a request for outside assistance because it never came up in any of the meetings. It never came up to me personally.

"I did hear about a possible request for imagery via a phone call. When I did hear about that possible request, I began to research who was asking. What I wanted to do was find out who that person was and what exactly they wanted to look at so we could get the proper people from the ops team together with this group of people, sit down and make sure that when we made the request we really knew what we were trying to get out of it.

"So I went to our contractor, United Space Alliance, to see if they were making a request, I went to the space shuttle vehicle engineering office and I also went to the mission evaluation room where all the engineering work is done, thinking if anyone knows they will know if there's a such a request out there. I couldn't find any request so we did not pursue that."

She said she had "absolutely no reluctance to ask for outside assistance."

"We certainly would have done that if we could have gotten the right information together and the right people together and done that," she said. "Several weeks after the accident, I did find out who was asking and these folks that were asking were actually in the MMT and never brought it up. They were in the MER (mission evaluation room) meetings before the MMT and never brought it up. So for some reason, they didn't feel comfortable bringing it up in the MMT. Certainly, you would think they would have done that at those other meetings or in the hall or at any time. But it never, ever came up."

As most readers know by now, Columbia's left wing was struck by a falling piece of foam insulation that broke away from the ship's external fuel tank 81 seconds after blastoff Jan. 16. Two flights earlier, another large piece of foam had broken away from the same area of the tank and struck one of the shuttle Atlantis' solid-fuel boosters.

The Columbia debris strike was seen during analysis of launch film the day after liftoff. But the actual site of the impact was not visible and the extent of any resulting damage was unknown. A team of NASA-led contractor engineers began studying possible damage scenarios using a computer program designed to predict damage to the shuttle's heat-shield tiles. Ham said today she was content to give the team time to work before making any hasty decisions.

In the end, the engineers concluded the foam strike might lead to severe localized heat damage during re-entry but it did not pose a catastrophic "safety of flight" threat.

"We were trying to give the technical community sufficient time to do an in-depth analysis," Ham said. "They did do their analysis, they did use the Crater (program) and the other tools they had available to them, I do trust that the Mission Evaluation Room, with their mission experts, would bring forward the results of that and they did come forward on that Friday, the 24th, and said they did not believe there was a safety of flight issue and that there would be no burn through and that at most we would have a potential turn around issue, some work on the orbiter that we'd have to do post flight. I did trust that their analysis and the work they had done was correct."

No one in the MMT objected to the report. But after Columbia's catastrophic re-entry, some engineers let it be known then had deep concerns about the analysis. Ham said she never heard any such concerns. Engelauf and Cain agreed.

"We foster a culture here that very much encourages folks to talk, to communicate, the lines of communications are always open," Cain said. "That's the culture we very much encourage and foster around here. And the reason we do that, as you heard Linda mention earlier ... is because we have the safety of the crew the success of the missions at the forefront of our mind every single day we come to work.

"So in order for us to do our jobs effectively, it is crucial that we have open and clear lines of communications. It is absolutely critical and it is, frankly, expected of every single person in every organization, from the engineer all the way up to the management of the programs. Certainly for human spaceflight endeavors, that's the culture we foster. And I believe it's alive and healthy today."

Ham said lower-level engineers and managers have formal and informal avenues to approach senior management with technical concerns.

"For some reason, we didn't get it either way, which I think is also of interest," she said. "You know, whatever happened somewhere, we probably need to figure that out and see if there is a way we can improve that. But I'd also agree we have wide-open communications, our doors are always open and we're more than willing to hear what people have to say. That's the only way we can operate, that's the only way we're going to hear about these kinds of things and the only way we can continue to fly safely. So we really do need these people to feel comfortable and come forward with their issues."

Said Engelauf: "In the final analysis, every night when I go to bed, (I know) we lost STS-107, we lost the crew, we lost the vehicle. Clearly, that is not the way it is supposed to happen and that is not what we do here. So no matter how you do the arithmetic, we're getting a wrong answer and we have to fix that. We all know that. We're going to have to wait until we get some recommendations from people who look at this from a different perspective. It's very difficult to pinpoint the details. It may be something that just isn't obvious to us. I certainly don't want to leap to the easy answers and fix something that isn't' causing the problem."

Engelauf also addressed another issue that keeps popping up in the disaster investigation: The agency's long history of foam shedding and how senior managers slowly grew to accept what sociologist Diane Vaughan calls the "normalization of deviance."

"We've had incidences of foam coming off the tank throughout the history of the program and the same management processes that I think got us comfortable that that was not really a safety of flight issue have been allowed to continue, rightly or wrongly," Engelauf said. "I don't think you can point to individuals today and say that person got comfortable with it, because we've sort of inherited this from the time when Linda and I were back as front room flight controllers and there was a completely different set of people managing the program.

