20 years after the Space Shuttle Columbia disaster, lessons learned are still the focus of NASA

Twenty years ago this Wednesday, February 1, 2003, at 8:48:39 am EST, a sensor in the left wing of the Space Shuttle Columbia recorded unusual stress for the first time as the orbiter and seven of its crew members returned to Earth, to complete the flight. successful 16-day science mission.

Over the next 12 minutes, the onboard data recorder tracked a cascade of alarming sensor readings and failures on the left side of the spacecraft, indicating a rapidly escalating disaster as the blazing heat of re-entry engulfed the craft.

But it was originally played out behind the scenes in the ship’s battle computers, which fought an increasingly desperate fight to keep the Columbia on track for its scheduled landing at the Kennedy Space Center in Florida, where friends and family were waiting.

So, at 8:53:26 a.m., the Columbia crossed the coast of California on schedule at 44 miles, traveling at 23 times the speed of sound.

Space enthusiasts in the western United States will be filming dramatic video of the Columbia’s descent at dawn, including unusual changes in the shuttle’s white-hot plasma trail, and flashes of light separating and disappearing. At the time, no one knew what this light show might mean.

But 16 days ago, 81.7 seconds after liftoff, a briefcase-sized piece of lightweight foam insulation ripped off Columbia’s external tank as the spacecraft accelerated to 1,500 miles per hour.

Security cameras showed that the foam disappeared under the shuttle’s left wing and reappeared a moment later as a cloud of small particles. Later analysis indicated that the foam hit the underside of the left wing at a relative velocity of over 500 mph and disintegrated instantly.

Engineers couldn’t pinpoint exactly where the foam had hit, and Columbia didn’t have a robotic arm capable of inspecting it in space.

But engineering analysis based on software simulations of much smaller impacts has shown that foam impact does not pose a “flight safety” problem. Senior managers ruled out the possibility of requesting spy satellite imagery that might or might not allow for a more thorough analysis.

In any case, Commander Rick Husband, pilot Willie McCool, mission specialists Kalpana Chawla, Laurel Clark, Michael Anderson, David Brown, and visiting Israeli astronaut Ilan Ramon were unaware of any problems when they returned to Earth, admiring the pink glow from the cockpit. windows, because atmospheric friction had occurred moments before the first unusual sensor reading.

Then, around 8:54:24 a.m. — 5 minutes and 45 seconds after the initial reading was stored in the data logger — the first signs of a malfunction appeared in the telemetry reaching flight controllers at the Johnson Space Center in Houston: a loss of temperature. Readings of hydraulic lines in Columbia’s left wing.

Four minutes later, Columbia’s back-up on-board computer displayed a message in the cockpit that the left main landing gear tire pressure reading had been lost. The husband called mission control, presumably to ask about tire pressure, but his connection was cut off.

“Columbia, Houston, we see your tire pressure messages and we didn’t copy your latest,” astronaut Charles Hobo called from Houston.

“Roger, uh,” Husband began. But again the transmission was interrupted. It was 8:59:32

As the engineers later learned, the Columbia went out of control in the ensuing seconds and broke apart 38 miles over central Texas, moving at 18 times the speed of sound. All seven astronauts, who passed out moments after the flight deck lost pressure, were killed by blunt trauma when the cabin broke apart in the hypersonic airflow.

It took another two and a half minutes for the harsh reality of Columbia’s death to reach Kennedy Space Center, where family members, NASA managers, ground support team, reporters and photographers waited for the shuttle to return home.

In the days, weeks, and months that followed, the Columbia University Air Accident Investigation Board uncovered a now-known story of external tank foam insulation problems, management errors, and poor internal communications that contributed to the accident.

In a dramatic test, the engineers used an air cannon to fire a piece of outer tank foam at a mock wing leading edge at the same angle and speed as the one that damaged the Columbia. The impact left a hole in the front edge of the mock-up, proving conclusively that light insulation can lead to catastrophic damage in the worst case.

This is exactly what happened to Colombia.

During reentry, superheated air rushed through a gap in the leading edge of the left wing, severed the sensor wiring, melted the inner spars, and burned through the left landing gear wheel well. Eventually the wing either collapsed or broke away from the fuselage, causing the ship to spin out of control.

The Columbia disaster, like the Challenger before it, set off a soul-searching throughout the agency as the accident investigation continued.

  • CBS News recalled the disaster in Colombia in 2016. Watch this video in the player below:

Today in History: Space Shuttle Columbia Disaster 03:13

The NASA mission control team was criticized for deflecting the foam strike based on what turned out to be faulty engineering analysis. The shuttle was not equipped with a robotic arm, tools, or materials to repair major damage to the heat shield, and MMT never considered a risky emergency spacewalk to inspect the damage site.