"But I think the intent is that our processes try to cover these sorts of things, we try to put all the checks and balances in place and we try to do all the analyses and in this particular case, I don't think the problem was that we didn't do the analysis or didn't take notice of the foam. I think we got the wrong answer on the analyses.

Cain said "at least part of the answer has to be that fundamentally, we are dealing with an incredibly complex system. It's the most complicated machine that humans have ever built. And over time, we are going to make some human errors. And that's got to be at least part of the answer. We do everything in our power, every single day in this business, to manage the systems to minimize that. And over time, with this complex of a system and the risky environment of space, that has to be at least part of the answer."

Finally, Ham, Engelauf and Cain agreed that NASA would have done everything possible to mount a rescue mission if the team had realized Columbia faced a catastrophic defect. While it is doubtful any such scenario would have succeeded, all three said NASA certainly would have made the attempt.

"Had we known that there was a catastrophic situation on orbit, we certainly would have done everything we could have, including is there anything we can do for the tile repair, we certainly would have pursued rescue. There's no doubt," Ham said.

Added Cain: "If we had known that we had a problem while we were on orbit, I certainly agree, we would have left literally no stone unturned. As to whether it would have made a difference, I think it's an impossible question to answer."

Editor's Note...
The mission management team transcripts posted by NASA today included little or no punctuation. Punctuation, based on context and content, has been added to the excerpts below to make the passages more readable.

Transcripts of meetings by senior NASA managers during the shuttle Columbia's ill-fated flight show mission management team chairman Linda Ham and other top officials, despite a dearth of technical data, simply did not believe falling insulation from the ship's external fuel tank could cause a catastrophic breach in the ship's left wing.

The transcripts, posted on a NASA web site today, include extensive discussions of relatively minor temperature control problems with Columbia's Spacehab research module and debate about the shuttle's slightly over-limit landing weight. But there is surprisingly little discussion about the foam strike investigators now believed doomed the ship 81 seconds after blastoff Jan. 16.

Instead, the management team unanimously accepted, with only a smattering of questions from Ham, the results of a hurried analysis that concluded the worst threat Columbia faced was possibly severe, but localized, tile damage that might require repairs between flights.

Ham has declined all interview requests since the shuttle tragedy and has not participated in any news briefings to this point. With the benefit of 20-20 hindsight, she has been criticized by some observers for not recognizing the severity of the foam strike and its potential for causing catastrophic damage. As chairman of the MMT, she also has been blamed for quashing efforts to obtain spy satellite photography of the shuttle to better characterize any potential damage.

But the widely reported, unsuccessful efforts to obtain spy satellite imagery were not discussed at the MMT meetings, the transcripts show, and in any case, sources say, those efforts primarily were derailed by lower level managers before reaching the MMT chairman.

Ham remains in the shuttle program office at the Johnson Space Center, but earlier this summer she was removed from her post as program integration manager and replaced by flight director John Shannon. Wayne Hale, a former flight director who now serves as deputy program manager under William Parsons, is expected to assume Ham's role in future MMT meetings.

As for Ham's role chairing the MMT meetings during Columbia's flight, the transcripts show no particularly unusual comments on her part or any obviously questionable decisions. But surprisingly, the foam strike was never a top-of-the-agenda item and it was discussed only sparingly, in summary format, and with no debate even though the strike was the most significant such impact ever observed.

When it was discussed, the team focused almost totally on possible damage to the heat shield tiles on the underside of Columbia's left wing and all but dismissed the possibility the foam strike could have damaged the reinforced carbon carbon - RCC - panels making up the wing leading edge. This was a particularly striking turn of events considering there was little or test data on how the carbon composite leading edge panels might respond to a strike by a large piece of foam and there was uncertainty about exactly where the foam had hit the wing.

During the third MMT meeting of Columbia's mission, held on Jan. 24, Don McCormack, representing NASA's mission evaluation room support team, told Ham engineers had started an assessment of potential tile damage using a program called "Crater."

While the analysis was not yet complete, McCormack said, "obviously thereÕs potential for significant tile damage here, but they do not indicate, the thermal analysis does not indicate that there is a potential for a burn through. There could be localized heating damage. Obviously, there is a lot of uncertainty in all this in terms of the size of the debris and where it hit and angle of incidence and, uh, its difficult..."

"No burn-through means no catastrophic damage and localized heating damage would mean a tile replacement?" Ham asked.

"It would mean possible impact to turnaround repairs and that sort of thing, but we do not see any kind of safety of flight issue here, yet, in anything that weÕve looked at."

"No safety of flight and no issue for this mission, nothing that weÕre going to do different, there may be a turn around (issue)?"

"Right, right, It could potentially hit the RCC and we donÕt indicate, other than possible coating damage or something, we donÕt see any issue if it hit the RCC. Although ... we could have some significant tile damage, we donÕt see a safety of flight issue."

Ham asked him to elaborate - "what do you mean by that?" - and McCormack said the foam could have scooped out a fairly large area of tile on the underside of the left wing. Even so, Calvin Schomburg, a tile expert, reassured the MMT that no burn throughs were expected and the foam strike did not represent a safety of flight issue.

In the process of discussing potential tile damage, Ham and her colleagues never revisited the RCC issue even though there was little or no data presented about how the carbon composite panels would respond to a significant impact. And the impact seen during Columbia's launching was the most significant on record.

After complaints that MMT participants listening in by phone could not hear, Ham repeated that Schomburg, who had no expertise in RCC systems, "does not believe that there is any burn throughs, so no safety of flight kind of issue. It's more of a turn around issue similar to what we have had on other flights. ThatÕs it? All right, any questions on that?"

There were no questions. And with that, any lingering concern about the health of the RCC panels was dismissed.

The foam in question broke away from the left-side "bipod ramp" area of the external tank where two large struts attach the nose of the shuttle to the top of the tank. To keep ice from forming on the struts and falling onto the shuttle, foam insulation is sprayed on the tank and then sculpted by hand to form two aerodynamic ramps, or slopes, at the base of each strut making up the bipod.

Eight-one seconds after Columbia blasted off from the Kennedy Space Center, a 1.67-pound chunk of foam from the left bipod ramp area broke free and slammed into the ship's wing at more than 500 mph. Engineers now believe it hit the leading edge on the lower side of RCC panel No. 8, punching a hole in the panel or causing enough damage to result in breach of some sort.

Recent tests at the Southwest Research Institute in San Antonio, Texas, clearly demonstrated such a breach was possible.

While the details are not known with certainty, engineers believe Columbia re-entered Earth's atmosphere Feb. 1 with a hole of some sort in the left wing leading edge. Sixteen minutes after falling into the discernible atmosphere, Columbia's flight computers lost control of the orbiter and the shuttle broke apart. Commander Rick Husband and his six crewmates were killed.

The foam strike was not discovered until engineers examined launch film the day after liftoff. The first of five mission management team meetings carried out during Columbia's flight was held earlier that day but there was no mention of the foam strike. Three days later, however, during the next MMT meeting on Jan. 21, McCormack briefed Ham and the rest of the team on the issue.

"As everyone knows, we took the hit ... somewhere on the left wing leading edge and the photo/TV guys are completed, I think, pretty much their work, although I know IÕm sure theyÕre still reviewing their stuff and they have given us, you know, approximate size for the debris and approximate area for where it came from and approximately where it hit. So we are, you know, talking about doing some sort of "parametric" type analyses and also, weÕre talking about looking at what you can do in event we really have some damage there. But..."

Ham interrupted, recalling shuttle mission STS-112 the previous October when a large piece of bipod foam fell off and struck one of the shuttle Atlantis' booster rockets. She said engineers should gather data collected in the wake of that launching, and after an earlier mission in which foam had caused damage, "and make sure that, you know, I hope we had good flight rationale then."

"Yeah, weÕll look at that," McCormack said. "You mention 87, you know we saw some fairly significant damage area between RCC panels 8 and 9 and main landing gear door down at the bottom on STS-87. We did some analyses prior to the STS-89 so, uh..."

He was not referring to actual RCC damage, rather to tile damage between the landing gear door and the leading edge just behind panels 8 and 9.

In any case, Ham interrupted again, saying "And really, I donÕt think there is much we can do, so you know itÕs not really a factor during the flight because there isnÕt much we can do about it. But what IÕm really interested in is making sure our flight rationale two flights ago was good. Maybe this is foam from a different area, IÕm not sure..."

Ham was saying, in effect, there was nothing the crew could do about tile damage in orbit. But she wanted engineers to go back and re-visit the rationale for continuing shuttle flights with a known foam shedding problem to make sure the reasoning was valid.

Toward the end of the Jan. 21 meeting, Lambert Austin, representing the shuttle integration team, made one slightly alarming observation, saying the strike that occurred later in the ascent, when the shuttle was moving faster, than what had occurred during the STS-112 launching.

"And higher machs (velocity) is going to be worse," Ham observed.

"Yes, but that, you know the debris impact locations will be different so thatÕs one of the reasons we have ... basically, like you said, give a little bit of parametric set of data to the orbiter (project) so they can decide what the worse-case scenario might be."

"OK," Ham replied.

At the next MMT meeting, on Jan. 24, McCormack reported that engineers believed there was no safety of flight issue based on the initial Crater results. Phil Engelauf, representing the mission operations directorate, told Ham flight directors had informed the crew about the foam strike and sent up a 16-second video clip "just so they are armed if they get any questions in the press conferences or that sort of thing. We made it very clear to them, no concerns."