Although a NASA study later showed that a shuttle rescue mission was theoretically possible, no one believed that the agency would launch another crew without first knowing what had happened to Columbia.

In short, the fate of Colombia was sealed 81.7 seconds after launch. The real problem, the accident board concluded, was that previously NASA had failed to adequately address a persistent problem: debris from the heat shield hitting foam insulation ripping off the outer tank during ascent.

As was well known, each shuttle flight was accompanied by foam hitting the orbiter’s heat shield, although the agency had a clear rule against hitting debris. This rule was never strictly enforced, and eventually NASA came to view foam shedding as an “acceptable risk”.

But fears about foam intensified in October 2002, just two flights before the Columbia flight, when a letterbox-sized piece of insulation blew off seconds after liftoff from the space shuttle Atlantis’ external tank. The debris cut into the insulation covering the mounting ring at the base of the solid booster, leaving a funnel 4 inches wide and 3 inches deep.

It was a close call. The foam hit just six inches from the critical electronic box used to relay commands to the booster from the shuttle’s onboard computers.

Engineers quickly traced the missing foam to one of the two bipod ramps, where insulation was built around the bases of the two struts used to hold the orbiter’s nose to the tank.

On October 31, 2002, NASA leaders met at the Kennedy Space Center for a flight readiness review to discuss the planned launch of the Endeavor shuttle for the next space station assembly mission.

The loss of foam during the launch of Atlantis earlier in October was just one of several technical issues discussed on the table, and meeting chairman Bill Riddy, a former shuttle commander who served as NASA’s deputy administrator for spaceflight, warned everyone to be vigilant.

But in the discussion that followed, tank managers and engineers argued that problems with the Endeavor tank were no more or less likely than with earlier tanks built in the same way. There was no clear evidence that anything was wrong with the next tank in the sequence, and while foaming was common, loss of large pieces was rare.

They could not guarantee that the upcoming flight would be free of significant foam debris, but the external tanker crew concluded that the Endeavor was “safe to fly with no new problems (and no additional risk).”

Despite what some saw as the somewhat suspicious “justification for the flight”, the flight readiness review culminated in an official launch clearance. There was no significant foam damage on the Endeavor flight, and when NASA managers met on January 9, 2003 to review Columbia’s readiness, foam dumping was not on the agenda.

Analyzing the Challenger disaster, sociologist Diane Vaughan called this kind of acceptance of a well-known problem “the normalization of deviance.”

So in this context, the beginning of the end came on Halloween 2002, when Endeavor flight readiness testers agreed to keep flying shuttles before getting a full understanding of the foam bipod problem.

The impact of this decision still affects the entire space program.

Along with the recommended technical and management changes, the Colombian Accident Investigation Board told NASA that it must “re-certify the vehicle at the material, component, subsystem and system level” if the agency wants to launch the shuttle after 2010, which was extremely expensive.

Instead, in January 2004, President George W. Bush ordered NASA to decommission the shuttle fleet after the completion of the International Space Station. The idea was to free up money for the new rockets and spacecraft needed to build Antarctica-style moon bases in the early 2020s.

Needed to support space station crew and cargo flights after the shuttle was retired, NASA turned to the private sector to develop commercial cargo planes and space taxis to deliver supplies and transport astronauts to and from the laboratory complex.

SpaceX and Orbital Sciences (now Northrop Grumman) launched the first commercial cargo ships in 2012 and 2013, respectively. SpaceX launched the first astronauts on a Crew Dragon capsule in 2020, ending NASA’s reliance on Russia for basic crew transportation. Boeing is expected to follow suit later this year with its Starliner capsule.

But President Bush’s lunar program, Constellation, never got enough funding, and the Obama administration decided it wasn’t viable. NASA was ordered to continue development of the Orion crew capsule of the Constellation program and build a new rocket, which became the space launch system, for deep space exploration.

Then, in 2017, President Trump ordered NASA to speed up the stalled lunar program. As a result, late last year, the Artemis program launched the first unmanned flight using an SLS rocket and an Orion capsule. The agency plans to send four astronauts to fly around the moon – Artemis 2 – in 2024, and then land on the moon in 2025-2026.

But in the immediate aftermath of the Columbia disaster, NASA’s path to the present was even remotely unimaginable. All that was known was that the names of seven more men and women would be inscribed on the Kennedy Space Center memorial.

And there were harder lessons to be learned again.

“Every day at NASA, we have the opportunity, we have the responsibility to carry the memories of those we have lost and carry their dreams forward and upward,” NASA Administrator Bill Nelson told agency staff last week.

“And the bottom line is this: speak up. A question, even a simple question, is more forgivable than a mistake that can lead to tragedy. And each of us has a responsibility to create a working environment in which every member of the NASA family feels entitled to voice their doubts. Make sure your concerns are heard.”

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