Then, during the meeting after that - on Jan. 27 - McCormack provided an update, saying engineers still believed there was no safety of flight issue even if the foam had hit a sensitive area around the left main landing gear door.

"We looked at an area about the size of 30 inches by 7 inches, and, of course, you know, sloped, cratered out area, and our results there were similar to what we got elsewhere and that is, although local degradation of the door structure is likely if we were to have sustained a hit there, there is no predicted burn-through and no safety of flight issue."

"A turn-around issue?" Ham asked.

"Yeah, possibly."

"If it were hit there..."

"If it were hit there, itÕs a critical area there on the door, but also the Integration guys had indicated that they thought it was a low probability location but it was still one that we went off and looked at," McCormack said.

"OK," Ham replied.

"So, that completes the thermal analysis from the debris hit and with that, thatÕs all IÕve got."

The foam strike was mentioned a final time during the final MMT meeting on Jan. 30, two days before Columbia's re-entry. Ham wanted to make sure any film shot by Columbia's astronauts showing the external tank and, possibly, the area where the foam broke free, would be quickly extracted from the shuttle and returned to Houston for analysis. The foam issue would have to be addressed before the shuttle Atlantis could be cleared for launch on the next shuttle mission in March.

The astronauts aboard the shuttle Columbia, strapped into a reinforced module built to withstand extreme forces, likely survived a minute or more beyond the commander's final transmission, sources say. Engineers believe the crew died when the module, buffeted by increasingly extreme aerodynamic forces, finally broke open as it plunged steeply into the thickening atmosphere above Texas.

NASA managers and engineers have been reluctant to discuss the presumed fate of Columbia's crew out of deference to family members and because of the inherently morbid nature of such speculation. Speaking privately, NASA sources told CBS News last week the crew almost certainly survived the shuttle's initial breakup, but they spoke on background only and asked that details not be repeated. The New York Times, quoting sources with the Columbia Accident Investigation Board, reported a virtually identical scenario late Tuesday, putting the issue in the public spotlight.

Columbia was destroyed during re-entry Feb. 1 after superheated air burned its way into the ship's left wing through a deadly breach in the wing's carbon composite leading edge panels. The first sign of anything amiss was recorded on board the shuttle at 8:48:39 a.m., just four-and-a-half minutes after Columbia fell into the discernible atmosphere 400,000 feet above the Pacific Ocean northwest of Hawaii.

For the next 10 minutes, the shuttle's flight computers held the shuttle on course despite ever-worsening damage to the left wing. But finally, as the hot air burned its way into the left main landing gear wheel well, Columbia's computers displayed a tire pressure fault message on a cockpit display. The message was generated at 8:58:40 a.m. Commander Rick Husband called mission control at the Johnson Space Center in Houston seconds later, beginning "And, uh, Hou(ston)..." But his transmission was cut off.

A half minute or so later, astronaut Charles Hobaugh in mission control replied, "And Columbia, Houston, we see your tire pressure messages and we did not copy your last."

Moments later, Husband replied, "Roger, uh, buh..." and again, was cut off. He might have been saying "both" or "before," possibly referring to the tire pressure fault messages. He sounded calm, but the signal was cut off, engineers believe, by the orbiter's orientation: Radio transmissions from antennas atop the crew module were blocked by Columbia's tail fin.

In any case, nothing more was heard from the crew. At 8:59:32 a.m., all data from the shuttle suddenly stopped flowing to mission control. An on-board data recorder, however, continued operating, allowing engineers to reconstruct the shuttle's final moments after the recorder later was recovered.

A final two-second burst of downlinked telemetry was captured on the ground beginning at 9:00:02.66 a.m. At that point, the shuttle's left wing, or a large portion of it, was gone and Columbia's left orbital maneuvering system rocket pod showed signs of severe damage. The orbiter was in an "uncommanded orientation," rapidly yawing to one side. The shuttle's aft engine compartment, fuselage, right wing and crew cabin, however, were essentially intact. All three electricity producing fuel cells were operating and the life support system appeared to be functioning normally, although the ship's cooling system had shut down.

By that point, the astronauts clearly knew Columbia had suffered a catastrophic failure. But there was nothing they could do. A bit of telemetry toward the end suggested one of the pilots might have briefly moved his joystick hand controller beyond its neutral, or "detent," position. But Harold Gehman, chairman of the Columbia Accident Investigation Board, implied last week that likely was an inadvertent "stick bump" and not an attempt to take over control.

The final bit of downlinked telemetry from the shuttle timed out at 9:00:04.826 a.m. For the next 13 seconds, the shuttle's data recorder continued to function, drawing power from the fuel cells mounted beneath the floor of the payload bay. Finally, around 9:00:18 a.m., the recorder suddenly stopped as the fuselage broke apart and the electrical system failed.

The reinforced crew module, sources told CBS News, likely survived the breakup intact, much like Challenger's did when that shuttle broke up during launch in 1986. Up until the moment Columbia's fuselage failed, data from the recovered recorder indicates the crew module did not experience any fatal accelerations. How long the astronauts might have survived as the crew module plunged earthward will never be known. Sadly, they almost certainly had time to understand their fate.

The Columbia Accident Investigation Board today released a definitive scenario detailing the doomed shuttle's countdown, launch and re-entry, a scenario that merges all available telemetry from the orbiter, recorded data, debris analysis and complex computer simulations. The result is the most complete picture yet showing how a foam strike during launch punched a catastrophic hole in the shuttle's left wing that led to the ship's destruction during re-entry Feb. 1.

Board member Scott Hubbard also presented additional data from a dramatic test last Monday that lends additional credence to the updated scenario. In the test, a chunk of external tank foam insulation was fired at a wing leading edge mockup at the Southwest Research Institute in San Antonio under conditions that simulated the actual foam strike known to have occurred 82 seconds after Columbia's launching Jan. 1.

Along with blasting a 16-by-17-inch-wide hole in reinforced carbon carbon panel No. 8 - the same carbon composite panel believed to have been struck during Columbia's liftoff - the impact also broke an internal lug fitting and caused severe cracks in the surrounding material.

Hubbard said two large fragments of RCC material were blown into the breach by the impact. Dramatic high-speed camera footage shot inside a cavity behind the leading edge panels showed the fragments blowing inward with extraordinary violence. Hubbard said a similar fragment, having a surface area of 90 square inches or more, is perhaps the best explanation for a mysterious object detected by ground radar systems the day after launch that was seen slowly separating from the shuttle. The idea is a large fragment could have lodged in the breach during launch and then floated free after a day of maneuvering in orbit.

On top of that, cracking similar to that seen around the breach in the wing mockup likely led to debris shedding during re-entry. Amateur shuttle watchers on the ground filmed what appeared to be flaming debris falling away from the descending orbiter well west of Texas. Finally, the broken lug fitting observed after Monday's test would have provided a way for a so-called T-seal between RCC panels 8 and 9 to rock open and closed during entry, providing just the sort of intermittent heating needed to explain heat damage that, until now, had defied explanation.

"The board felt this testing was very, very important because it will help us, it will determine how strong a word we use to equate the foam strike, which we know happened, to the creation of some kind of damage that was pre-existing prior to the entry," CAIB chairman Harold Gehman said Friday. "This allows us now to use a word, which we haven't agreed to yet, but use a word that expresses high confidence, a very high degree of confidence that we have indeed found the cause here."

Board member James Hallock said the actual breach probably was in the six- to 10-inch-wide range. A larger hole would have let so much heat into the wing during the initial stages of re-entry that Columbia probably would not have survived all the way to Texas.

But figuring out the mechanical failure mode is only part of the CAIB's goal. The board's final report, now expected around Aug. 26, will focus just as strongly on management issues and shortcomings.

"We started off with kind of a hierarchy of factors," said Gehman. "We had the direct, mechanical thing and then below that, we had contributing factors. We've now decided that these things are equal. That's why we're being so cautious and so careful about the management sections and the safety sections and all those kinds of things. Because the way the report is going to characterize these things is we have what we're now calling the physical, or mechanical failure, and then we have the systemic failures and we're now giving them equal weight. It would be premature to go much further than that because we're writing that section."

But Gehman made it quite clear the board views the space shuttle as an experimental spacecraft as opposed to an operational vehicle. He has said that before, but today he gave a bit more background on how the board views the shuttle system.

"In the case of an operational vehicle, like a commercial airliner or something like that, the events that you use the vehicle for - takeoff and landing and transporting people and then also the turnaround in between flights - if it's an operational vehicle, you expect each one of these events will be nearly identical and repeatable," he said. "And therefore, it's easy and it's logical and it's prudent to contract that out because you essentially want repeatability, you want the thing to happen exactly the same way each time and you expect the same results each time.

"If, on the other hand, it's a developmental vehicle, your expectation is it will not be the same every time. You are always on the lookout for little, tiny little differences, your suspicious of little tiny little differences and also you demand extraordinarily accurate and intrusive instrumentation so you can detect little variances in how the thing operates.

"And you also don't have an expectation that when the thing lands that you can turn it around and get it back in the air again quickly," he said. "There is no expectation that you can do that and there's no expectation you can do that economically. To me, those are the big differences. I cannot emphasize too strongly how much the board is impressed with how deeply and how broadly the differences translate themselves into practical applications. ... We consider it to be truly significant."

Asked if NASA had to be able to repair RCC holes 16 inches across in order to resume shuttle flights, Gehman said "they have to be able to repair holes in RCC caused by debris."

"If they can't stop the debris, they've got to be able to fix the hole," he said. "If they can stop the debris to where it's tiny little pieces of debris and it causes tiny little holes, then they can have a tiny little hole fixer."

Columbia, of course, was struck with the largest piece of foam debris on record, a 1.8-pound suitcase-sized chunk that broke away from the so-called bi-pod ramp area where one of two large struts attaches the nose of the shuttle to the external fuel tank. NASA engineers now plan to launch future shuttles without any such foam insulation, using heaters instead to prevent ice buildups before launch.

"No shuttle is going to fly with a bi-pod ramp again, so you're not going to see this happen again, I don't think," Gehman said. "And I mentioned this before in press conferences and it's in our interim recommendations, that we view this as a system. NASA has to cut down on the amount of debris that comes off, they have to toughen the orbiter, they have to be able to inspect and repair the orbiter and then they've also got to give the crew a better chance to survive. All four of these contribute to safer operations and no any one of them, in my view, is a fix."

Whether NASA can address all such factors before next summer is an open question. Most insiders still believe NASA will have a hard time launching the next mission before the middle of next summer at the earliest, but agency leaders continue to hold out hope for a return to flight next spring.

While Gehman said he still believes NASA can make the necessary fixes in time for a flight six to nine months from now, he also said "the board is convinced that coming and going into orbit remains an enormously dangerous task."

"And even if you had the world's best engineers and world's best managers working on this thing, there's still a high degree of risk in what we're doing here. It's still not flying in a commercial airliner, it's not like taking a drive in your car. It's dangerous. It's very dangerous, and it will remain that way.

"So under that rubric, you could say that even if we had the best managers and best engineers in the world, you're in a business where something can still cause you to have a tragedy like this.

"On the other hand, when looking into this particular accident, we think we have found some issues, some practices, some managerial, budgetary kinds of things, which we believe could be done better even if we had not had this accident. I mean, if they had (formed) this panel to look at NASA for five months, seven days a week like we have, I suspect we would come up with probably the same set of recommendations even if the Columbia had not been lost."

While the mechanical cause of the accident seems clear, the CAIB report will not be 100 percent conclusive. Engineers simply cannot rule out a space debris impact of some sort or even impact by debris from a possibly faulty "bolt catcher" in the booster-external tank separation system.

As for management issues, Gehman declined to comment other than to toss out a few hints.

"We are not consciously saving up things for the report," he said. "But there are some parts of the report that really we have not said a whole lot about. ... The board is still wrestling with some of the words and some of the findings. That part is not very mature yet. ... And also, you haven't seen all of this written down on one piece of paper yet.

"We've talked about a thing here and a thing there, we've talked about inspections this and quality assurance that and testing of this and these things. But when you see it all written down, the tone may be something we haven't come across yet. ... There may be some news value in the tone of the report."

That might rank as one of the greater understatements of the investigation, which Gehman said likely will cost $15 million to $20 million when all is said and done.

"If you agree with me that we have not perfected, we have not learned everything we need to know yet about routinely going into space and coming back out of space, then even if you have a situation where you have a tragedy like this, your obligation to learn as much as you possibly can," Gehman said.

"And the fact that we've allowed cameras and range instrumentation and on-board instrumentation and all kinds of things like that to kind of gracefully atrophy over the years leads me to bring this issue up that there are some signs that it's been considered a routine operation or an operational vehicle rather than a test vehicle."

In a dramatic test that drew startled gasps from onlookers, engineers fired a chunk of foam insulation at a mockup of a shuttle wing leading edge today, blowing a gaping 16-inch-wide hole in the carbon composite structure and putting to rest any lingering doubts a launch-day foam strike was responsible for the Columbia disaster.

"We believe we have found the smoking gun, we believe we've established that the foam block that fell off the external tank (during Columbia's launching) was, in fact, the most probable cause, the direct cause of the Columbia accident," said Scott Hubbard, a member of the Columbia Accident Investigation Board. "I've now got a direct connection between foam shedding creating a hole that's the same order of magnitude as what must have been there when Columbia came home on Feb. 1."

Eighty one seconds after liftoff Jan. 16, a 1.67-pound chunk of foam insulation broke away from the shuttle's external fuel tank and slammed into the left wing at more than 500 mph. Enhanced video from the one camera that viewed the impact point indicated the foam struck the leading edge at or very near the lower side of reinforced carbon carbon panel No. 8, one of 22 such panels making up the leading edge of the left wing.

But the grainy video, unable to resolve anything smaller than two square feet, provided no direct evidence of actual damage. While most engineers believed the foam strike must have contributed to the breach that ultimately caused Columbia's destruction, they had no proof.

In the wake of the mishap, the Columbia Accident Investigation Board, working with NASA, decided to conduct a complex series of tests to find out whether impacts by low-density foam could, in fact, cause the kind of damage needed to bring down the shuttle. A full-scale mockup of the shuttle's wing leading edge system was built and shipped to the Southwest Research Institute in San Antonio, Texas, where a nitrogen gas cannon was available to simulate the launch-day foam strike.

Initial tests showed foam impacts could cause damage, but the results were not clear cut. Then again, the initial tests involved impacts at RCC panel No. 6, located closer to the shuttle's fuselage. RCC 6 is not as large as panel 8 and does not feature the same complex curvature. For today's test, a foam bullet was fired at the lower side of RCC panel 8, one taken from another shuttle and one with 27 previous flights to its credit.

This time around, the cannon barrel was "clocked," or tilted, 30 degrees to more accurately duplicate the predicted impact energy. The aim point was adjusted to strike the underside of RCC 8 closer to a seal between panels 8 and 9. And this time around, the results were dramatically different.

"There is a huge hole in panel 8!" one observer marveled moments after the test. "It's gone, I mean the foam didn't make it to the back (containment) curtain. You talk about an impact! Unbelievable. If you wanted a smoking gun, you've got it."

Speaking to reporters after the test, Hubbard said high-speed video showed an initial rip that "tears all the way across the panel and produces the hole. The hole is very ragged, about 16 inches by 16 inches, or about 256 square inches. There are a number of pieces that are inside the wing leading edge as well as pieces that fell outside."

One of the enduring mysteries of the investigation has been radar data indicating a piece of debris of some sort separated from Columbia the day after launch. In today's test, the foam essentially blew into the leading edge, pushing large pieces of RCC inside. Based on the size of the breach and the size of the fragments inside the leading edge cavity directly behind the RCC panels, Hubbard said the "flight day 2 object" likely was a large section of RCC 8 that worked its way free in the weightlessness of orbit.

The object seen by radar drifting away from Columbia could "very likely be part of the carbon panel itself," he said.

The foam was fired at the wing mockup at roughly 775 feet per second, or about 530 mph, at an impact angle of 22 degrees. That's higher than the impact angle during Columbia's launch. But by adjusting the impact angle, engineers were able to account for rotational energy imparted by the tumbling foam. Hubbard said the impact imparted about a ton of force to the RCC panel. All of the test parameters, taken together, represented an "average" set of conditions. The actual impact could have been somewhat worse or somewhat less violent. But the hole that was blown in RCC 8 leaves little doubt the foam strike caused the breach responsible for Columbia's destruction.

"I was surprised, I was very surprised," Hubbard said. "As a physicist conducting a test, I feel gratified that after months of work we were able to demonstrate this connection between the foam and the damage. But I know it was a source of tragedy, so that makes me feel very sad. This whole six months, we've constantly been reminded by pictures of the seven lost astronauts what this all means."

The CAIB already has released a preliminary recommendation calling for NASA to obtain spy-satellite imagery of shuttles in flight to look for possible signs of damage. The board also has recommended NASA develop techniques for repairing thermal protection system damage in orbit. Hubbard said today's test shows more data also is needed to understand how carbon composite materials age and react to impacts.

"We need to have better imagery, the shuttle program should have the capability for on-orbit inspection and repair," he said. "We need to realize this is a vehicle that needs to be looked at very carefully each flight. Aircraft, even experimental aircraft, often go through thousands of flights before they're determined to be operational. This vehicle has only 113 flights."

He said engineers are "working to try to determine whether you can do on-orbit repairs of the reinforced carbon. It is the highest temperature area of the orbiter, so finding materials that will patch that are very difficult. I don't know, personally, any way you can patch a hole this big. But that doesn't mean some expert (can't figure something out).

"The RCC has proven to be a very tough material. I think the first step is understanding RCC panels much better and understanding what kind of damage thresholds there are. Where is the dividing point? That database doesn't exist and I think that's one of the first things the shuttle program is going to have to work on."

The commander of the shuttle Columbia was informed about the foam strike most believe led to the ship's destruction in a casual email from mission control a full week after liftoff. Even though NASA's internal analysis of the foam incident was not yet complete, the email dismissed any concern about the strike as "not even worth mentioning" and said the only reason it was being brought up was to make sure the astronauts were not surprised by a question from reporters during upcoming interviews.

As it turned out, no reporters ever asked about the foam strike. But the wording of the email gave commander Rick Husband and pilot William "Willie" McCool no reason to question the conclusion that Columbia was in no danger. And indeed, the commander replied in a light-hearted manner, even making a small play on words and ending an email with a "smiley" - :) - face.

The email exchange was posted on a NASA website today. The full text follows (PAO: public affairs office; MCC/POCC: mission control center/payload operations control center; FD: flight day; chine: area of wing near the fuselage):

Rick and Willie,

You guys are doing a fantastic job staying on the timeline and accomplishing great science. Keep up the good work and let us know if there is anything that we can do better from an MCC/POCC standpoint.

There is one item that I would like to make you aware of for the upcoming PAO event on Blue FD 10 and for future PAO events later in the mission. This item is not even worth mentioning other than wanting to make sure that you are not surprised by it in a question from a reporter.

During ascent at approximately 80 seconds, photo analysis shows that some debris from the area of the -Y ET Bipod Attach Point came loose and subsequently impacted the orbiter left wing, in the area of transition from Chine to Main Wing, creating a shower of smaller particles. The impact appears to be totally on the lower surface and no particles are seen to traverse over the upper surface of the wing. Experts have reviewed the high speed photography and there is no concern for RCC or tile damage. We have seen this same phenomenon on several other flights and there is absolutely no concern for entry.

That is all for now. It's a pleasure working with you every day.

Husband replied to flight director Steve Stich the following day - Jan. 24 - saying "Thanks a million Steve!"

"And thanks for the great work on your part AND for the great poems!" Husband emailed. "I saw the word Chine below and thought it was "China". I guess it's believeable (sic) that you might meet someone from China by the name of Main Wing :)." Mission control uplinked a video of the foam strike Jan. 25 and Husband replied the next day, saying only "thanks for the super work! We appreciate it."

In hindsight, the emails are disturbing because of the remarkably casual manner in which the foam strike, the worst in shuttle history, was dismissed. Other emails that were released after Columbia's Feb. 1 destruction showed mid-level engineers were concerned about potentially severe re-entry damage all the way until the day before landing.

The Columbia Accident Investigation Board now believes the foam strike is the most probable cause of the Columbia disaster.

Eighty-one seconds after Columbia's launching, a suitcase-size chunk of foam insulation broke away from the shuttle's external fuel tank and slammed into the leading edge of the ship's left wing.

The foam strike was discovered during routine post-launch video analysis on Jan. 17. Mission managers promptly ordered an engineering assessment to determine whether or not Columbia's heat-shield tiles had been damaged enough to compromise safety during re-entry. An analysis carried out by Boeing concluded that while possibly severe heat damage to the underlying skin might require post-landing repairs, the impact did not pose a "safety of flight" issue.

The analysis indicated any impact on the reinforced carbon carbon leading edge panels would do little more than mar the coating. As it turned out, the analysis was deeply flawed. The engineers extrapolated from an earlier tile-impact study involving much smaller pieces of debris and had virtually no data at all regarding how such strikes might affect RCC panels. Post-accident analyses, impact tests using a nitrogen gas cannon, enhanced launch video and sensor data all indicated the 1.67-pound chunk of foam, which hit the leading edge at more than 500 mph, caused a breach that allowed super-heated air to burn its way inside during Columbia's re-entry Feb. 1. The wing ultimately failed and Columbia was destroyed.

But NASA's mission management team accepted the results of the Boeing analysis, quashed efforts to obtain spy satellite photography that might have resolved the issue one way or the other and informed the crew about the impact only in passing.

But according to a just-released transcript of internal mission control communications loops, the foam strike, or a debris impact of some sort, clearly was on the minds of flight controllers when the first signs of trouble developed during Columbia's return to Earth. Mechanical systems officer Jeffrey Kling - MMACS - was the man who first informed flight director Leroy Cain about unusual telemetry from Columbia's left wing. Kling, in turn, was backed up by other mechanical systems, or MECH, engineers, including Ken Smith and David Lechner, in a nearby support room.

"What in the world?" one of the MECH engineers wondered when the first sensor data dropped off line.

"This is not funny," Kling replied. "On the left side."

"On the left side," MECH agreed.

Seconds later, at 08:54:24 a.m., Kling informed Cain.

"FLIGHT, MMACS."

"Go ahead, MMACS."

"FYI, I've just lost four separate temperature transducers on the left side of the vehicle, hydraulic return temperatures. Two of them on system one and one in each of systems two and three. To the left outboard and left inboard elevon."

Columbia was passing over the California-Nevada state line at 22.5 times the speed of sound at an altitude of 227,400 feet. Seconds later, observers on the ground noticed a bright flash in the shuttle's plasma trail followed by the sixth known incident of debris falling away from the orbiter.

Kling's discussion with Cain has been posted previously, but the internal dialogue between Kling and the MECH officers sheds a chilling new light on the events of Feb. 1.

"OK, is there anything common to them? DSC (discrete signal conditioner) or MDM (multiplexer-dem